qssgrenderer.cpp

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// Copyright (C) 2008-2012 NVIDIA Corporation.
// Copyright (C) 2019 The Qt Company Ltd.
// SPDX-License-Identifier: LicenseRef-Qt-Commercial OR GPL-3.0-only
 
#include <QtQuick3DRuntimeRender/private/qssgrenderitem2d_p.h>
#include <QtQuick3DRuntimeRender/private/qssgrenderer_p.h>
#include <QtQuick3DRuntimeRender/private/qssgrendercontextcore_p.h>
#include <QtQuick3DRuntimeRender/private/qssgrendercamera_p.h>
#include <QtQuick3DRuntimeRender/private/qssgrenderlight_p.h>
#include <QtQuick3DRuntimeRender/private/qssgrenderimage_p.h>
#include <QtQuick3DRuntimeRender/private/qssgrenderbuffermanager_p.h>
#include <QtQuick3DRuntimeRender/private/qssgrendercontextcore_p.h>
#include <QtQuick3DRuntimeRender/private/qssgrendereffect_p.h>
#include <QtQuick3DRuntimeRender/private/qssgrhicustommaterialsystem_p.h>
#include <QtQuick3DRuntimeRender/private/qssgrendershadercodegenerator_p.h>
#include <QtQuick3DRuntimeRender/private/qssgrenderdefaultmaterialshadergenerator_p.h>
#include <QtQuick3DRuntimeRender/private/qssgperframeallocator_p.h>
#include <QtQuick3DRuntimeRender/private/qssgrhiquadrenderer_p.h>
#include <QtQuick3DRuntimeRender/private/qssgrendertexturedata_p.h>
#include <QtQuick3DRuntimeRender/private/qssglayerrenderdata_p.h>
#include <QtQuick3DRuntimeRender/private/qssgrhiparticles_p.h>
 
#include <QtQuick3DUtils/private/qquick3dprofiler_p.h>
#include <QtQuick3DUtils/private/qssgdataref_p.h>
#include <QtQuick3DUtils/private/qssgutils_p.h>
#include <QtQuick3DUtils/private/qssgassert_p.h>
#include <qtquick3d_tracepoints_p.h>
 
#include <QtCore/QMutexLocker>
#include <QtCore/QBitArray>
 
#include <cstdlib>
#include <algorithm>
#include <limits>
 
QT_BEGIN_NAMESPACE
 
struct QSSGRenderableImage;
struct QSSGSubsetRenderable;
 
static constexpr float QSSG_PI = float(M_PI);
static constexpr float QSSG_HALFPI = float(M_PI_2);
 
static const QRhiShaderResourceBinding::StageFlags RENDERER_VISIBILITY_ALL =
        QRhiShaderResourceBinding::VertexStage | QRhiShaderResourceBinding::FragmentStage;
 
static QSSGRhiShaderPipelinePtr shadersForDefaultMaterial(QSSGRhiGraphicsPipelineState *ps,
                                                          QSSGSubsetRenderable &subsetRenderable,
                                                          const QSSGShaderFeatures &featureSet)
{
    const auto &renderer(subsetRenderable.renderer);
    const auto &shaderPipeline = renderer->getShaderPipelineForDefaultMaterial(subsetRenderable, featureSet);
    if (shaderPipeline)
        ps->shaderPipeline = shaderPipeline.get();
    return shaderPipeline;
}
 
static QSSGRhiShaderPipelinePtr shadersForParticleMaterial(QSSGRhiGraphicsPipelineState *ps,
                                                           QSSGParticlesRenderable &particleRenderable)
{
    const auto &renderer(particleRenderable.renderer);
    auto featureLevel = particleRenderable.particles.m_featureLevel;
    const auto &shaderPipeline = renderer->getRhiParticleShader(featureLevel);
    if (shaderPipeline)
        ps->shaderPipeline = shaderPipeline.get();
    return shaderPipeline;
}
 
static void updateUniformsForDefaultMaterial(QSSGRhiShaderPipeline &shaderPipeline,
                                             QSSGRhiContext *rhiCtx,
                                             const QSSGLayerRenderData &inData,
                                             char *ubufData,
                                             QSSGRhiGraphicsPipelineState *ps,
                                             QSSGSubsetRenderable &subsetRenderable,
                                             const QSSGRenderCamera &camera,
                                             const QVector2D *depthAdjust,
                                             const QMatrix4x4 *alteredModelViewProjection)
{
    const auto &renderer(subsetRenderable.renderer);
    const QMatrix4x4 clipSpaceCorrMatrix = rhiCtx->rhi()->clipSpaceCorrMatrix();
    const QMatrix4x4 &mvp(alteredModelViewProjection ? *alteredModelViewProjection
                                                     : subsetRenderable.modelContext.modelViewProjection);
 
    const auto &modelNode = subsetRenderable.modelContext.model;
    QRhiTexture *lightmapTexture = inData.getLightmapTexture(subsetRenderable.modelContext);
 
    const QMatrix4x4 &localInstanceTransform(modelNode.localInstanceTransform);
    const QMatrix4x4 &globalInstanceTransform(modelNode.globalInstanceTransform);
    const QMatrix4x4 &modelMatrix(modelNode.usesBoneTexture() ? QMatrix4x4() : subsetRenderable.globalTransform);
 
    QSSGMaterialShaderGenerator::setRhiMaterialProperties(*renderer->contextInterface(),
                                                          shaderPipeline,
                                                          ubufData,
                                                          ps,
                                                          subsetRenderable.material,
                                                          subsetRenderable.shaderDescription,
                                                          renderer->defaultMaterialShaderKeyProperties(),
                                                          camera,
                                                          mvp,
                                                          subsetRenderable.modelContext.normalMatrix,
                                                          modelMatrix,
                                                          clipSpaceCorrMatrix,
                                                          localInstanceTransform,
                                                          globalInstanceTransform,
                                                          toDataView(modelNode.morphWeights),
                                                          subsetRenderable.firstImage,
                                                          subsetRenderable.opacity,
                                                          renderer->getLayerGlobalRenderProperties(),
                                                          subsetRenderable.lights,
                                                          subsetRenderable.reflectionProbe,
                                                          subsetRenderable.renderableFlags.receivesShadows(),
                                                          subsetRenderable.renderableFlags.receivesReflections(),
                                                          depthAdjust,
                                                          lightmapTexture);
}
 
void QSSGRenderer::releaseCachedResources()
{
    delete m_rhiQuadRenderer;
    m_rhiQuadRenderer = nullptr;
    delete m_rhiCubeRenderer;
    m_rhiCubeRenderer = nullptr;
}
 
QSSGRenderer::QSSGRenderer() = default;
 
QSSGRenderer::~QSSGRenderer()
{
    m_contextInterface = nullptr;
    releaseCachedResources();
}
 
void QSSGRenderer::setRenderContextInterface(QSSGRenderContextInterface *ctx)
{
    m_contextInterface = ctx;
}
 
bool QSSGRenderer::prepareLayerForRender(QSSGRenderLayer &inLayer)
{
    QSSGLayerRenderData *theRenderData = getOrCreateLayerRenderData(inLayer);
    Q_ASSERT(theRenderData);
    beginLayerRender(*theRenderData);
    theRenderData->resetForFrame();
    theRenderData->prepareForRender();
    endLayerRender();
    return theRenderData->layerPrepResult->flags.wasDirty();
}
 
// Phase 1: prepare. Called when the renderpass is not yet started on the command buffer.
void QSSGRenderer::rhiPrepare(QSSGRenderLayer &inLayer)
{
    QSSGLayerRenderData *theRenderData = getOrCreateLayerRenderData(inLayer);
    QSSG_ASSERT(theRenderData && theRenderData->camera, return);
 
    const auto layerPrepResult = theRenderData->layerPrepResult;
    if (layerPrepResult->isLayerVisible()) {
        QSSGRhiContext *rhiCtx = contextInterface()->rhiContext().get();
        QSSG_ASSERT(rhiCtx->isValid() && rhiCtx->rhi()->isRecordingFrame(), return);
        theRenderData->maybeBakeLightmap();
        beginLayerRender(*theRenderData);
        // Process active passes. "PreMain" passes are individual passes
        // that does can and should be done in the rhi prepare phase.
        // It is assumed that passes are sorted in the list with regards to
        // execution order.
        const auto &activePasses = theRenderData->activePasses;
        for (const auto &pass : activePasses) {
            pass->renderPrep(*this, *theRenderData);
            if (pass->passType() == QSSGRenderPass::Type::Standalone)
                pass->renderPass(*this);
        }
 
        endLayerRender();
    }
}
 
// Phase 2: render. Called within an active renderpass on the command buffer.
void QSSGRenderer::rhiRender(QSSGRenderLayer &inLayer)
{
    QSSGLayerRenderData *theRenderData = getOrCreateLayerRenderData(inLayer);
    QSSG_ASSERT(theRenderData && theRenderData->camera, return);
    if (theRenderData->layerPrepResult->isLayerVisible()) {
        QSSG_ASSERT(theRenderData->camera, return);
        beginLayerRender(*theRenderData);
        const auto &activePasses = theRenderData->activePasses;
        for (const auto &pass : activePasses) {
            if (pass->passType() == QSSGRenderPass::Type::Main || pass->passType() == QSSGRenderPass::Type::Extension)
                pass->renderPass(*this);
        }
        endLayerRender();
    }
}
 
template<typename Container>
static void cleanupResourcesImpl(const QSSGRenderContextInterface &rci, const Container &resources)
{
    const auto &rhi = rci.rhiContext();
    if (!rhi->isValid())
        return;
 
    const auto &bufferManager = rci.bufferManager();
 
    for (const auto &resource : resources) {
        if (resource->type == QSSGRenderGraphObject::Type::Geometry) {
            auto geometry = static_cast<QSSGRenderGeometry*>(resource);
            bufferManager->releaseGeometry(geometry);
        } else if (resource->type == QSSGRenderGraphObject::Type::Model) {
            auto model = static_cast<QSSGRenderModel*>(resource);
            rhi->cleanupDrawCallData(model);
        } else if (resource->type == QSSGRenderGraphObject::Type::TextureData) {
            auto textureData = static_cast<QSSGRenderTextureData *>(resource);
            bufferManager->releaseTextureData(textureData);
        }
 
        // ### There might be more types that need to be supported
 
        delete resource;
    }
}
 
void QSSGRenderer::cleanupResources(QList<QSSGRenderGraphObject *> &resources)
{
    cleanupResourcesImpl(*m_contextInterface, resources);
    resources.clear();
}
 
void QSSGRenderer::cleanupResources(QSet<QSSGRenderGraphObject *> &resources)
{
    cleanupResourcesImpl(*m_contextInterface, resources);
    resources.clear();
}
 
QSSGLayerRenderData *QSSGRenderer::getOrCreateLayerRenderData(QSSGRenderLayer &layer)
{
    if (layer.renderData == nullptr)
        layer.renderData = new QSSGLayerRenderData(layer, *this);
 
    return layer.renderData;
}
 
void QSSGRenderer::addMaterialDirtyClear(QSSGRenderGraphObject *material)
{
    m_materialClearDirty.insert(material);
}
 
static QByteArray logPrefix() { return QByteArrayLiteral("mesh default material pipeline-- "); }
 
 
QSSGRhiShaderPipelinePtr QSSGRenderer::generateRhiShaderPipelineImpl(QSSGSubsetRenderable &renderable,
                                                                     QSSGShaderLibraryManager &shaderLibraryManager,
                                                                     QSSGShaderCache &shaderCache,
                                                                     QSSGProgramGenerator &shaderProgramGenerator,
                                                                     QSSGShaderDefaultMaterialKeyProperties &shaderKeyProperties,
                                                                     const QSSGShaderFeatures &featureSet,
                                                                     QByteArray &shaderString)
{
    shaderString = logPrefix();
    QSSGShaderDefaultMaterialKey theKey(renderable.shaderDescription);
 
    // This is not a cheap operation. This function assumes that it will not be
    // hit for every material for every model in every frame (except of course
    // for materials that got changed). In practice this is ensured by the
    // cheaper-to-lookup cache in getShaderPipelineForDefaultMaterial().
    theKey.toString(shaderString, shaderKeyProperties);
 
    // Check the in-memory, per-QSSGShaderCache (and so per-QQuickWindow)
    // runtime cache. That may get cleared upon an explicit call to
    // QQuickWindow::releaseResources(), but will otherwise store all
    // encountered shader pipelines in any View3D in the window.
    if (const auto &maybePipeline = shaderCache.tryGetRhiShaderPipeline(shaderString, featureSet))
        return maybePipeline;
 
    // Check if there's a pre-built (offline generated) shader for available.
    const QByteArray qsbcKey = QQsbCollection::EntryDesc::generateSha(shaderString, QQsbCollection::toFeatureSet(featureSet));
    const QQsbCollection::EntryMap &pregenEntries = shaderLibraryManager.m_preGeneratedShaderEntries;
    if (!pregenEntries.isEmpty()) {
        const auto foundIt = pregenEntries.constFind(QQsbCollection::Entry(qsbcKey));
        if (foundIt != pregenEntries.cend())
            return shaderCache.newPipelineFromPregenerated(shaderString, featureSet, *foundIt, renderable.material);
    }
 
    // Try the persistent (disk-based) cache then.
    if (const auto &maybePipeline = shaderCache.tryNewPipelineFromPersistentCache(qsbcKey, shaderString, featureSet))
        return maybePipeline;
 
    // Otherwise, build new shader code and run the resulting shaders through
    // the shader conditioning pipeline.
    QSSGMaterialVertexPipeline vertexPipeline(shaderProgramGenerator,
                                              shaderKeyProperties,
                                              renderable.defaultMaterial().adapter);
 
    return QSSGMaterialShaderGenerator::generateMaterialRhiShader(logPrefix(),
                                                                  vertexPipeline,
                                                                  renderable.shaderDescription,
                                                                  shaderKeyProperties,
                                                                  featureSet,
                                                                  renderable.material,
                                                                  renderable.lights,
                                                                  renderable.firstImage,
                                                                  shaderLibraryManager,
                                                                  shaderCache);
}
 
QSSGRhiShaderPipelinePtr QSSGRenderer::generateRhiShaderPipeline(QSSGSubsetRenderable &inRenderable,
                                                                 const QSSGShaderFeatures &inFeatureSet)
{
    const auto &theCache = m_contextInterface->shaderCache();
    const auto &shaderProgramGenerator = contextInterface()->shaderProgramGenerator();
    const auto &shaderLibraryManager = contextInterface()->shaderLibraryManager();
    return generateRhiShaderPipelineImpl(inRenderable, *shaderLibraryManager, *theCache, *shaderProgramGenerator, m_defaultMaterialShaderKeyProperties, inFeatureSet, m_generatedShaderString);
}
 
void QSSGRenderer::beginFrame(QSSGRenderLayer *layer)
{
    QSSGRHICTX_STAT(m_contextInterface->rhiContext().get(), start(layer));
}
 
void QSSGRenderer::endFrame(QSSGRenderLayer *layer)
{
    // We need to do this endFrame(), as the material nodes might not exist after this!
    for (auto *matObj : std::as_const(m_materialClearDirty)) {
        if (matObj->type == QSSGRenderGraphObject::Type::CustomMaterial) {
            static_cast<QSSGRenderCustomMaterial *>(matObj)->clearDirty();
        } else if (matObj->type == QSSGRenderGraphObject::Type::DefaultMaterial ||
                   matObj->type == QSSGRenderGraphObject::Type::PrincipledMaterial ||
                   matObj->type == QSSGRenderGraphObject::Type::SpecularGlossyMaterial) {
            static_cast<QSSGRenderDefaultMaterial *>(matObj)->clearDirty();
        }
    }
    m_materialClearDirty.clear();
 
    QSSGRHICTX_STAT(m_contextInterface->rhiContext().get(), stop(layer));
}
 
QSSGRenderer::PickResultList QSSGRenderer::syncPickAll(const QSSGRenderLayer &layer,
                                                       QSSGBufferManager &bufferManager,
                                                       const QSSGRenderRay &ray)
{
    PickResultList pickResults;
    Q_ASSERT(layer.getGlobalState(QSSGRenderNode::GlobalState::Active));
    getLayerHitObjectList(layer, bufferManager, ray, m_globalPickingEnabled, pickResults);
    // Things are rendered in a particular order and we need to respect that ordering.
    std::stable_sort(pickResults.begin(), pickResults.end(), [](const QSSGRenderPickResult &lhs, const QSSGRenderPickResult &rhs) {
        return lhs.m_distanceSq < rhs.m_distanceSq;
    });
    return pickResults;
}
 
QSSGRenderPickResult QSSGRenderer::syncPick(const QSSGRenderLayer &layer,
                                            QSSGBufferManager &bufferManager,
                                            const QSSGRenderRay &ray,
                                            QSSGRenderNode *target)
{
    static const auto processResults = [](PickResultList &pickResults) {
        if (pickResults.empty())
            return QSSGPickResultProcessResult();
        // Things are rendered in a particular order and we need to respect that ordering.
        std::stable_sort(pickResults.begin(), pickResults.end(), [](const QSSGRenderPickResult &lhs, const QSSGRenderPickResult &rhs) {
            return lhs.m_distanceSq < rhs.m_distanceSq;
        });
        return QSSGPickResultProcessResult{ pickResults.at(0), true };
    };
 
    Q_ASSERT(layer.getGlobalState(QSSGRenderNode::GlobalState::Active));
    PickResultList pickResults;
    if (target) {
        // Pick against only one target
        intersectRayWithSubsetRenderable(bufferManager, ray, *target, pickResults);
        return processResults(pickResults);
    } else {
        getLayerHitObjectList(layer, bufferManager, ray, m_globalPickingEnabled, pickResults);
        QSSGPickResultProcessResult retval = processResults(pickResults);
        if (retval.m_wasPickConsumed)
            return retval;
    }
 
    return QSSGPickResultProcessResult();
}
 
bool QSSGRenderer::isGlobalPickingEnabled() const
{
    return m_globalPickingEnabled;
}
 
void QSSGRenderer::setGlobalPickingEnabled(bool isEnabled)
{
    m_globalPickingEnabled = isEnabled;
}
 
QSSGRhiQuadRenderer *QSSGRenderer::rhiQuadRenderer()
{
    if (!m_contextInterface->rhiContext()->isValid())
        return nullptr;
 
    if (!m_rhiQuadRenderer)
        m_rhiQuadRenderer = new QSSGRhiQuadRenderer;
 
    return m_rhiQuadRenderer;
}
 
QSSGRhiCubeRenderer *QSSGRenderer::rhiCubeRenderer()
{
    if (!m_contextInterface->rhiContext()->isValid())
        return nullptr;
 
    if (!m_rhiCubeRenderer)
        m_rhiCubeRenderer = new QSSGRhiCubeRenderer;
 
    return m_rhiCubeRenderer;
 
}
 
void QSSGRenderer::beginLayerRender(QSSGLayerRenderData &inLayer)
{
    m_currentLayer = &inLayer;
}
void QSSGRenderer::endLayerRender()
{
    m_currentLayer = nullptr;
}
 
bool QSSGRenderer::rendererRequestsFrames() const
{
    return m_progressiveAARenderRequest;
}
 
using RenderableList = QVarLengthArray<const QSSGRenderNode *>;
static void dfs(const QSSGRenderNode &node, RenderableList &renderables)
{
    if (QSSGRenderGraphObject::isRenderable(node.type))
        renderables.push_back(&node);
 
    for (const auto &child : node.children)
        dfs(child, renderables);
}
 
void QSSGRenderer::getLayerHitObjectList(const QSSGRenderLayer &layer,
                                         QSSGBufferManager &bufferManager,
                                         const QSSGRenderRay &ray,
                                         bool inPickEverything,
                                         PickResultList &outIntersectionResult)
{
    RenderableList renderables;
    for (const auto &childNode : layer.children)
        dfs(childNode, renderables);
 
    for (int idx = renderables.size() - 1; idx >= 0; --idx) {
        const auto &pickableObject = renderables.at(idx);
        if (inPickEverything || pickableObject->getLocalState(QSSGRenderNode::LocalState::Pickable))
            intersectRayWithSubsetRenderable(bufferManager, ray, *pickableObject, outIntersectionResult);
    }
}
 
void QSSGRenderer::intersectRayWithSubsetRenderable(QSSGBufferManager &bufferManager,
                                                    const QSSGRenderRay &inRay,
                                                    const QSSGRenderNode &node,
                                                    QSSGRenderer::PickResultList &outIntersectionResultList)
{
    // Item2D's requires special handling
    if (node.type == QSSGRenderGraphObject::Type::Item2D) {
        const QSSGRenderItem2D &item2D = static_cast<const QSSGRenderItem2D &>(node);
        intersectRayWithItem2D(inRay, item2D, outIntersectionResultList);
        return;
    }
 
    if (node.type != QSSGRenderGraphObject::Type::Model)
        return;
 
    const QSSGRenderModel &model = static_cast<const QSSGRenderModel &>(node);
 
    // We have to have a guard here, as the meshes are usually loaded on the render thread,
    // and we assume all meshes are loaded before picking and none are removed, which
    // is usually true, except for custom geometry which can be updated at any time. So this
    // guard should really only be locked whenever a custom geometry buffer is being updated
    // on the render thread.  Still naughty though because this can block the render thread.
    QMutexLocker mutexLocker(bufferManager.meshUpdateMutex());
    auto mesh = bufferManager.getMeshForPicking(model);
    if (!mesh)
        return;
 
    const auto &subMeshes = mesh->subsets;
    QSSGBounds3 modelBounds;
    for (const auto &subMesh : subMeshes)
        modelBounds.include(subMesh.bounds);
 
    if (modelBounds.isEmpty())
        return;
 
    const bool instancing = model.instancing(); // && instancePickingEnabled
    int instanceCount = instancing ? model.instanceTable->count() : 1;
 
    for (int instanceIndex = 0; instanceIndex < instanceCount; ++instanceIndex) {
 
        QMatrix4x4 modelTransform;
        if (instancing) {
            modelTransform = model.globalInstanceTransform * model.instanceTable->getTransform(instanceIndex) * model.localInstanceTransform;
        } else {
            modelTransform = model.globalTransform;
        }
        auto rayData = QSSGRenderRay::createRayData(modelTransform, inRay);
 
        auto hit = QSSGRenderRay::intersectWithAABBv2(rayData, modelBounds);
 
        // If we don't intersect with the model at all, then there's no need to go furher down!
        if (!hit.intersects())
            continue;
 
        // Check each submesh to find the closest intersection point
        float minRayLength = std::numeric_limits<float>::max();
        QSSGRenderRay::IntersectionResult intersectionResult;
        QVector<QSSGRenderRay::IntersectionResult> results;
 
        int subset = 0;
        int resultSubset = 0;
        for (const auto &subMesh : subMeshes) {
            QSSGRenderRay::IntersectionResult result;
            if (subMesh.bvhRoot) {
                hit = QSSGRenderRay::intersectWithAABBv2(rayData, subMesh.bvhRoot->boundingData);
                if (hit.intersects()) {
                    results.clear();
                    inRay.intersectWithBVH(rayData, subMesh.bvhRoot, mesh, results);
                    float subMeshMinRayLength = std::numeric_limits<float>::max();
                    for (const auto &subMeshResult : std::as_const(results)) {
                        if (subMeshResult.rayLengthSquared < subMeshMinRayLength) {
                            result = subMeshResult;
                            subMeshMinRayLength = result.rayLengthSquared;
                        }
                    }
                }
            } else {
                hit = QSSGRenderRay::intersectWithAABBv2(rayData, subMesh.bounds);
                if (hit.intersects())
                    result = QSSGRenderRay::createIntersectionResult(rayData, hit);
            }
            if (result.intersects && result.rayLengthSquared < minRayLength) {
                intersectionResult = result;
                minRayLength = intersectionResult.rayLengthSquared;
                resultSubset = subset;
            }
            subset++;
        }
 
        if (intersectionResult.intersects)
            outIntersectionResultList.push_back(QSSGRenderPickResult { &model,
                                                                       intersectionResult.rayLengthSquared,
                                                                       intersectionResult.relXY,
                                                                       intersectionResult.scenePosition,
                                                                       intersectionResult.localPosition,
                                                                       intersectionResult.faceNormal,
                                                                       resultSubset,
                                                                       instanceIndex
                                                });
    }
}
 
void QSSGRenderer::intersectRayWithItem2D(const QSSGRenderRay &inRay, const QSSGRenderItem2D &item2D, QSSGRenderer::PickResultList &outIntersectionResultList)
{
    // Get the plane (and normal) that the item 2D is on
    const QVector3D p0 = item2D.getGlobalPos();
    const QVector3D normal  = -item2D.getDirection();
 
    const float d = QVector3D::dotProduct(inRay.direction, normal);
    float intersectionTime = 0;
    if (d > 1e-6f) {
        const QVector3D p0l0 = p0 - inRay.origin;
        intersectionTime = QVector3D::dotProduct(p0l0, normal) / d;
        if (intersectionTime >= 0) {
            // Intersection
            const QVector3D intersectionPoint = inRay.origin + inRay.direction * intersectionTime;
            const QMatrix4x4 inverseGlobalTransform = item2D.globalTransform.inverted();
            const QVector3D localIntersectionPoint = mat44::transform(inverseGlobalTransform, intersectionPoint);
            const QVector2D qmlCoordinate(localIntersectionPoint.x(), -localIntersectionPoint.y());
            outIntersectionResultList.push_back(QSSGRenderPickResult { &item2D,
                                                                       intersectionTime * intersectionTime,
                                                                       qmlCoordinate,
                                                                       intersectionPoint,
                                                                       localIntersectionPoint,
                                                                       normal });
        }
    }
}
 
QSSGRhiShaderPipelinePtr QSSGRenderer::getShaderPipelineForDefaultMaterial(QSSGSubsetRenderable &inRenderable,
                                                                           const QSSGShaderFeatures &inFeatureSet)
{
    if (Q_UNLIKELY(m_currentLayer == nullptr)) {
        Q_ASSERT(false);
        return nullptr;
    }
 
    // This function is the main entry point for retrieving the shaders for a
    // default material, and is called for every material for every model in
    // every frame. Therefore, like with custom materials, employ a first level
    // cache (a simple hash table), with a key that's quick to
    // generate/hash/compare. Even though there are other levels of caching in
    // the components that get invoked from here, those may not be suitable
    // performance wise. So bail out right here as soon as possible.
 
    QElapsedTimer timer;
    timer.start();
 
    QSSGRhiShaderPipelinePtr shaderPipeline;
 
    // This just references inFeatureSet and inRenderable.shaderDescription -
    // cheap to construct and is good enough for the find()
    QSSGShaderMapKey skey = QSSGShaderMapKey(QByteArray(),
                                             inFeatureSet,
                                             inRenderable.shaderDescription);
    auto it = m_shaderMap.find(skey);
    if (it == m_shaderMap.end()) {
        Q_TRACE_SCOPE(QSSG_generateShader);
        Q_QUICK3D_PROFILE_START(QQuick3DProfiler::Quick3DGenerateShader);
        shaderPipeline = generateRhiShaderPipeline(inRenderable, inFeatureSet);
        Q_QUICK3D_PROFILE_END_WITH_ID(QQuick3DProfiler::Quick3DGenerateShader, 0, inRenderable.material.profilingId);
        // make skey useable as a key for the QHash (makes copies of materialKey and featureSet, instead of just referencing)
        skey.detach();
        // insert it no matter what, no point in trying over and over again
        m_shaderMap.insert(skey, shaderPipeline);
    } else {
        shaderPipeline = it.value();
    }
 
    if (shaderPipeline != nullptr) {
        if (m_currentLayer && m_currentLayer->camera) {
            if (!m_currentLayer->cameraData.has_value())
                [[maybe_unused]] const auto cd = m_currentLayer->getCachedCameraData();
        }
    }
 
    m_contextInterface->rhiContext()->stats().registerMaterialShaderGenerationTime(timer.elapsed());
 
    return shaderPipeline;
}
 
QSSGLayerGlobalRenderProperties QSSGRenderer::getLayerGlobalRenderProperties()
{
    QSSGLayerRenderData &theData = *m_currentLayer;
    const QSSGRenderLayer &theLayer = theData.layer;
    if (!theData.cameraData.has_value() && theData.camera) // NOTE: Ensure we have a valid value!
        [[maybe_unused]] const auto cd = theData.getCachedCameraData();
 
    bool isYUpInFramebuffer = true;
    bool isYUpInNDC = true;
    bool isClipDepthZeroToOne = true;
    if (m_contextInterface->rhiContext()->isValid()) {
        QRhi *rhi = m_contextInterface->rhiContext()->rhi();
        isYUpInFramebuffer = rhi->isYUpInFramebuffer();
        isYUpInNDC = rhi->isYUpInNDC();
        isClipDepthZeroToOne = rhi->isClipDepthZeroToOne();
    }
 
    return QSSGLayerGlobalRenderProperties{ theLayer,
                                              *theData.camera,
                                              theData.cameraData.value(), // ensured/checked further up in this function
                                              theData.getShadowMapManager().get(),
                                              theData.depthMapPass.rhiDepthTexture.texture,
                                              theData.ssaoMapPass.rhiAoTexture.texture,
                                              theData.screenMapPass.rhiScreenTexture.texture,
                                              theLayer.lightProbe,
                                              theLayer.probeHorizon,
                                              theLayer.probeExposure,
                                              theLayer.probeOrientation,
                                              isYUpInFramebuffer,
                                              isYUpInNDC,
                                              isClipDepthZeroToOne};
}
 
void QSSGRenderer::setTonemapFeatures(QSSGShaderFeatures &features, QSSGRenderLayer::TonemapMode tonemapMode)
{
    features.set(QSSGShaderFeatures::Feature::LinearTonemapping,
                 tonemapMode == QSSGRenderLayer::TonemapMode::Linear);
    features.set(QSSGShaderFeatures::Feature::AcesTonemapping,
                 tonemapMode == QSSGRenderLayer::TonemapMode::Aces);
    features.set(QSSGShaderFeatures::Feature::HejlDawsonTonemapping,
                 tonemapMode == QSSGRenderLayer::TonemapMode::HejlDawson);
    features.set(QSSGShaderFeatures::Feature::FilmicTonemapping,
                 tonemapMode == QSSGRenderLayer::TonemapMode::Filmic);
}
 
 
std::pair<QSSGBoxPoints, QSSGBoxPoints> RenderHelpers::calculateSortedObjectBounds(const QVector<QSSGRenderableObjectHandle> &sortedOpaqueObjects,
                                                                                   const QVector<QSSGRenderableObjectHandle> &sortedTransparentObjects)
{
    QSSGBounds3 boundsCasting;
    QSSGBounds3 boundsReceiving;
    for (const auto handles : { &sortedOpaqueObjects, &sortedTransparentObjects }) {
        // Since we may have nodes that are not a child of the camera parent we go through all
        // the opaque objects and include them in the bounds. Failing to do this can result in
        // too small bounds.
        for (const QSSGRenderableObjectHandle &handle : *handles) {
            const QSSGRenderableObject &obj = *handle.obj;
            // We skip objects not casting or receiving shadows since they don't influence or need to be covered by the shadow map
            if (obj.renderableFlags.castsShadows())
                boundsCasting.include(obj.globalBounds);
            if (obj.renderableFlags.receivesShadows())
                boundsReceiving.include(obj.globalBounds);
        }
    }
    return { boundsCasting.toQSSGBoxPointsNoEmptyCheck(), boundsReceiving.toQSSGBoxPointsNoEmptyCheck() };
}
 
static QVector3D calcCenter(const QSSGBoxPoints &vertices)
{
    QVector3D center = vertices[0];
    for (int i = 1; i < 8; ++i) {
        center += vertices[i];
    }
    return center * 0.125f;
}
 
static QSSGBounds3 calculateShadowCameraBoundingBox(const QSSGBoxPoints &points, const QVector3D &forward, const QVector3D &up, const QVector3D &right)
{
    QSSGBounds3 bounds;
    for (int i = 0; i < 8; ++i) {
        const float distanceZ = QVector3D::dotProduct(points[i], forward);
        const float distanceY = QVector3D::dotProduct(points[i], up);
        const float distanceX = QVector3D::dotProduct(points[i], right);
        bounds.include(QVector3D(distanceX, distanceY, distanceZ));
    }
    return bounds;
}
 
static QSSGBoxPoints computeFrustumBounds(const QSSGRenderCamera &inCamera)
{
    QMatrix4x4 viewProjection;
    inCamera.calculateViewProjectionMatrix(viewProjection);
 
    bool invertible = false;
    QMatrix4x4 inv = viewProjection.inverted(&invertible);
    Q_ASSERT(invertible);
 
    return { inv.map(QVector3D(-1, -1, -1)), inv.map(QVector3D(+1, -1, -1)), inv.map(QVector3D(+1, +1, -1)),
             inv.map(QVector3D(-1, +1, -1)), inv.map(QVector3D(-1, -1, +1)), inv.map(QVector3D(+1, -1, +1)),
             inv.map(QVector3D(+1, +1, +1)), inv.map(QVector3D(-1, +1, +1)) };
}
 
static void setupCubeReflectionCameras(const QSSGRenderReflectionProbe *inProbe, QSSGRenderCamera inCameras[6])
{
    Q_ASSERT(inProbe != nullptr);
 
    // setup light matrix
    quint32 mapRes = 1 << inProbe->reflectionMapRes;
    QRectF theViewport(0.0f, 0.0f, (float)mapRes, (float)mapRes);
    static const QQuaternion rotOfs[6] {
                                         QQuaternion::fromEulerAngles(0.f, qRadiansToDegrees(-QSSG_HALFPI), qRadiansToDegrees(QSSG_PI)),
                                         QQuaternion::fromEulerAngles(0.f, qRadiansToDegrees(QSSG_HALFPI), qRadiansToDegrees(QSSG_PI)),
                                         QQuaternion::fromEulerAngles(qRadiansToDegrees(QSSG_HALFPI), 0.f, 0.f),
                                         QQuaternion::fromEulerAngles(qRadiansToDegrees(-QSSG_HALFPI), 0.f, 0.f),
                                         QQuaternion::fromEulerAngles(0.f, qRadiansToDegrees(QSSG_PI), qRadiansToDegrees(-QSSG_PI)),
                                         QQuaternion::fromEulerAngles(0.f, 0.f, qRadiansToDegrees(QSSG_PI)),
                                         };
 
    const QVector3D inProbePos = inProbe->getGlobalPos();
    const QVector3D inProbePivot = inProbe->pivot;
 
    for (int i = 0; i < 6; ++i) {
        inCameras[i].parent = nullptr;
        inCameras[i].clipNear = 1.0f;
        inCameras[i].clipFar = qMax<float>(2.0f, 10000.0f);
        inCameras[i].fov = qDegreesToRadians(90.f);
 
        inCameras[i].localTransform = QSSGRenderNode::calculateTransformMatrix(inProbePos, QSSGRenderNode::initScale, inProbePivot, rotOfs[i]);
        inCameras[i].calculateGlobalVariables(theViewport);
    }
}
 
static void setupCameraForShadowMap(const QSSGRenderCamera &inCamera,
                                    const QSSGRenderLight *inLight,
                                    QSSGRenderCamera &theCamera,
                                    const QSSGBoxPoints &castingBox,
                                    const QSSGBoxPoints &receivingBox)
{
    using namespace RenderHelpers;
 
    // setup light matrix
    quint32 mapRes = 1 << inLight->m_shadowMapRes;
    QRectF theViewport(0.0f, 0.0f, (float)mapRes, (float)mapRes);
    theCamera.clipNear = 1.0f;
    theCamera.clipFar = inLight->m_shadowMapFar;
    // Setup camera projection
    QVector3D inLightPos = inLight->getGlobalPos();
    QVector3D inLightDir = inLight->getDirection();
    QVector3D inLightPivot = inLight->pivot;
 
    inLightPos -= inLightDir * inCamera.clipNear;
    theCamera.fov = qDegreesToRadians(90.f);
    theCamera.parent = nullptr;
 
    if (inLight->type == QSSGRenderLight::Type::DirectionalLight) {
        Q_ASSERT(theCamera.type == QSSGRenderCamera::Type::OrthographicCamera);
        const QVector3D forward = inLightDir.normalized();
        const QVector3D right = qFuzzyCompare(qAbs(forward.y()), 1.0f)
                ? QVector3D::crossProduct(forward, QVector3D(1, 0, 0)).normalized()
                : QVector3D::crossProduct(forward, QVector3D(0, 1, 0)).normalized();
        const QVector3D up = QVector3D::crossProduct(right, forward).normalized();
 
        // Calculate bounding box of the scene camera frustum
        const QSSGBoxPoints frustumPoints = computeFrustumBounds(inCamera);
        const QSSGBounds3 frustumBounds = calculateShadowCameraBoundingBox(frustumPoints, forward, up, right);
        const QSSGBounds3 sceneCastingBounds = calculateShadowCameraBoundingBox(castingBox, forward, up, right);
        const QSSGBounds3 boundsReceiving = calculateShadowCameraBoundingBox(receivingBox, forward, up, right);
 
        QVector3D finalDims;
        QVector3D center;
        // Select smallest bounds from either scene or camera frustum
        if (sceneCastingBounds.isFinite() && boundsReceiving.isFinite() // handle empty scene
            && sceneCastingBounds.extents().lengthSquared() < frustumBounds.extents().lengthSquared()) {
            center = calcCenter(castingBox);
            const QVector3D centerReceiving = calcCenter(receivingBox);
 
            // Since we need to make sure every rendered geometry can get a valid depth value from the shadow map
            // we need to expand the scene bounding box along its z-axis so that it covers also receiving objects in the scene.
            //
            // We take the z dimensions of the casting bounds and expand it to include the z dimensions of the receiving objects.
            // We call the casting bounding box 'a' and the receiving bounding box 'b'.
 
            // length of boxes
            const float aLength = sceneCastingBounds.dimensions().z();
            const float bLength = boundsReceiving.dimensions().z();
 
            // center position of boxes
            const float aCenter = QVector3D::dotProduct(center, forward);
            const float bCenter = QVector3D::dotProduct(centerReceiving, forward);
 
            // distance between boxes
            const float d = bCenter - aCenter;
 
            // start/end positions
            const float a0 = 0.f;
            const float a1 = aLength;
            const float b0 = (aLength * 0.5f) + d - (bLength * 0.5f);
            const float b1 = (aLength * 0.5f) + d + (bLength * 0.5f);
 
            // goal start/end position
            const float ap0 = qMin(a0, b0);
            const float ap1 = qMax(a1, b1);
            // goal length
            const float length = ap1 - ap0;
            // goal center postion
            const float c = (ap1 + ap0) * 0.5f;
 
            // how much to move in forward direction
            const float move = c - aLength * 0.5f;
 
            center = center + forward * move;
            finalDims = sceneCastingBounds.dimensions();
            finalDims.setZ(length);
        } else {
            center = calcCenter(frustumPoints);
            finalDims = frustumBounds.dimensions();
        }
 
        // Expand dimensions a little bit to avoid precision problems
        finalDims *= 1.05f;
 
        // Apply bounding box parameters to shadow map camera projection matrix
        // so that the whole scene is fit inside the shadow map
        theViewport.setHeight(finalDims.y());
        theViewport.setWidth(finalDims.x());
        theCamera.clipNear = -0.5f * finalDims.z();
        theCamera.clipFar = 0.5f * finalDims.z();
        theCamera.localTransform = QSSGRenderNode::calculateTransformMatrix(center, QSSGRenderNode::initScale, inLightPivot, QQuaternion::fromDirection(forward, up));
    } else if (inLight->type == QSSGRenderLight::Type::PointLight) {
        theCamera.lookAt(inLightPos, QVector3D(0, 1.0, 0), QVector3D(0, 0, 0), inLightPivot);
    }
 
    theCamera.calculateGlobalVariables(theViewport);
}
 
static void addOpaqueDepthPrePassBindings(QSSGRhiContext *rhiCtx,
                                          QSSGRhiShaderPipeline *shaderPipeline,
                                          QSSGRenderableImage *renderableImage,
                                          QSSGRhiShaderResourceBindingList &bindings,
                                          bool isCustomMaterialMeshSubset = false)
{
    static const auto imageAffectsAlpha = [](QSSGRenderableImage::Type mapType) {
        return mapType == QSSGRenderableImage::Type::BaseColor ||
                mapType == QSSGRenderableImage::Type::Diffuse ||
                mapType == QSSGRenderableImage::Type::Translucency ||
                mapType == QSSGRenderableImage::Type::Opacity;
    };
 
    while (renderableImage) {
        const auto mapType = renderableImage->m_mapType;
        if (imageAffectsAlpha(mapType)) {
            const char *samplerName = QSSGMaterialShaderGenerator::getSamplerName(mapType);
            const int samplerHint = int(mapType);
            int samplerBinding = shaderPipeline->bindingForTexture(samplerName, samplerHint);
            if (samplerBinding >= 0) {
                QRhiTexture *texture = renderableImage->m_texture.m_texture;
                if (samplerBinding >= 0 && texture) {
                    const bool mipmapped = texture->flags().testFlag(QRhiTexture::MipMapped);
                    QRhiSampler *sampler = rhiCtx->sampler({ toRhi(renderableImage->m_imageNode.m_minFilterType),
                            toRhi(renderableImage->m_imageNode.m_magFilterType),
                            mipmapped ? toRhi(renderableImage->m_imageNode.m_mipFilterType) : QRhiSampler::None,
                            toRhi(renderableImage->m_imageNode.m_horizontalTilingMode),
                            toRhi(renderableImage->m_imageNode.m_verticalTilingMode),
                            QRhiSampler::Repeat
                    });
                    bindings.addTexture(samplerBinding, RENDERER_VISIBILITY_ALL, texture, sampler);
                }
            } // else this is not necessarily an error, e.g. having metalness/roughness maps with metalness disabled
        }
        renderableImage = renderableImage->m_nextImage;
    }
    // For custom Materials we can't know which maps affect alpha, so map all
    if (isCustomMaterialMeshSubset) {
        QVector<QShaderDescription::InOutVariable> samplerVars =
                shaderPipeline->fragmentStage()->shader().description().combinedImageSamplers();
        for (const QShaderDescription::InOutVariable &var : shaderPipeline->vertexStage()->shader().description().combinedImageSamplers()) {
            auto it = std::find_if(samplerVars.cbegin(), samplerVars.cend(),
                                   [&var](const QShaderDescription::InOutVariable &v) { return var.binding == v.binding; });
            if (it == samplerVars.cend())
                samplerVars.append(var);
        }
 
        int maxSamplerBinding = -1;
        for (const QShaderDescription::InOutVariable &var : samplerVars)
            maxSamplerBinding = qMax(maxSamplerBinding, var.binding);
 
        // Will need to set unused image-samplers to something dummy
        // because the shader code contains all custom property textures,
        // and not providing a binding for all of them is invalid with some
        // graphics APIs (and will need a real texture because setting a
        // null handle or similar is not permitted with some of them so the
        // srb does not accept null QRhiTextures either; but first let's
        // figure out what bindings are unused in this frame)
        QBitArray samplerBindingsSpecified(maxSamplerBinding + 1);
 
        if (maxSamplerBinding >= 0) {
            // custom property textures
            int customTexCount = shaderPipeline->extraTextureCount();
            for (int i = 0; i < customTexCount; ++i) {
                const QSSGRhiTexture &t(shaderPipeline->extraTextureAt(i));
                const int samplerBinding = shaderPipeline->bindingForTexture(t.name);
                if (samplerBinding >= 0) {
                    samplerBindingsSpecified.setBit(samplerBinding);
                    QRhiSampler *sampler = rhiCtx->sampler(t.samplerDesc);
                    bindings.addTexture(samplerBinding,
                                        RENDERER_VISIBILITY_ALL,
                                        t.texture,
                                        sampler);
                }
            }
        }
 
        // use a dummy texture for the unused samplers in the shader
        QRhiSampler *dummySampler = rhiCtx->sampler({ QRhiSampler::Nearest, QRhiSampler::Nearest, QRhiSampler::None,
                                                      QRhiSampler::ClampToEdge, QRhiSampler::ClampToEdge, QRhiSampler::Repeat });
        QRhiResourceUpdateBatch *resourceUpdates = rhiCtx->rhi()->nextResourceUpdateBatch();
        QRhiTexture *dummyTexture = rhiCtx->dummyTexture({}, resourceUpdates);
        QRhiTexture *dummyCubeTexture = rhiCtx->dummyTexture(QRhiTexture::CubeMap, resourceUpdates);
        rhiCtx->commandBuffer()->resourceUpdate(resourceUpdates);
 
        for (const QShaderDescription::InOutVariable &var : samplerVars) {
            if (!samplerBindingsSpecified.testBit(var.binding)) {
                QRhiTexture *t = var.type == QShaderDescription::SamplerCube ? dummyCubeTexture : dummyTexture;
                bindings.addTexture(var.binding, RENDERER_VISIBILITY_ALL, t, dummySampler);
            }
        }
    }
}
 
static void setupCubeShadowCameras(const QSSGRenderLight *inLight, QSSGRenderCamera inCameras[6])
{
    Q_ASSERT(inLight != nullptr);
    Q_ASSERT(inLight->type != QSSGRenderLight::Type::DirectionalLight);
 
    // setup light matrix
    quint32 mapRes = 1 << inLight->m_shadowMapRes;
    QRectF theViewport(0.0f, 0.0f, (float)mapRes, (float)mapRes);
    static const QQuaternion rotOfs[6] {
                                         QQuaternion::fromEulerAngles(0.f, qRadiansToDegrees(-QSSG_HALFPI), qRadiansToDegrees(QSSG_PI)),
                                         QQuaternion::fromEulerAngles(0.f, qRadiansToDegrees(QSSG_HALFPI), qRadiansToDegrees(QSSG_PI)),
                                         QQuaternion::fromEulerAngles(qRadiansToDegrees(QSSG_HALFPI), 0.f, 0.f),
                                         QQuaternion::fromEulerAngles(qRadiansToDegrees(-QSSG_HALFPI), 0.f, 0.f),
                                         QQuaternion::fromEulerAngles(0.f, qRadiansToDegrees(QSSG_PI), qRadiansToDegrees(-QSSG_PI)),
                                         QQuaternion::fromEulerAngles(0.f, 0.f, qRadiansToDegrees(QSSG_PI)),
                                         };
 
    const QVector3D inLightPos = inLight->getGlobalPos();
    const QVector3D inLightPivot = inLight->pivot;
 
    for (int i = 0; i < 6; ++i) {
        inCameras[i].parent = nullptr;
        inCameras[i].clipNear = 1.0f;
        inCameras[i].clipFar = qMax<float>(2.0f, inLight->m_shadowMapFar);
        inCameras[i].fov = qDegreesToRadians(90.f);
        inCameras[i].localTransform = QSSGRenderNode::calculateTransformMatrix(inLightPos, QSSGRenderNode::initScale, inLightPivot, rotOfs[i]);
        inCameras[i].calculateGlobalVariables(theViewport);
    }
 
    /*
        if ( inLight->type == RenderLightTypes::Point ) return;
 
    QVector3D viewDirs[6];
    QVector3D viewUp[6];
    QMatrix3x3 theDirMatrix( inLight->m_GlobalTransform.getUpper3x3() );
 
    viewDirs[0] = theDirMatrix.transform( QVector3D( 1.f, 0.f, 0.f ) );
    viewDirs[2] = theDirMatrix.transform( QVector3D( 0.f, -1.f, 0.f ) );
    viewDirs[4] = theDirMatrix.transform( QVector3D( 0.f, 0.f, 1.f ) );
    viewDirs[0].normalize();  viewDirs[2].normalize();  viewDirs[4].normalize();
    viewDirs[1] = -viewDirs[0];
    viewDirs[3] = -viewDirs[2];
    viewDirs[5] = -viewDirs[4];
 
    viewUp[0] = viewDirs[2];
    viewUp[1] = viewDirs[2];
    viewUp[2] = viewDirs[5];
    viewUp[3] = viewDirs[4];
    viewUp[4] = viewDirs[2];
    viewUp[5] = viewDirs[2];
 
    for (int i = 0; i < 6; ++i)
    {
        inCameras[i].LookAt( inLightPos, viewUp[i], inLightPos + viewDirs[i] );
        inCameras[i].CalculateGlobalVariables( theViewport, QVector2D( theViewport.m_Width,
                                                                     theViewport.m_Height ) );
    }
    */
}
 
static int setupInstancing(QSSGSubsetRenderable *renderable, QSSGRhiGraphicsPipelineState *ps, QSSGRhiContext *rhiCtx, const QVector3D &cameraDirection, const QVector3D &cameraPosition)
{
    // TODO: non-static so it can be used from QSSGCustomMaterialSystem::rhiPrepareRenderable()?
    const bool instancing = renderable->prepareInstancing(rhiCtx, cameraDirection, cameraPosition, renderable->instancingLodMin, renderable->instancingLodMax);
    int instanceBufferBinding = 0;
    if (instancing) {
        // set up new bindings for instanced buffers
        const quint32 stride = renderable->modelContext.model.instanceTable->stride();
        QVarLengthArray<QRhiVertexInputBinding, 8> bindings;
        std::copy(ps->ia.inputLayout.cbeginBindings(), ps->ia.inputLayout.cendBindings(), std::back_inserter(bindings));
        bindings.append({ stride, QRhiVertexInputBinding::PerInstance });
        instanceBufferBinding = bindings.size() - 1;
        ps->ia.inputLayout.setBindings(bindings.cbegin(), bindings.cend());
    }
    return instanceBufferBinding;
}
 
static void rhiPrepareResourcesForReflectionMap(QSSGRhiContext *rhiCtx,
                                                QSSGPassKey passKey,
                                                const QSSGLayerRenderData &inData,
                                                QSSGReflectionMapEntry *pEntry,
                                                QSSGRhiGraphicsPipelineState *ps,
                                                const QVector<QSSGRenderableObjectHandle> &sortedOpaqueObjects,
                                                QSSGRenderCamera &inCamera,
                                                QSSGRenderer &renderer,
                                                int cubeFace)
{
    using namespace RenderHelpers;
 
    if ((inData.layer.background == QSSGRenderLayer::Background::SkyBox && inData.layer.lightProbe) ||
         inData.layer.background == QSSGRenderLayer::Background::SkyBoxCubeMap)
        rhiPrepareSkyBoxForReflectionMap(rhiCtx, passKey, inData.layer, inCamera, renderer, pEntry, cubeFace);
 
    QSSGShaderFeatures features = inData.getShaderFeatures();
 
    for (const auto &handle : sortedOpaqueObjects) {
        QSSGRenderableObject &inObject = *handle.obj;
 
        QMatrix4x4 modelViewProjection;
        if (inObject.type == QSSGRenderableObject::Type::DefaultMaterialMeshSubset || inObject.type == QSSGRenderableObject::Type::CustomMaterialMeshSubset) {
            QSSGSubsetRenderable &renderable(static_cast<QSSGSubsetRenderable &>(inObject));
            const bool hasSkinning = renderer.defaultMaterialShaderKeyProperties().m_boneCount.getValue(renderable.shaderDescription) > 0;
            modelViewProjection = hasSkinning ? pEntry->m_viewProjection
                                              : pEntry->m_viewProjection * renderable.globalTransform;
        }
 
        rhiPrepareRenderable(rhiCtx, passKey, inData, inObject, pEntry->m_rhiRenderPassDesc, ps, features, 1,
                             &inCamera, &modelViewProjection, cubeFace, pEntry);
    }
}
 
static inline void addDepthTextureBindings(QSSGRhiContext *rhiCtx,
                                           QSSGRhiShaderPipeline *shaderPipeline,
                                           QSSGRhiShaderResourceBindingList &bindings)
{
    if (shaderPipeline->depthTexture()) {
        int binding = shaderPipeline->bindingForTexture("qt_depthTexture", int(QSSGRhiSamplerBindingHints::DepthTexture));
        if (binding >= 0) {
            // nearest min/mag, no mipmap
            QRhiSampler *sampler = rhiCtx->sampler({ QRhiSampler::Nearest, QRhiSampler::Nearest, QRhiSampler::None,
                                                     QRhiSampler::ClampToEdge, QRhiSampler::ClampToEdge, QRhiSampler::Repeat });
            bindings.addTexture(binding, QRhiShaderResourceBinding::FragmentStage, shaderPipeline->depthTexture(), sampler);
        } // else ignore, not an error
    }
 
    // SSAO texture
    if (shaderPipeline->ssaoTexture()) {
        int binding = shaderPipeline->bindingForTexture("qt_aoTexture", int(QSSGRhiSamplerBindingHints::AoTexture));
        if (binding >= 0) {
            // linear min/mag, no mipmap
            QRhiSampler *sampler = rhiCtx->sampler({ QRhiSampler::Linear, QRhiSampler::Linear, QRhiSampler::None,
                                                     QRhiSampler::ClampToEdge, QRhiSampler::ClampToEdge, QRhiSampler::Repeat });
            bindings.addTexture(binding, QRhiShaderResourceBinding::FragmentStage, shaderPipeline->ssaoTexture(), sampler);
        } // else ignore, not an error
    }
}
 
static void rhiPrepareResourcesForShadowMap(QSSGRhiContext *rhiCtx,
                                            const QSSGLayerRenderData &inData,
                                            QSSGPassKey passKey,
                                            const QSSGLayerGlobalRenderProperties &globalRenderProperties,
                                            QSSGShadowMapEntry *pEntry,
                                            QSSGRhiGraphicsPipelineState *ps,
                                            const QVector2D *depthAdjust,
                                            const QVector<QSSGRenderableObjectHandle> &sortedOpaqueObjects,
                                            QSSGRenderCamera &inCamera,
                                            bool orthographic,
                                            int cubeFace)
{
    QSSGShaderFeatures featureSet;
    if (orthographic)
        featureSet.set(QSSGShaderFeatures::Feature::OrthoShadowPass, true);
    else
        featureSet.set(QSSGShaderFeatures::Feature::CubeShadowPass, true);
 
    for (const auto &handle : sortedOpaqueObjects) {
        QSSGRenderableObject *theObject = handle.obj;
        QSSG_ASSERT(theObject->renderableFlags.castsShadows(), continue);
 
        QSSGShaderFeatures objectFeatureSet = featureSet;
        const bool isOpaqueDepthPrePass = theObject->depthWriteMode == QSSGDepthDrawMode::OpaquePrePass;
        if (isOpaqueDepthPrePass)
            objectFeatureSet.set(QSSGShaderFeatures::Feature::OpaqueDepthPrePass, true);
 
        QSSGRhiDrawCallData *dcd = nullptr;
        QMatrix4x4 modelViewProjection;
        QSSGSubsetRenderable &renderable(static_cast<QSSGSubsetRenderable &>(*theObject));
        const auto &renderer(renderable.renderer);
        if (theObject->type == QSSGRenderableObject::Type::DefaultMaterialMeshSubset || theObject->type == QSSGRenderableObject::Type::CustomMaterialMeshSubset) {
            const bool hasSkinning = renderer->defaultMaterialShaderKeyProperties().m_boneCount.getValue(renderable.shaderDescription) > 0;
            modelViewProjection = hasSkinning ? pEntry->m_lightVP
                                              : pEntry->m_lightVP * renderable.globalTransform;
            dcd = &rhiCtx->drawCallData({ passKey, &renderable.modelContext.model,
                                          pEntry, cubeFace + int(renderable.subset.offset << 3), QSSGRhiDrawCallDataKey::Shadow });
        }
 
        QSSGRhiShaderResourceBindingList bindings;
        QSSGRhiShaderPipelinePtr shaderPipeline;
        QSSGSubsetRenderable &subsetRenderable(static_cast<QSSGSubsetRenderable &>(*theObject));
        if (theObject->type == QSSGSubsetRenderable::Type::DefaultMaterialMeshSubset) {
            ps->cullMode = QSSGRhiGraphicsPipelineState::toCullMode(subsetRenderable.defaultMaterial().cullMode);
            const bool blendParticles = subsetRenderable.renderer->defaultMaterialShaderKeyProperties().m_blendParticles.getValue(subsetRenderable.shaderDescription);
 
            shaderPipeline = shadersForDefaultMaterial(ps, subsetRenderable, objectFeatureSet);
            if (!shaderPipeline)
                continue;
            shaderPipeline->ensureCombinedMainLightsUniformBuffer(&dcd->ubuf);
            char *ubufData = dcd->ubuf->beginFullDynamicBufferUpdateForCurrentFrame();
            updateUniformsForDefaultMaterial(*shaderPipeline, rhiCtx, inData, ubufData, ps, subsetRenderable, inCamera, depthAdjust, &modelViewProjection);
            if (blendParticles)
                QSSGParticleRenderer::updateUniformsForParticleModel(*shaderPipeline, ubufData, &subsetRenderable.modelContext.model, subsetRenderable.subset.offset);
            dcd->ubuf->endFullDynamicBufferUpdateForCurrentFrame();
            if (blendParticles)
                QSSGParticleRenderer::prepareParticlesForModel(*shaderPipeline, rhiCtx, bindings, &subsetRenderable.modelContext.model);
        } else if (theObject->type == QSSGSubsetRenderable::Type::CustomMaterialMeshSubset) {
            ps->cullMode = QSSGRhiGraphicsPipelineState::toCullMode(subsetRenderable.customMaterial().m_cullMode);
 
            QSSGCustomMaterialSystem &customMaterialSystem(*subsetRenderable.renderer->contextInterface()->customMaterialSystem().get());
            shaderPipeline = customMaterialSystem.shadersForCustomMaterial(ps, subsetRenderable.customMaterial(), subsetRenderable, objectFeatureSet);
            if (!shaderPipeline)
                continue;
            shaderPipeline->ensureCombinedMainLightsUniformBuffer(&dcd->ubuf);
            char *ubufData = dcd->ubuf->beginFullDynamicBufferUpdateForCurrentFrame();
            // inCamera is the shadow camera, not the same as inData.camera
            customMaterialSystem.updateUniformsForCustomMaterial(*shaderPipeline, rhiCtx, inData, ubufData, ps, subsetRenderable.customMaterial(), subsetRenderable,
                                                                 inCamera, depthAdjust, &modelViewProjection);
            dcd->ubuf->endFullDynamicBufferUpdateForCurrentFrame();
        }
 
        if (theObject->type == QSSGRenderableObject::Type::DefaultMaterialMeshSubset || theObject->type == QSSGRenderableObject::Type::CustomMaterialMeshSubset) {
 
            ps->shaderPipeline = shaderPipeline.get();
            ps->ia = subsetRenderable.subset.rhi.ia;
            int instanceBufferBinding = setupInstancing(&subsetRenderable, ps, rhiCtx, globalRenderProperties.cameraData.direction, globalRenderProperties.cameraData.position);
            ps->ia.bakeVertexInputLocations(*shaderPipeline, instanceBufferBinding);
 
 
            bindings.addUniformBuffer(0, RENDERER_VISIBILITY_ALL, dcd->ubuf);
 
                 // Depth and SSAO textures, in case a custom material's shader code does something with them.
            addDepthTextureBindings(rhiCtx, shaderPipeline.get(), bindings);
 
            if (isOpaqueDepthPrePass) {
                addOpaqueDepthPrePassBindings(rhiCtx,
                                              shaderPipeline.get(),
                                              subsetRenderable.firstImage,
                                              bindings,
                                              (theObject->type == QSSGRenderableObject::Type::CustomMaterialMeshSubset));
            }
 
            // There is no screen texture at this stage. But the shader from a
            // custom material may rely on it, and an object with that material
            // can end up in the shadow map's object list. So bind a dummy
            // texture then due to the lack of other options.
            int binding = shaderPipeline->bindingForTexture("qt_screenTexture", int(QSSGRhiSamplerBindingHints::ScreenTexture));
            if (binding >= 0) {
                QRhiSampler *sampler = rhiCtx->sampler({ QRhiSampler::Nearest, QRhiSampler::Nearest, QRhiSampler::None,
                                                         QRhiSampler::Repeat, QRhiSampler::Repeat, QRhiSampler::Repeat });
                QRhiResourceUpdateBatch *resourceUpdates = rhiCtx->rhi()->nextResourceUpdateBatch();
                QRhiTexture *dummyTexture = rhiCtx->dummyTexture({}, resourceUpdates);
                rhiCtx->commandBuffer()->resourceUpdate(resourceUpdates);
                bindings.addTexture(binding,
                                    QRhiShaderResourceBinding::FragmentStage,
                                    dummyTexture, sampler);
            }
 
            QRhiShaderResourceBindings *srb = rhiCtx->srb(bindings);
            subsetRenderable.rhiRenderData.shadowPass.pipeline = rhiCtx->pipeline(QSSGGraphicsPipelineStateKey::create(*ps, pEntry->m_rhiRenderPassDesc, srb),
                                                                                  pEntry->m_rhiRenderPassDesc,
                                                                                  srb);
            subsetRenderable.rhiRenderData.shadowPass.srb[cubeFace] = srb;
        }
    }
}
 
static void fillTargetBlend(QRhiGraphicsPipeline::TargetBlend *targetBlend, QSSGRenderDefaultMaterial::MaterialBlendMode materialBlend)
{
    // Assuming default values in the other TargetBlend fields
    switch (materialBlend) {
    case QSSGRenderDefaultMaterial::MaterialBlendMode::Screen:
        targetBlend->srcColor = QRhiGraphicsPipeline::SrcAlpha;
        targetBlend->dstColor = QRhiGraphicsPipeline::One;
        targetBlend->srcAlpha = QRhiGraphicsPipeline::One;
        targetBlend->dstAlpha = QRhiGraphicsPipeline::One;
        break;
    case QSSGRenderDefaultMaterial::MaterialBlendMode::Multiply:
        targetBlend->srcColor = QRhiGraphicsPipeline::DstColor;
        targetBlend->dstColor = QRhiGraphicsPipeline::Zero;
        targetBlend->srcAlpha = QRhiGraphicsPipeline::One;
        targetBlend->dstAlpha = QRhiGraphicsPipeline::One;
        break;
    default:
        // Use SourceOver for everything else
        targetBlend->srcColor = QRhiGraphicsPipeline::SrcAlpha;
        targetBlend->dstColor = QRhiGraphicsPipeline::OneMinusSrcAlpha;
        targetBlend->srcAlpha = QRhiGraphicsPipeline::One;
        targetBlend->dstAlpha = QRhiGraphicsPipeline::OneMinusSrcAlpha;
        break;
    }
}
 
void RenderHelpers::rhiPrepareRenderable(QSSGRhiContext *rhiCtx,
                                         QSSGPassKey passKey,
                                         const QSSGLayerRenderData &inData,
                                         QSSGRenderableObject &inObject,
                                         QRhiRenderPassDescriptor *renderPassDescriptor,
                                         QSSGRhiGraphicsPipelineState *ps,
                                         QSSGShaderFeatures featureSet,
                                         int samples,
                                         QSSGRenderCamera *inCamera,
                                         QMatrix4x4 *alteredModelViewProjection,
                                         int cubeFace,
                                         QSSGReflectionMapEntry *entry)
{
    QSSGRenderCamera *camera = inData.camera;
    if (inCamera)
        camera = inCamera;
 
    switch (inObject.type) {
    case QSSGRenderableObject::Type::DefaultMaterialMeshSubset:
    {
        QSSGSubsetRenderable &subsetRenderable(static_cast<QSSGSubsetRenderable &>(inObject));
 
        if (cubeFace < 0 && subsetRenderable.reflectionProbeIndex >= 0 && subsetRenderable.renderableFlags.testFlag(QSSGRenderableObjectFlag::ReceivesReflections))
            featureSet.set(QSSGShaderFeatures::Feature::ReflectionProbe, true);
 
        if (cubeFace >= 0) {
            // Disable tonemapping for the reflection pass
            featureSet.disableTonemapping();
        }
 
        if (subsetRenderable.renderableFlags.rendersWithLightmap())
            featureSet.set(QSSGShaderFeatures::Feature::Lightmap, true);
 
        const auto &shaderPipeline = shadersForDefaultMaterial(ps, subsetRenderable, featureSet);
        if (shaderPipeline) {
            // Unlike the subsetRenderable (which is allocated per frame so is
            // not persistent in any way), the model reference is persistent in
            // the sense that it references the model node in the scene graph.
            // Combined with the layer node (multiple View3Ds may share the
            // same scene!), this is suitable as a key to get the uniform
            // buffers that were used with the rendering of the same model in
            // the previous frame.
            QSSGRhiShaderResourceBindingList bindings;
            const auto &modelNode = subsetRenderable.modelContext.model;
            const bool blendParticles = subsetRenderable.renderer->defaultMaterialShaderKeyProperties().m_blendParticles.getValue(subsetRenderable.shaderDescription);
 
            QSSGRhiDrawCallData &dcd(cubeFace >= 0 ? rhiCtx->drawCallData({ passKey, &modelNode,
                                                                            entry, cubeFace + int(subsetRenderable.subset.offset << 3),
                                                                            QSSGRhiDrawCallDataKey::Reflection })
                                                   : rhiCtx->drawCallData({ passKey, &modelNode,
                                                                            &subsetRenderable.material, 0, QSSGRhiDrawCallDataKey::Main }));
 
            shaderPipeline->ensureCombinedMainLightsUniformBuffer(&dcd.ubuf);
            char *ubufData = dcd.ubuf->beginFullDynamicBufferUpdateForCurrentFrame();
            updateUniformsForDefaultMaterial(*shaderPipeline, rhiCtx, inData, ubufData, ps, subsetRenderable, *camera, nullptr, alteredModelViewProjection);
            if (blendParticles)
                QSSGParticleRenderer::updateUniformsForParticleModel(*shaderPipeline, ubufData, &subsetRenderable.modelContext.model, subsetRenderable.subset.offset);
            dcd.ubuf->endFullDynamicBufferUpdateForCurrentFrame();
 
            if (blendParticles)
                QSSGParticleRenderer::prepareParticlesForModel(*shaderPipeline, rhiCtx, bindings, &subsetRenderable.modelContext.model);
 
            // Skinning
            if (QRhiTexture *boneTexture = inData.getBonemapTexture(subsetRenderable.modelContext)) {
                int binding = shaderPipeline->bindingForTexture("qt_boneTexture");
                if (binding >= 0) {
                    QRhiSampler *boneSampler = rhiCtx->sampler({ QRhiSampler::Nearest,
                            QRhiSampler::Nearest,
                            QRhiSampler::None,
                            QRhiSampler::ClampToEdge,
                            QRhiSampler::ClampToEdge,
                            QRhiSampler::Repeat
                    });
                    bindings.addTexture(binding,
                                        QRhiShaderResourceBinding::VertexStage,
                                        boneTexture,
                                        boneSampler);
                }
            }
            // Morphing
            auto *targetsTexture = subsetRenderable.subset.rhi.targetsTexture;
            if (targetsTexture) {
                int binding = shaderPipeline->bindingForTexture("qt_morphTargetTexture");
                if (binding >= 0) {
                    QRhiSampler *targetsSampler = rhiCtx->sampler({ QRhiSampler::Nearest,
                                                                    QRhiSampler::Nearest,
                                                                    QRhiSampler::None,
                                                                    QRhiSampler::ClampToEdge,
                                                                    QRhiSampler::ClampToEdge,
                                                                    QRhiSampler::ClampToEdge
                                                               });
                    bindings.addTexture(binding, QRhiShaderResourceBinding::VertexStage, subsetRenderable.subset.rhi.targetsTexture, targetsSampler);
                }
            }
 
            ps->samples = samples;
 
            ps->cullMode = QSSGRhiGraphicsPipelineState::toCullMode(subsetRenderable.defaultMaterial().cullMode);
            fillTargetBlend(&ps->targetBlend, subsetRenderable.defaultMaterial().blendMode);
 
            ps->ia = subsetRenderable.subset.rhi.ia;
            QVector3D cameraDirection = inData.cameraData->direction;
            if (inCamera)
                cameraDirection = inCamera->getScalingCorrectDirection();
            QVector3D cameraPosition = inData.cameraData->position;
            if (inCamera)
                cameraPosition = inCamera->getGlobalPos();
            int instanceBufferBinding = setupInstancing(&subsetRenderable, ps, rhiCtx, cameraDirection, cameraPosition);
            ps->ia.bakeVertexInputLocations(*shaderPipeline, instanceBufferBinding);
 
            bindings.addUniformBuffer(0, RENDERER_VISIBILITY_ALL, dcd.ubuf, 0, shaderPipeline->ub0Size());
 
            if (shaderPipeline->isLightingEnabled()) {
                bindings.addUniformBuffer(1, RENDERER_VISIBILITY_ALL, dcd.ubuf,
                                          shaderPipeline->ub0LightDataOffset(),
                                          shaderPipeline->ub0LightDataSize());
            }
 
            // Texture maps
            QSSGRenderableImage *renderableImage = subsetRenderable.firstImage;
            while (renderableImage) {
                const char *samplerName = QSSGMaterialShaderGenerator::getSamplerName(renderableImage->m_mapType);
                const int samplerHint = int(renderableImage->m_mapType);
                int samplerBinding = shaderPipeline->bindingForTexture(samplerName, samplerHint);
                if (samplerBinding >= 0) {
                    QRhiTexture *texture = renderableImage->m_texture.m_texture;
                    if (samplerBinding >= 0 && texture) {
                        const bool mipmapped = texture->flags().testFlag(QRhiTexture::MipMapped);
                        QSSGRhiSamplerDescription samplerDesc = {
                            toRhi(renderableImage->m_imageNode.m_minFilterType),
                            toRhi(renderableImage->m_imageNode.m_magFilterType),
                            mipmapped ? toRhi(renderableImage->m_imageNode.m_mipFilterType) : QRhiSampler::None,
                            toRhi(renderableImage->m_imageNode.m_horizontalTilingMode),
                            toRhi(renderableImage->m_imageNode.m_verticalTilingMode),
                            QRhiSampler::Repeat
                        };
                        rhiCtx->checkAndAdjustForNPoT(texture, &samplerDesc);
                        QRhiSampler *sampler = rhiCtx->sampler(samplerDesc);
                        bindings.addTexture(samplerBinding, RENDERER_VISIBILITY_ALL, texture, sampler);
                    }
                } // else this is not necessarily an error, e.g. having metalness/roughness maps with metalness disabled
                renderableImage = renderableImage->m_nextImage;
            }
 
            if (shaderPipeline->isLightingEnabled()) {
                // Shadow map textures
                const int shadowMapCount = shaderPipeline->shadowMapCount();
                for (int i = 0; i < shadowMapCount; ++i) {
                    QSSGRhiShadowMapProperties &shadowMapProperties(shaderPipeline->shadowMapAt(i));
                    QRhiTexture *texture = shadowMapProperties.shadowMapTexture;
                    QRhiSampler *sampler = rhiCtx->sampler({ QRhiSampler::Linear, QRhiSampler::Linear, QRhiSampler::None,
                                                             QRhiSampler::ClampToEdge, QRhiSampler::ClampToEdge, QRhiSampler::Repeat });
                    Q_ASSERT(texture && sampler);
                    const QByteArray &name(shadowMapProperties.shadowMapTextureUniformName);
                    if (shadowMapProperties.cachedBinding < 0)
                        shadowMapProperties.cachedBinding = shaderPipeline->bindingForTexture(name);
                    if (shadowMapProperties.cachedBinding < 0) {
                        qWarning("No combined image sampler for shadow map texture '%s'", name.data());
                        continue;
                    }
                    bindings.addTexture(shadowMapProperties.cachedBinding, QRhiShaderResourceBinding::FragmentStage,
                                        texture, sampler);
                }
 
                 // Prioritize reflection texture over Light Probe texture because
                 // reflection texture also contains the irradiance and pre filtered
                 // values for the light probe.
                if (featureSet.isSet(QSSGShaderFeatures::Feature::ReflectionProbe)) {
                    int reflectionSampler = shaderPipeline->bindingForTexture("qt_reflectionMap");
                    QRhiSampler *sampler = rhiCtx->sampler({ QRhiSampler::Linear, QRhiSampler::Linear, QRhiSampler::Linear,
                                                             QRhiSampler::ClampToEdge, QRhiSampler::ClampToEdge, QRhiSampler::Repeat });
                    QRhiTexture* reflectionTexture = inData.getReflectionMapManager()->reflectionMapEntry(subsetRenderable.reflectionProbeIndex)->m_rhiPrefilteredCube;
                    if (reflectionSampler >= 0 && reflectionTexture)
                        bindings.addTexture(reflectionSampler, QRhiShaderResourceBinding::FragmentStage, reflectionTexture, sampler);
                } else if (shaderPipeline->lightProbeTexture()) {
                    int binding = shaderPipeline->bindingForTexture("qt_lightProbe", int(QSSGRhiSamplerBindingHints::LightProbe));
                    if (binding >= 0) {
                        auto tiling = shaderPipeline->lightProbeTiling();
                        QRhiSampler *sampler = rhiCtx->sampler({ QRhiSampler::Linear, QRhiSampler::Linear, QRhiSampler::Linear, // enables mipmapping
                                                                 toRhi(tiling.first), toRhi(tiling.second), QRhiSampler::Repeat });
                        bindings.addTexture(binding, QRhiShaderResourceBinding::FragmentStage,
                                            shaderPipeline->lightProbeTexture(), sampler);
                    } else {
                        qWarning("Could not find sampler for lightprobe");
                    }
                }
 
                // Screen Texture
                if (shaderPipeline->screenTexture()) {
                    int binding = shaderPipeline->bindingForTexture("qt_screenTexture", int(QSSGRhiSamplerBindingHints::ScreenTexture));
                    if (binding >= 0) {
                        // linear min/mag, mipmap filtering depends on the
                        // texture, with SCREEN_TEXTURE there are no mipmaps, but
                        // once SCREEN_MIP_TEXTURE is seen the texture (the same
                        // one) has mipmaps generated.
                        QRhiSampler::Filter mipFilter = shaderPipeline->screenTexture()->flags().testFlag(QRhiTexture::MipMapped)
                                ? QRhiSampler::Linear : QRhiSampler::None;
                        QRhiSampler *sampler = rhiCtx->sampler({ QRhiSampler::Linear, QRhiSampler::Linear, mipFilter,
                                                                 QRhiSampler::Repeat, QRhiSampler::Repeat, QRhiSampler::Repeat });
                        bindings.addTexture(binding,
                                            QRhiShaderResourceBinding::FragmentStage,
                                            shaderPipeline->screenTexture(), sampler);
                    } // else ignore, not an error
                }
 
                if (shaderPipeline->lightmapTexture()) {
                    int binding = shaderPipeline->bindingForTexture("qt_lightmap", int(QSSGRhiSamplerBindingHints::LightmapTexture));
                    if (binding >= 0) {
                        QRhiSampler *sampler = rhiCtx->sampler({ QRhiSampler::Linear, QRhiSampler::Linear, QRhiSampler::None,
                                                                 QRhiSampler::ClampToEdge, QRhiSampler::ClampToEdge, QRhiSampler::Repeat });
                        bindings.addTexture(binding,
                                            QRhiShaderResourceBinding::FragmentStage,
                                            shaderPipeline->lightmapTexture(), sampler);
                    } // else ignore, not an error
                }
            }
 
            // Depth and SSAO textures
            addDepthTextureBindings(rhiCtx, shaderPipeline.get(), bindings);
 
            // Instead of always doing a QHash find in srb(), store the binding
            // list and the srb object in the per-model+material
            // QSSGRhiUniformBufferSet. While this still needs comparing the
            // binding list, to see if something has changed, it results in
            // significant gains with lots of models in the scene (because the
            // srb hash table becomes large then, so avoiding the lookup as
            // much as possible is helpful)
            QRhiShaderResourceBindings *&srb = dcd.srb;
            bool srbChanged = false;
            if (!srb || bindings != dcd.bindings) {
                srb = rhiCtx->srb(bindings);
                dcd.bindings = bindings;
                srbChanged = true;
            }
 
            if (cubeFace >= 0)
                subsetRenderable.rhiRenderData.reflectionPass.srb[cubeFace] = srb;
            else
                subsetRenderable.rhiRenderData.mainPass.srb = srb;
 
            const QSSGGraphicsPipelineStateKey pipelineKey = QSSGGraphicsPipelineStateKey::create(*ps, renderPassDescriptor, srb);
            if (dcd.pipeline
                && !srbChanged
                && dcd.renderTargetDescriptionHash == pipelineKey.extra.renderTargetDescriptionHash // we have the hash code anyway, use it to early out upon mismatch
                && dcd.renderTargetDescription == pipelineKey.renderTargetDescription
                && dcd.ps == *ps)
            {
                if (cubeFace >= 0)
                    subsetRenderable.rhiRenderData.reflectionPass.pipeline = dcd.pipeline;
                else
                    subsetRenderable.rhiRenderData.mainPass.pipeline = dcd.pipeline;
            } else {
                if (cubeFace >= 0) {
                    subsetRenderable.rhiRenderData.reflectionPass.pipeline = rhiCtx->pipeline(pipelineKey,
                                                                                              renderPassDescriptor,
                                                                                              srb);
                    dcd.pipeline = subsetRenderable.rhiRenderData.reflectionPass.pipeline;
                } else {
                    subsetRenderable.rhiRenderData.mainPass.pipeline = rhiCtx->pipeline(pipelineKey,
                                                                                        renderPassDescriptor,
                                                                                        srb);
                    dcd.pipeline = subsetRenderable.rhiRenderData.mainPass.pipeline;
                }
                dcd.renderTargetDescriptionHash = pipelineKey.extra.renderTargetDescriptionHash;
                dcd.renderTargetDescription = pipelineKey.renderTargetDescription;
                dcd.ps = *ps;
            }
        }
        break;
    }
    case QSSGRenderableObject::Type::CustomMaterialMeshSubset:
    {
        QSSGSubsetRenderable &subsetRenderable(static_cast<QSSGSubsetRenderable &>(inObject));
        const QSSGRenderCustomMaterial &material(subsetRenderable.customMaterial());
        QSSGCustomMaterialSystem &customMaterialSystem(*subsetRenderable.renderer->contextInterface()->customMaterialSystem().get());
 
        featureSet.set(QSSGShaderFeatures::Feature::LightProbe, inData.layer.lightProbe || material.m_iblProbe);
 
        if (cubeFace < 0 && subsetRenderable.reflectionProbeIndex >= 0 && subsetRenderable.renderableFlags.testFlag(QSSGRenderableObjectFlag::ReceivesReflections))
            featureSet.set(QSSGShaderFeatures::Feature::ReflectionProbe, true);
 
        if (cubeFace >= 0) {
            // Disable tonemapping for the reflection pass
            featureSet.disableTonemapping();
        }
 
        if (subsetRenderable.renderableFlags.rendersWithLightmap())
            featureSet.set(QSSGShaderFeatures::Feature::Lightmap, true);
 
        customMaterialSystem.rhiPrepareRenderable(ps, passKey, subsetRenderable, featureSet,
                                                  material, inData, renderPassDescriptor, samples,
                                                  inCamera, cubeFace, alteredModelViewProjection, entry);
        break;
    }
    case QSSGRenderableObject::Type::Particles:
    {
        QSSGParticlesRenderable &particleRenderable(static_cast<QSSGParticlesRenderable &>(inObject));
        const auto &shaderPipeline = shadersForParticleMaterial(ps, particleRenderable);
        if (shaderPipeline) {
            QSSGParticleRenderer::rhiPrepareRenderable(*shaderPipeline, passKey, rhiCtx, ps, particleRenderable, inData, renderPassDescriptor, samples,
                                                       inCamera, cubeFace, entry);
        }
        break;
    }
    }
}
 
void RenderHelpers::rhiRenderRenderable(QSSGRhiContext *rhiCtx,
                                        const QSSGRhiGraphicsPipelineState &state,
                                        QSSGRenderableObject &object,
                                        bool *needsSetViewport,
                                        int cubeFace)
{
    switch (object.type) {
    case QSSGRenderableObject::Type::DefaultMaterialMeshSubset:
    {
        QSSGSubsetRenderable &subsetRenderable(static_cast<QSSGSubsetRenderable &>(object));
 
        QRhiGraphicsPipeline *ps = subsetRenderable.rhiRenderData.mainPass.pipeline;
        QRhiShaderResourceBindings *srb = subsetRenderable.rhiRenderData.mainPass.srb;
 
        if (cubeFace >= 0) {
            ps = subsetRenderable.rhiRenderData.reflectionPass.pipeline;
            srb = subsetRenderable.rhiRenderData.reflectionPass.srb[cubeFace];
        }
 
        if (!ps || !srb)
            return;
 
        QRhiBuffer *vertexBuffer = subsetRenderable.subset.rhi.vertexBuffer->buffer();
        QRhiBuffer *indexBuffer = subsetRenderable.subset.rhi.indexBuffer ? subsetRenderable.subset.rhi.indexBuffer->buffer() : nullptr;
 
        QRhiCommandBuffer *cb = rhiCtx->commandBuffer();
        // QRhi optimizes out unnecessary binding of the same pipline
        cb->setGraphicsPipeline(ps);
        cb->setShaderResources(srb);
 
        if (*needsSetViewport) {
            cb->setViewport(state.viewport);
            if (state.scissorEnable)
                cb->setScissor(state.scissor);
            *needsSetViewport = false;
        }
 
        QRhiCommandBuffer::VertexInput vertexBuffers[2];
        int vertexBufferCount = 1;
        vertexBuffers[0] = QRhiCommandBuffer::VertexInput(vertexBuffer, 0);
        quint32 instances = 1;
        if ( subsetRenderable.modelContext.model.instancing()) {
            instances = subsetRenderable.modelContext.model.instanceCount();
            // If the instance count is 0, the bail out before trying to do any
            // draw calls. Making an instanced draw call with a count of 0 is invalid
            // for Metal and likely other API's as well.
            // It is possible that the particale system may produce 0 instances here
            if (instances == 0)
                return;
            vertexBuffers[1] = QRhiCommandBuffer::VertexInput(subsetRenderable.instanceBuffer, 0);
            vertexBufferCount = 2;
        }
        Q_QUICK3D_PROFILE_START(QQuick3DProfiler::Quick3DRenderCall);
        if (state.usesStencilRef)
            cb->setStencilRef(state.stencilRef);
        if (indexBuffer) {
            cb->setVertexInput(0, vertexBufferCount, vertexBuffers, indexBuffer, 0, subsetRenderable.subset.rhi.indexBuffer->indexFormat());
            cb->drawIndexed(subsetRenderable.subset.lodCount(subsetRenderable.subsetLevelOfDetail), instances, subsetRenderable.subset.lodOffset(subsetRenderable.subsetLevelOfDetail));
            QSSGRHICTX_STAT(rhiCtx, drawIndexed(subsetRenderable.subset.lodCount(subsetRenderable.subsetLevelOfDetail), instances));
        } else {
            cb->setVertexInput(0, vertexBufferCount, vertexBuffers);
            cb->draw(subsetRenderable.subset.count, instances, subsetRenderable.subset.offset);
            QSSGRHICTX_STAT(rhiCtx, draw(subsetRenderable.subset.count, instances));
        }
        Q_QUICK3D_PROFILE_END_WITH_IDS(QQuick3DProfiler::Quick3DRenderCall, (subsetRenderable.subset.count | quint64(instances) << 32),
                                         QVector<int>({subsetRenderable.modelContext.model.profilingId,
                                          subsetRenderable.material.profilingId}));
        break;
    }
    case QSSGRenderableObject::Type::CustomMaterialMeshSubset:
    {
        QSSGSubsetRenderable &subsetRenderable(static_cast<QSSGSubsetRenderable &>(object));
        QSSGCustomMaterialSystem &customMaterialSystem(*subsetRenderable.renderer->contextInterface()->customMaterialSystem().get());
        customMaterialSystem.rhiRenderRenderable(rhiCtx, subsetRenderable, needsSetViewport, cubeFace, state);
        break;
    }
    case QSSGRenderableObject::Type::Particles:
    {
        QSSGParticlesRenderable &renderable(static_cast<QSSGParticlesRenderable &>(object));
        QSSGParticleRenderer::rhiRenderRenderable(rhiCtx, renderable, needsSetViewport, cubeFace, state);
        break;
    }
    }
}
 
void RenderHelpers::rhiRenderShadowMap(QSSGRhiContext *rhiCtx,
                                       QSSGPassKey passKey,
                                       QSSGRhiGraphicsPipelineState &ps,
                                       QSSGRenderShadowMap &shadowMapManager,
                                       const QSSGRenderCamera &camera,
                                       const QSSGShaderLightList &globalLights,
                                       const QVector<QSSGRenderableObjectHandle> &sortedOpaqueObjects,
                                       QSSGRenderer &renderer,
                                       const QSSGBoxPoints &castingObjectsBox,
                                       const QSSGBoxPoints &receivingObjectsBox)
{
    const QSSGLayerGlobalRenderProperties &globalRenderProperties = renderer.getLayerGlobalRenderProperties();
    QSSG_ASSERT(globalRenderProperties.layer.renderData, return);
    const QSSGLayerRenderData &layerData = *globalRenderProperties.layer.renderData;
 
    static const auto rhiRenderOneShadowMap = [](QSSGRhiContext *rhiCtx,
                                                 QSSGRhiGraphicsPipelineState *ps,
                                                 const QVector<QSSGRenderableObjectHandle> &sortedOpaqueObjects,
                                                 int cubeFace) {
        QRhiCommandBuffer *cb = rhiCtx->commandBuffer();
        bool needsSetViewport = true;
 
        for (const auto &handle : sortedOpaqueObjects) {
            QSSGRenderableObject *theObject = handle.obj;
            QSSG_ASSERT(theObject->renderableFlags.castsShadows(), continue);
            if (theObject->type == QSSGRenderableObject::Type::DefaultMaterialMeshSubset || theObject->type == QSSGRenderableObject::Type::CustomMaterialMeshSubset) {
                QSSGSubsetRenderable *renderable(static_cast<QSSGSubsetRenderable *>(theObject));
 
                QRhiBuffer *vertexBuffer = renderable->subset.rhi.vertexBuffer->buffer();
                QRhiBuffer *indexBuffer = renderable->subset.rhi.indexBuffer
                        ? renderable->subset.rhi.indexBuffer->buffer()
                        : nullptr;
 
                     // Ideally we shouldn't need to deal with this, as only "valid" objects should be processed at this point.
                if (!renderable->rhiRenderData.shadowPass.pipeline)
                    continue;
 
                Q_QUICK3D_PROFILE_START(QQuick3DProfiler::Quick3DRenderCall);
 
                cb->setGraphicsPipeline(renderable->rhiRenderData.shadowPass.pipeline);
 
                QRhiShaderResourceBindings *srb = renderable->rhiRenderData.shadowPass.srb[cubeFace];
                cb->setShaderResources(srb);
 
                if (needsSetViewport) {
                    cb->setViewport(ps->viewport);
                    needsSetViewport = false;
                }
 
                QRhiCommandBuffer::VertexInput vertexBuffers[2];
                int vertexBufferCount = 1;
                vertexBuffers[0] = QRhiCommandBuffer::VertexInput(vertexBuffer, 0);
                quint32 instances = 1;
                if (renderable->modelContext.model.instancing()) {
                    instances = renderable->modelContext.model.instanceCount();
                    vertexBuffers[1] = QRhiCommandBuffer::VertexInput(renderable->instanceBuffer, 0);
                    vertexBufferCount = 2;
                }
                if (indexBuffer) {
                    cb->setVertexInput(0, vertexBufferCount, vertexBuffers, indexBuffer, 0, renderable->subset.rhi.indexBuffer->indexFormat());
                    cb->drawIndexed(renderable->subset.count, instances, renderable->subset.offset);
                    QSSGRHICTX_STAT(rhiCtx, drawIndexed(renderable->subset.count, instances));
                } else {
                    cb->setVertexInput(0, vertexBufferCount, vertexBuffers);
                    cb->draw(renderable->subset.count, instances, renderable->subset.offset);
                    QSSGRHICTX_STAT(rhiCtx, draw(renderable->subset.count, instances));
                }
                Q_QUICK3D_PROFILE_END_WITH_IDS(QQuick3DProfiler::Quick3DRenderCall, (renderable->subset.count | quint64(instances) << 32),
                                                 QVector<int>({renderable->modelContext.model.profilingId,
                                                  renderable->material.profilingId}));
            }
        }
    };
 
    static const auto rhiBlurShadowMap = [](QSSGRhiContext *rhiCtx,
                                            QSSGShadowMapEntry *pEntry,
                                            QSSGRenderer &renderer,
                                            float shadowFilter,
                                            float shadowMapFar,
                                            bool orthographic) {
        // may not be able to do the blur pass if the number of max color
        // attachments is the gl/vk spec mandated minimum of 4, and we need 6.
        // (applicable only to !orthographic, whereas orthographic always works)
        if (!pEntry->m_rhiBlurRenderTarget0 || !pEntry->m_rhiBlurRenderTarget1)
            return;
 
        QRhi *rhi = rhiCtx->rhi();
        QSSGRhiGraphicsPipelineState ps;
        QRhiTexture *map = orthographic ? pEntry->m_rhiDepthMap : pEntry->m_rhiDepthCube;
        QRhiTexture *workMap = orthographic ? pEntry->m_rhiDepthCopy : pEntry->m_rhiCubeCopy;
        const QSize size = map->pixelSize();
        ps.viewport = QRhiViewport(0, 0, float(size.width()), float(size.height()));
 
        const auto &blurXPipeline = orthographic ? renderer.getRhiOrthographicShadowBlurXShader()
                                                  : renderer.getRhiCubemapShadowBlurXShader();
        if (!blurXPipeline)
            return;
        ps.shaderPipeline = blurXPipeline.get();
 
        ps.colorAttachmentCount = orthographic ? 1 : 6;
 
        // construct a key that is unique for this frame (we use a dynamic buffer
        // so even if the same key gets used in the next frame, just updating the
        // contents on the same QRhiBuffer is ok due to QRhi's internal double buffering)
        QSSGRhiDrawCallData &dcd = rhiCtx->drawCallData({ map, nullptr, nullptr, 0, QSSGRhiDrawCallDataKey::ShadowBlur });
        if (!dcd.ubuf) {
            dcd.ubuf = rhi->newBuffer(QRhiBuffer::Dynamic, QRhiBuffer::UniformBuffer, 64 + 8);
            dcd.ubuf->create();
        }
 
        // the blur also needs Y reversed in order to get correct results (while
        // the second blur step would end up with the correct orientation without
        // this too, but we need to blur the correct fragments in the second step
        // hence the flip is important)
        QMatrix4x4 flipY;
        // correct for D3D and Metal but not for Vulkan because there the Y is down
        // in NDC so that kind of self-corrects...
        if (rhi->isYUpInFramebuffer() != rhi->isYUpInNDC())
            flipY.data()[5] = -1.0f;
        float cameraProperties[2] = { shadowFilter, shadowMapFar };
        char *ubufData = dcd.ubuf->beginFullDynamicBufferUpdateForCurrentFrame();
        memcpy(ubufData, flipY.constData(), 64);
        memcpy(ubufData + 64, cameraProperties, 8);
        dcd.ubuf->endFullDynamicBufferUpdateForCurrentFrame();
 
        QRhiSampler *sampler = rhiCtx->sampler({ QRhiSampler::Linear, QRhiSampler::Linear, QRhiSampler::None,
                                                 QRhiSampler::ClampToEdge, QRhiSampler::ClampToEdge, QRhiSampler::Repeat });
        Q_ASSERT(sampler);
 
        QSSGRhiShaderResourceBindingList bindings;
        bindings.addUniformBuffer(0, RENDERER_VISIBILITY_ALL, dcd.ubuf);
        bindings.addTexture(1, QRhiShaderResourceBinding::FragmentStage, map, sampler);
        QRhiShaderResourceBindings *srb = rhiCtx->srb(bindings);
 
        QSSGRhiQuadRenderer::Flags quadFlags;
        if (orthographic) // orthoshadowshadowblurx and y have attr_uv as well
            quadFlags |= QSSGRhiQuadRenderer::UvCoords;
        renderer.rhiQuadRenderer()->prepareQuad(rhiCtx, nullptr);
        renderer.rhiQuadRenderer()->recordRenderQuadPass(rhiCtx, &ps, srb, pEntry->m_rhiBlurRenderTarget0, quadFlags);
 
        // repeat for blur Y, now depthCopy -> depthMap or cubeCopy -> depthCube
 
        const auto &blurYPipeline = orthographic ? renderer.getRhiOrthographicShadowBlurYShader()
                                                 : renderer.getRhiCubemapShadowBlurYShader();
        if (!blurYPipeline)
            return;
        ps.shaderPipeline = blurYPipeline.get();
 
        bindings.clear();
        bindings.addUniformBuffer(0, RENDERER_VISIBILITY_ALL, dcd.ubuf);
        bindings.addTexture(1, QRhiShaderResourceBinding::FragmentStage, workMap, sampler);
        srb = rhiCtx->srb(bindings);
 
        renderer.rhiQuadRenderer()->prepareQuad(rhiCtx, nullptr);
        renderer.rhiQuadRenderer()->recordRenderQuadPass(rhiCtx, &ps, srb, pEntry->m_rhiBlurRenderTarget1, quadFlags);
    };
 
    QRhi *rhi = rhiCtx->rhi();
    QRhiCommandBuffer *cb = rhiCtx->commandBuffer();
 
    // We need to deal with a clip depth range of [0, 1] or
    // [-1, 1], depending on the graphics API underneath.
    QVector2D depthAdjust; // (d + depthAdjust[0]) * depthAdjust[1] = d mapped to [0, 1]
    if (rhi->isClipDepthZeroToOne()) {
        // d is [0, 1] so no need for any mapping
        depthAdjust[0] = 0.0f;
        depthAdjust[1] = 1.0f;
    } else {
        // d is [-1, 1]
        depthAdjust[0] = 1.0f;
        depthAdjust[1] = 0.5f;
    }
 
    // Create shadow map for each light in the scene
    for (int i = 0, ie = globalLights.size(); i != ie; ++i) {
        if (!globalLights[i].shadows || globalLights[i].light->m_fullyBaked)
            continue;
 
        QSSGShadowMapEntry *pEntry = shadowMapManager.shadowMapEntry(i);
        if (!pEntry)
            continue;
 
        Q_ASSERT(pEntry->m_rhiDepthStencil);
        const bool orthographic = pEntry->m_rhiDepthMap && pEntry->m_rhiDepthCopy;
        if (orthographic) {
            const QSize size = pEntry->m_rhiDepthMap->pixelSize();
            ps.viewport = QRhiViewport(0, 0, float(size.width()), float(size.height()));
 
            const auto &light = globalLights[i].light;
            const auto cameraType = (light->type == QSSGRenderLight::Type::DirectionalLight) ? QSSGRenderCamera::Type::OrthographicCamera : QSSGRenderCamera::Type::CustomCamera;
            QSSGRenderCamera theCamera(cameraType);
            setupCameraForShadowMap(camera, light, theCamera, castingObjectsBox, receivingObjectsBox);
            theCamera.calculateViewProjectionMatrix(pEntry->m_lightVP);
            pEntry->m_lightView = theCamera.globalTransform.inverted(); // pre-calculate this for the material
 
            rhiPrepareResourcesForShadowMap(rhiCtx, layerData, passKey, globalRenderProperties, pEntry, &ps, &depthAdjust,
                                            sortedOpaqueObjects, theCamera, true, 0);
 
            // Render into the 2D texture pEntry->m_rhiDepthMap, using
            // pEntry->m_rhiDepthStencil as the (throwaway) depth/stencil buffer.
            QRhiTextureRenderTarget *rt = pEntry->m_rhiRenderTargets[0];
            cb->beginPass(rt, Qt::white, { 1.0f, 0 }, nullptr, QSSGRhiContext::commonPassFlags());
            Q_QUICK3D_PROFILE_START(QQuick3DProfiler::Quick3DRenderPass);
            QSSGRHICTX_STAT(rhiCtx, beginRenderPass(rt));
            rhiRenderOneShadowMap(rhiCtx, &ps, sortedOpaqueObjects, 0);
            cb->endPass();
            QSSGRHICTX_STAT(rhiCtx, endRenderPass());
            Q_QUICK3D_PROFILE_END_WITH_STRING(QQuick3DProfiler::Quick3DRenderPass, 0, QByteArrayLiteral("shadow_map"));
 
            Q_QUICK3D_PROFILE_START(QQuick3DProfiler::Quick3DRenderPass);
            rhiBlurShadowMap(rhiCtx, pEntry, renderer, globalLights[i].light->m_shadowFilter, globalLights[i].light->m_shadowMapFar, true);
            Q_QUICK3D_PROFILE_END_WITH_STRING(QQuick3DProfiler::Quick3DRenderPass, 0, QByteArrayLiteral("shadow_map_blur"));
        } else {
            Q_ASSERT(pEntry->m_rhiDepthCube && pEntry->m_rhiCubeCopy);
            const QSize size = pEntry->m_rhiDepthCube->pixelSize();
            ps.viewport = QRhiViewport(0, 0, float(size.width()), float(size.height()));
 
            QSSGRenderCamera theCameras[6] { QSSGRenderCamera{QSSGRenderCamera::Type::PerspectiveCamera},
                                             QSSGRenderCamera{QSSGRenderCamera::Type::PerspectiveCamera},
                                             QSSGRenderCamera{QSSGRenderCamera::Type::PerspectiveCamera},
                                             QSSGRenderCamera{QSSGRenderCamera::Type::PerspectiveCamera},
                                             QSSGRenderCamera{QSSGRenderCamera::Type::PerspectiveCamera},
                                             QSSGRenderCamera{QSSGRenderCamera::Type::PerspectiveCamera} };
            setupCubeShadowCameras(globalLights[i].light, theCameras);
            pEntry->m_lightView = QMatrix4x4();
 
            const bool swapYFaces = !rhi->isYUpInFramebuffer();
            for (const auto face : QSSGRenderTextureCubeFaces) {
                theCameras[quint8(face)].calculateViewProjectionMatrix(pEntry->m_lightVP);
                pEntry->m_lightCubeView[quint8(face)] = theCameras[quint8(face)].globalTransform.inverted(); // pre-calculate this for the material
 
                rhiPrepareResourcesForShadowMap(rhiCtx, layerData, passKey, globalRenderProperties, pEntry, &ps, &depthAdjust,
                                                sortedOpaqueObjects, theCameras[quint8(face)], false, quint8(face));
            }
 
            for (const auto face : QSSGRenderTextureCubeFaces) {
                // Render into one face of the cubemap texture pEntry->m_rhiDephCube, using
                // pEntry->m_rhiDepthStencil as the (throwaway) depth/stencil buffer.
 
                QSSGRenderTextureCubeFace outFace = face;
                // FACE  S  T               GL
                // +x   -z, -y   right
                // -x   +z, -y   left
                // +y   +x, +z   top
                // -y   +x, -z   bottom
                // +z   +x, -y   front
                // -z   -x, -y   back
                // FACE  S  T               D3D
                // +x   -z, +y   right
                // -x   +z, +y   left
                // +y   +x, -z   bottom
                // -y   +x, +z   top
                // +z   +x, +y   front
                // -z   -x, +y   back
                if (swapYFaces) {
                    // +Y and -Y faces get swapped (D3D, Vulkan, Metal).
                    // See shadowMapping.glsllib. This is complemented there by reversing T as well.
                    if (outFace == QSSGRenderTextureCubeFace::PosY)
                        outFace = QSSGRenderTextureCubeFace::NegY;
                    else if (outFace == QSSGRenderTextureCubeFace::NegY)
                        outFace = QSSGRenderTextureCubeFace::PosY;
                }
                QRhiTextureRenderTarget *rt = pEntry->m_rhiRenderTargets[quint8(outFace)];
                cb->beginPass(rt, Qt::white, { 1.0f, 0 }, nullptr, QSSGRhiContext::commonPassFlags());
                QSSGRHICTX_STAT(rhiCtx, beginRenderPass(rt));
                Q_QUICK3D_PROFILE_START(QQuick3DProfiler::Quick3DRenderPass);
                rhiRenderOneShadowMap(rhiCtx, &ps, sortedOpaqueObjects, quint8(face));
                cb->endPass();
                QSSGRHICTX_STAT(rhiCtx, endRenderPass());
                Q_QUICK3D_PROFILE_END_WITH_STRING(QQuick3DProfiler::Quick3DRenderPass, 0, QSSG_RENDERPASS_NAME("shadow_cube", 0, outFace));
            }
 
            Q_QUICK3D_PROFILE_START(QQuick3DProfiler::Quick3DRenderPass);
            rhiBlurShadowMap(rhiCtx, pEntry, renderer, globalLights[i].light->m_shadowFilter, globalLights[i].light->m_shadowMapFar, false);
            Q_QUICK3D_PROFILE_END_WITH_STRING(QQuick3DProfiler::Quick3DRenderPass, 0, QByteArrayLiteral("shadow_cube_blur"));
        }
    }
}
 
void RenderHelpers::rhiRenderReflectionMap(QSSGRhiContext *rhiCtx,
                                           QSSGPassKey passKey,
                                           const QSSGLayerRenderData &inData,
                                           QSSGRhiGraphicsPipelineState *ps,
                                           QSSGRenderReflectionMap &reflectionMapManager,
                                           const QVector<QSSGRenderReflectionProbe *> &reflectionProbes,
                                           const QVector<QSSGRenderableObjectHandle> &reflectionPassObjects,
                                           QSSGRenderer &renderer)
{
    QRhi *rhi = rhiCtx->rhi();
    QRhiCommandBuffer *cb = rhiCtx->commandBuffer();
 
    const bool renderSkybox = (inData.layer.background == QSSGRenderLayer::Background::SkyBox ||
                               inData.layer.background == QSSGRenderLayer::Background::SkyBoxCubeMap)
            && rhiCtx->rhi()->isFeatureSupported(QRhi::TexelFetch);
 
    for (int i = 0, ie = reflectionProbes.size(); i != ie; ++i) {
        QSSGReflectionMapEntry *pEntry = reflectionMapManager.reflectionMapEntry(i);
        if (!pEntry)
            continue;
 
        if (!pEntry->m_needsRender)
            continue;
 
        if (reflectionProbes[i]->refreshMode == QSSGRenderReflectionProbe::ReflectionRefreshMode::FirstFrame && pEntry->m_rendered)
            continue;
 
        if (reflectionProbes[i]->texture)
            continue;
 
        Q_ASSERT(pEntry->m_rhiDepthStencil);
        Q_ASSERT(pEntry->m_rhiCube);
 
        const QSize size = pEntry->m_rhiCube->pixelSize();
        ps->viewport = QRhiViewport(0, 0, float(size.width()), float(size.height()));
 
        QSSGRenderCamera theCameras[6] { QSSGRenderCamera{QSSGRenderCamera::Type::PerspectiveCamera},
                                         QSSGRenderCamera{QSSGRenderCamera::Type::PerspectiveCamera},
                                         QSSGRenderCamera{QSSGRenderCamera::Type::PerspectiveCamera},
                                         QSSGRenderCamera{QSSGRenderCamera::Type::PerspectiveCamera},
                                         QSSGRenderCamera{QSSGRenderCamera::Type::PerspectiveCamera},
                                         QSSGRenderCamera{QSSGRenderCamera::Type::PerspectiveCamera} };
        setupCubeReflectionCameras(reflectionProbes[i], theCameras);
        const bool swapYFaces = !rhi->isYUpInFramebuffer();
        for (const auto face : QSSGRenderTextureCubeFaces) {
            theCameras[quint8(face)].calculateViewProjectionMatrix(pEntry->m_viewProjection);
 
            rhiPrepareResourcesForReflectionMap(rhiCtx, passKey, inData, pEntry, ps,
                                                reflectionPassObjects, theCameras[quint8(face)], renderer, quint8(face));
        }
        QRhiRenderPassDescriptor *renderPassDesc = nullptr;
        for (auto face : QSSGRenderTextureCubeFaces) {
            if (pEntry->m_timeSlicing == QSSGRenderReflectionProbe::ReflectionTimeSlicing::IndividualFaces)
                face = pEntry->m_timeSliceFace;
 
            QSSGRenderTextureCubeFace outFace = face;
            // Faces are swapped similarly to shadow maps due to differences in backends
            // Prefilter step handles correcting orientation differences in the final render
            if (swapYFaces) {
                if (outFace == QSSGRenderTextureCubeFace::PosY)
                    outFace = QSSGRenderTextureCubeFace::NegY;
                else if (outFace == QSSGRenderTextureCubeFace::NegY)
                    outFace = QSSGRenderTextureCubeFace::PosY;
            }
            QRhiTextureRenderTarget *rt = pEntry->m_rhiRenderTargets[quint8(outFace)];
            cb->beginPass(rt, reflectionProbes[i]->clearColor, { 1.0f, 0 }, nullptr, QSSGRhiContext::commonPassFlags());
            QSSGRHICTX_STAT(rhiCtx, beginRenderPass(rt));
            Q_QUICK3D_PROFILE_START(QQuick3DProfiler::Quick3DRenderPass);
 
            if (renderSkybox && pEntry->m_skyBoxSrbs[quint8(face)]) {
                const bool isSkyBox = inData.layer.background == QSSGRenderLayer::Background::SkyBox;
                const auto &shaderPipeline = isSkyBox ? renderer.getRhiSkyBoxShader(QSSGRenderLayer::TonemapMode::None, inData.layer.skyBoxIsRgbe8)
                                                      : renderer.getRhiSkyBoxCubeShader();
                Q_ASSERT(shaderPipeline);
                ps->shaderPipeline = shaderPipeline.get();
                QRhiShaderResourceBindings *srb = pEntry->m_skyBoxSrbs[quint8(face)];
                if (!renderPassDesc)
                    renderPassDesc = rt->newCompatibleRenderPassDescriptor();
                rt->setRenderPassDescriptor(renderPassDesc);
                isSkyBox ? renderer.rhiQuadRenderer()->recordRenderQuad(rhiCtx, ps, srb, renderPassDesc, {})
                         : renderer.rhiCubeRenderer()->recordRenderCube(rhiCtx, ps, srb, renderPassDesc, {});
            }
 
            bool needsSetViewport = true;
            for (const auto &handle : reflectionPassObjects)
                rhiRenderRenderable(rhiCtx, *ps, *handle.obj, &needsSetViewport, quint8(face));
 
            cb->endPass();
            QSSGRHICTX_STAT(rhiCtx, endRenderPass());
            Q_QUICK3D_PROFILE_END_WITH_STRING(QQuick3DProfiler::Quick3DRenderPass, 0, QSSG_RENDERPASS_NAME("reflection_cube", 0, outFace));
 
            if (pEntry->m_timeSlicing == QSSGRenderReflectionProbe::ReflectionTimeSlicing::IndividualFaces)
                break;
        }
        if (renderPassDesc)
            renderPassDesc->deleteLater();
 
        pEntry->renderMips(rhiCtx);
 
        if (pEntry->m_timeSlicing == QSSGRenderReflectionProbe::ReflectionTimeSlicing::IndividualFaces)
            pEntry->m_timeSliceFace = QSSGBaseTypeHelpers::next(pEntry->m_timeSliceFace); // Wraps
 
        if (reflectionProbes[i]->refreshMode == QSSGRenderReflectionProbe::ReflectionRefreshMode::FirstFrame)
            pEntry->m_rendered = true;
 
        reflectionProbes[i]->hasScheduledUpdate = false;
        pEntry->m_needsRender = false;
    }
}
 
bool RenderHelpers::rhiPrepareAoTexture(QSSGRhiContext *rhiCtx, const QSize &size, QSSGRhiRenderableTexture *renderableTex)
{
    QRhi *rhi = rhiCtx->rhi();
    bool needsBuild = false;
 
    if (!renderableTex->texture) {
        // the ambient occlusion texture is always non-msaa, even if multisampling is used in the main pass
        renderableTex->texture = rhiCtx->rhi()->newTexture(QRhiTexture::RGBA8, size, 1, QRhiTexture::RenderTarget);
        needsBuild = true;
    } else if (renderableTex->texture->pixelSize() != size) {
        renderableTex->texture->setPixelSize(size);
        needsBuild = true;
    }
 
    if (needsBuild) {
        if (!renderableTex->texture->create()) {
            qWarning("Failed to build ambient occlusion texture (size %dx%d)", size.width(), size.height());
            renderableTex->reset();
            return false;
        }
        renderableTex->resetRenderTarget();
        renderableTex->rt = rhi->newTextureRenderTarget({ renderableTex->texture });
        renderableTex->rt->setName(QByteArrayLiteral("Ambient occlusion"));
        renderableTex->rpDesc = renderableTex->rt->newCompatibleRenderPassDescriptor();
        renderableTex->rt->setRenderPassDescriptor(renderableTex->rpDesc);
        if (!renderableTex->rt->create()) {
            qWarning("Failed to build render target for ambient occlusion texture");
            renderableTex->reset();
            return false;
        }
    }
 
    return true;
}
 
void RenderHelpers::rhiRenderAoTexture(QSSGRhiContext *rhiCtx,
                                       QSSGPassKey passKey,
                                       QSSGRenderer &renderer,
                                       QSSGRhiShaderPipeline &shaderPipeline,
                                       QSSGRhiGraphicsPipelineState &ps,
                                       const SSAOMapPass::AmbientOcclusion &ao,
                                       const QSSGRhiRenderableTexture &rhiAoTexture,
                                       const QSSGRhiRenderableTexture &rhiDepthTexture,
                                       const QSSGRenderCamera &camera)
{
    // no texelFetch in GLSL <= 120 and GLSL ES 100
    if (!rhiCtx->rhi()->isFeatureSupported(QRhi::TexelFetch)) {
        QRhiCommandBuffer *cb = rhiCtx->commandBuffer();
        // just clear and stop there
        cb->beginPass(rhiAoTexture.rt, Qt::white, { 1.0f, 0 });
        QSSGRHICTX_STAT(rhiCtx, beginRenderPass(rhiAoTexture.rt));
        cb->endPass();
        QSSGRHICTX_STAT(rhiCtx, endRenderPass());
        return;
    }
 
    ps.shaderPipeline = &shaderPipeline;
 
    const float R2 = ao.aoDistance * ao.aoDistance * 0.16f;
    const QSize textureSize = rhiAoTexture.texture->pixelSize();
    const float rw = float(textureSize.width());
    const float rh = float(textureSize.height());
    const float fov = camera.verticalFov(rw / rh);
    const float tanHalfFovY = tanf(0.5f * fov * (rh / rw));
    const float invFocalLenX = tanHalfFovY * (rw / rh);
 
    const QVector4D aoProps(ao.aoStrength * 0.01f, ao.aoDistance * 0.4f, ao.aoSoftness * 0.02f, ao.aoBias);
    const QVector4D aoProps2(float(ao.aoSamplerate), (ao.aoDither) ? 1.0f : 0.0f, 0.0f, 0.0f);
    const QVector4D aoScreenConst(1.0f / R2, rh / (2.0f * tanHalfFovY), 1.0f / rw, 1.0f / rh);
    const QVector4D uvToEyeConst(2.0f * invFocalLenX, -2.0f * tanHalfFovY, -invFocalLenX, tanHalfFovY);
    const QVector2D cameraProps(camera.clipNear, camera.clipFar);
 
    //    layout(std140, binding = 0) uniform buf {
    //        vec4 aoProperties;
    //        vec4 aoProperties2;
    //        vec4 aoScreenConst;
    //        vec4 uvToEyeConst;
    //        vec2 cameraProperties;
 
    const int UBUF_SIZE = 72;
    QSSGRhiDrawCallData &dcd(rhiCtx->drawCallData({ passKey, nullptr, nullptr, 0, QSSGRhiDrawCallDataKey::AoTexture }));
    if (!dcd.ubuf) {
        dcd.ubuf = rhiCtx->rhi()->newBuffer(QRhiBuffer::Dynamic, QRhiBuffer::UniformBuffer, UBUF_SIZE);
        dcd.ubuf->create();
    }
 
    char *ubufData = dcd.ubuf->beginFullDynamicBufferUpdateForCurrentFrame();
    memcpy(ubufData, &aoProps, 16);
    memcpy(ubufData + 16, &aoProps2, 16);
    memcpy(ubufData + 32, &aoScreenConst, 16);
    memcpy(ubufData + 48, &uvToEyeConst, 16);
    memcpy(ubufData + 64, &cameraProps, 8);
    dcd.ubuf->endFullDynamicBufferUpdateForCurrentFrame();
 
    QRhiSampler *sampler = rhiCtx->sampler({ QRhiSampler::Nearest, QRhiSampler::Nearest, QRhiSampler::None,
                                             QRhiSampler::ClampToEdge, QRhiSampler::ClampToEdge, QRhiSampler::Repeat });
    QSSGRhiShaderResourceBindingList bindings;
    bindings.addUniformBuffer(0, RENDERER_VISIBILITY_ALL, dcd.ubuf);
    bindings.addTexture(1, QRhiShaderResourceBinding::FragmentStage, rhiDepthTexture.texture, sampler);
    QRhiShaderResourceBindings *srb = rhiCtx->srb(bindings);
 
    renderer.rhiQuadRenderer()->prepareQuad(rhiCtx, nullptr);
    renderer.rhiQuadRenderer()->recordRenderQuadPass(rhiCtx, &ps, srb, rhiAoTexture.rt, {});
}
 
bool RenderHelpers::rhiPrepareScreenTexture(QSSGRhiContext *rhiCtx, const QSize &size, bool wantsMips, QSSGRhiRenderableTexture *renderableTex)
{
    QRhi *rhi = rhiCtx->rhi();
    bool needsBuild = false;
    QRhiTexture::Flags flags = QRhiTexture::RenderTarget;
    if (wantsMips)
        flags |= QRhiTexture::MipMapped | QRhiTexture::UsedWithGenerateMips;
 
    if (!renderableTex->texture) {
        // always non-msaa, even if multisampling is used in the main pass
        renderableTex->texture = rhi->newTexture(QRhiTexture::RGBA8, size, 1, flags);
        needsBuild = true;
    } else if (renderableTex->texture->pixelSize() != size) {
        renderableTex->texture->setPixelSize(size);
        needsBuild = true;
    }
 
    if (!renderableTex->depthStencil) {
        renderableTex->depthStencil = rhi->newRenderBuffer(QRhiRenderBuffer::DepthStencil, size);
        needsBuild = true;
    } else if (renderableTex->depthStencil->pixelSize() != size) {
        renderableTex->depthStencil->setPixelSize(size);
        needsBuild = true;
    }
 
    if (needsBuild) {
        if (!renderableTex->texture->create()) {
            qWarning("Failed to build screen texture (size %dx%d)", size.width(), size.height());
            renderableTex->reset();
            return false;
        }
        if (!renderableTex->depthStencil->create()) {
            qWarning("Failed to build depth-stencil buffer for screen texture (size %dx%d)",
                     size.width(), size.height());
            renderableTex->reset();
            return false;
        }
        renderableTex->resetRenderTarget();
        QRhiTextureRenderTargetDescription desc;
        desc.setColorAttachments({ QRhiColorAttachment(renderableTex->texture) });
        desc.setDepthStencilBuffer(renderableTex->depthStencil);
        renderableTex->rt = rhi->newTextureRenderTarget(desc);
        renderableTex->rt->setName(QByteArrayLiteral("Screen texture"));
        renderableTex->rpDesc = renderableTex->rt->newCompatibleRenderPassDescriptor();
        renderableTex->rt->setRenderPassDescriptor(renderableTex->rpDesc);
        if (!renderableTex->rt->create()) {
            qWarning("Failed to build render target for screen texture");
            renderableTex->reset();
            return false;
        }
    }
 
    return true;
}
 
void RenderHelpers::rhiPrepareGrid(QSSGRhiContext *rhiCtx, QSSGRenderLayer &layer, QSSGRenderCamera &inCamera, QSSGRenderer &renderer)
{
    QRhiCommandBuffer *cb = rhiCtx->commandBuffer();
    cb->debugMarkBegin(QByteArrayLiteral("Quick3D prepare grid"));
 
    QSSGRhiShaderResourceBindingList bindings;
 
    int uniformBinding = 0;
    const int ubufSize = 64 * 2 * sizeof(float) + 4 * sizeof(float) + 4 * sizeof(quint32); // 2x mat4 + 4x float + 1x bool
 
    QSSGRhiDrawCallData &dcd(rhiCtx->drawCallData({ &layer, nullptr, nullptr, 0, QSSGRhiDrawCallDataKey::Main })); // Change to Grid?
 
    QRhi *rhi = rhiCtx->rhi();
    if (!dcd.ubuf) {
        dcd.ubuf = rhi->newBuffer(QRhiBuffer::Dynamic, QRhiBuffer::UniformBuffer, ubufSize);
        dcd.ubuf->create();
    }
 
    // Param
    const float nearF = inCamera.clipNear;
    const float farF = inCamera.clipFar;
    const float scale = layer.gridScale;
    const quint32 gridFlags = layer.gridFlags;
 
    const float yFactor = rhi->isYUpInNDC() ? 1.0f : -1.0f;
 
    QMatrix4x4 viewProj(Qt::Uninitialized);
    inCamera.calculateViewProjectionMatrix(viewProj);
    QMatrix4x4 invViewProj = viewProj.inverted();
 
    char *ubufData = dcd.ubuf->beginFullDynamicBufferUpdateForCurrentFrame();
    memcpy(ubufData + 64 * 0, viewProj.constData(), 64);
    memcpy(ubufData + 64 * 1, invViewProj.constData(), 64);
    memcpy(ubufData + 64 * 2 + 0, &nearF, 4);
    memcpy(ubufData + 64 * 2 + 4 * 1, &farF, 4);
    memcpy(ubufData + 64 * 2 + 4 * 2, &scale, 4);
    memcpy(ubufData + 64 * 2 + 4 * 3, &yFactor, 4);
    memcpy(ubufData + 64 * 2 + 4 * 4, &gridFlags, 4);
    dcd.ubuf->endFullDynamicBufferUpdateForCurrentFrame();
 
    bindings.addUniformBuffer(uniformBinding, RENDERER_VISIBILITY_ALL, dcd.ubuf);
 
    layer.gridSrb = rhiCtx->srb(bindings);
    renderer.rhiQuadRenderer()->prepareQuad(rhiCtx, nullptr);
 
    cb->debugMarkEnd();
}
 
namespace {
void rhiPrepareSkyBox_helper(QSSGRhiContext *rhiCtx,
                             QSSGPassKey passKey,
                             QSSGRenderLayer &layer,
                             QSSGRenderCamera &inCamera,
                             QSSGRenderer &renderer,
                             QSSGReflectionMapEntry *entry = nullptr,
                             int cubeFace = -1)
{
    const bool cubeMapMode = layer.background == QSSGRenderLayer::Background::SkyBoxCubeMap;
    const QSSGRenderImageTexture lightProbeTexture =
            cubeMapMode ? renderer.contextInterface()->bufferManager()->loadRenderImage(layer.skyBoxCubeMap, QSSGBufferManager::MipModeDisable)
                        : renderer.contextInterface()->bufferManager()->loadRenderImage(layer.lightProbe, QSSGBufferManager::MipModeBsdf);
    const bool hasValidTexture = lightProbeTexture.m_texture != nullptr;
    if (hasValidTexture) {
        if (cubeFace < 0)
            layer.skyBoxIsRgbe8 = lightProbeTexture.m_flags.isRgbe8();
 
        QSSGRhiShaderResourceBindingList bindings;
 
        QRhiSampler *sampler = rhiCtx->sampler({ QRhiSampler::Linear,
                                                 QRhiSampler::Linear,
                                                 cubeMapMode ? QRhiSampler::None : QRhiSampler::Linear, // cube map doesn't have mipmaps
                                                 QRhiSampler::Repeat,
                                                 QRhiSampler::ClampToEdge,
                                                 QRhiSampler::Repeat });
        int samplerBinding = 1; //the shader code is hand-written, so we don't need to look that up
        const int ubufSize = 2 * 4 * 3 * sizeof(float) + 2 * 4 * 4 * sizeof(float) + 2 * sizeof(float); // 2x mat3 + 2x mat4 + 2 floats
        bindings.addTexture(samplerBinding,
                            QRhiShaderResourceBinding::FragmentStage,
                            lightProbeTexture.m_texture, sampler);
 
        QSSGRhiDrawCallData &dcd(cubeFace >= 0 ? rhiCtx->drawCallData({ passKey, nullptr, entry, cubeFace, QSSGRhiDrawCallDataKey::Reflection })
                                               : rhiCtx->drawCallData({ passKey, nullptr, nullptr, 0, QSSGRhiDrawCallDataKey::SkyBox }));
 
        QRhi *rhi = rhiCtx->rhi();
        if (!dcd.ubuf) {
            dcd.ubuf = rhi->newBuffer(QRhiBuffer::Dynamic, QRhiBuffer::UniformBuffer, ubufSize);
            dcd.ubuf->create();
        }
 
        const QMatrix4x4 &inverseProjection = inCamera.projection.inverted();
        const QMatrix4x4 &viewMatrix = inCamera.globalTransform;
        QMatrix4x4 viewProjection(Qt::Uninitialized); // For cube mode
        inCamera.calculateViewProjectionWithoutTranslation(0.1f, 5.0f, viewProjection);
 
        float adjustY = rhi->isYUpInNDC() ? 1.0f : -1.0f;
        const float exposure = layer.probeExposure;
        // orientation
        const QMatrix3x3 &rotationMatrix(layer.probeOrientation);
        const float blurAmount = layer.skyboxBlurAmount;
        const float maxMipLevel = float(lightProbeTexture.m_mipmapCount - 2);
 
        const QVector4D skyboxProperties = {
            adjustY,
            exposure,
            blurAmount,
            maxMipLevel
        };
 
        char *ubufData = dcd.ubuf->beginFullDynamicBufferUpdateForCurrentFrame();
        memcpy(ubufData, viewMatrix.constData(), 44);
        memcpy(ubufData + 48, inverseProjection.constData(), 64);
        memcpy(ubufData + 112, rotationMatrix.constData(), 12);
        memcpy(ubufData + 128, (char *)rotationMatrix.constData() + 12, 12);
        memcpy(ubufData + 144, (char *)rotationMatrix.constData() + 24, 12);
        memcpy(ubufData + 160, &skyboxProperties, 16);
        memcpy(ubufData + 176, viewProjection.constData(), 64); //###
        dcd.ubuf->endFullDynamicBufferUpdateForCurrentFrame();
 
        bindings.addUniformBuffer(0, RENDERER_VISIBILITY_ALL, dcd.ubuf);
 
        if (cubeFace >= 0)
            entry->m_skyBoxSrbs[cubeFace] = rhiCtx->srb(bindings);
        else
            layer.skyBoxSrb = rhiCtx->srb(bindings);
 
        if (cubeMapMode)
            renderer.rhiCubeRenderer()->prepareCube(rhiCtx, nullptr);
        else
            renderer.rhiQuadRenderer()->prepareQuad(rhiCtx, nullptr);
    }
}
} // namespace
 
void RenderHelpers::rhiPrepareSkyBox(QSSGRhiContext *rhiCtx,
                                     QSSGPassKey passKey,
                                     QSSGRenderLayer &layer,
                                     QSSGRenderCamera &inCamera,
                                     QSSGRenderer &renderer)
{
    QRhiCommandBuffer *cb = rhiCtx->commandBuffer();
    cb->debugMarkBegin(QByteArrayLiteral("Quick3D prepare skybox"));
 
    rhiPrepareSkyBox_helper(rhiCtx, passKey, layer, inCamera, renderer);
 
    cb->debugMarkEnd();
}
 
void RenderHelpers::rhiPrepareSkyBoxForReflectionMap(QSSGRhiContext *rhiCtx,
                                                     QSSGPassKey passKey,
                                                     QSSGRenderLayer &layer,
                                                     QSSGRenderCamera &inCamera,
                                                     QSSGRenderer &renderer,
                                                     QSSGReflectionMapEntry *entry,
                                                     int cubeFace)
{
    QRhiCommandBuffer *cb = rhiCtx->commandBuffer();
    cb->debugMarkBegin(QByteArrayLiteral("Quick3D prepare skybox for reflection cube map"));
 
    rhiPrepareSkyBox_helper(rhiCtx, passKey, layer, inCamera, renderer, entry, cubeFace);
 
    cb->debugMarkEnd();
}
 
bool RenderHelpers::rhiPrepareDepthPass(QSSGRhiContext *rhiCtx,
                                        QSSGPassKey passKey,
                                        const QSSGRhiGraphicsPipelineState &basePipelineState,
                                        QRhiRenderPassDescriptor *rpDesc,
                                        QSSGLayerRenderData &inData,
                                        const QVector<QSSGRenderableObjectHandle> &sortedOpaqueObjects,
                                        const QVector<QSSGRenderableObjectHandle> &sortedTransparentObjects,
                                        QSSGRhiDrawCallDataKey::Selector ubufSel,
                                        int samples)
{
    static const auto rhiPrepareDepthPassForObject = [](QSSGRhiContext *rhiCtx,
                                                        QSSGPassKey passKey,
                                                        QSSGLayerRenderData &inData,
                                                        QSSGRenderableObject *obj,
                                                        QRhiRenderPassDescriptor *rpDesc,
                                                        QSSGRhiGraphicsPipelineState *ps,
                                                        QSSGRhiDrawCallDataKey::Selector ubufSel) {
        QSSGRhiShaderPipelinePtr shaderPipeline;
 
        const bool isOpaqueDepthPrePass = obj->depthWriteMode == QSSGDepthDrawMode::OpaquePrePass;
        QSSGShaderFeatures featureSet;
        featureSet.set(QSSGShaderFeatures::Feature::DepthPass, true);
        if (isOpaqueDepthPrePass)
            featureSet.set(QSSGShaderFeatures::Feature::OpaqueDepthPrePass, true);
 
        QSSGRhiDrawCallData *dcd = nullptr;
        if (obj->type == QSSGRenderableObject::Type::DefaultMaterialMeshSubset || obj->type == QSSGRenderableObject::Type::CustomMaterialMeshSubset) {
            QSSGSubsetRenderable &subsetRenderable(static_cast<QSSGSubsetRenderable &>(*obj));
            const void *modelNode = &subsetRenderable.modelContext.model;
            dcd = &rhiCtx->drawCallData({ passKey, modelNode, &subsetRenderable.material, 0, ubufSel });
        }
 
        if (obj->type == QSSGRenderableObject::Type::DefaultMaterialMeshSubset) {
            QSSGSubsetRenderable &subsetRenderable(static_cast<QSSGSubsetRenderable &>(*obj));
            ps->cullMode = QSSGRhiGraphicsPipelineState::toCullMode(subsetRenderable.defaultMaterial().cullMode);
 
            shaderPipeline = shadersForDefaultMaterial(ps, subsetRenderable, featureSet);
            if (shaderPipeline) {
                shaderPipeline->ensureCombinedMainLightsUniformBuffer(&dcd->ubuf);
                char *ubufData = dcd->ubuf->beginFullDynamicBufferUpdateForCurrentFrame();
                updateUniformsForDefaultMaterial(*shaderPipeline, rhiCtx, inData, ubufData, ps, subsetRenderable, *inData.camera, nullptr, nullptr);
                dcd->ubuf->endFullDynamicBufferUpdateForCurrentFrame();
            } else {
                return false;
            }
        } else if (obj->type == QSSGRenderableObject::Type::CustomMaterialMeshSubset) {
            QSSGSubsetRenderable &subsetRenderable(static_cast<QSSGSubsetRenderable &>(*obj));
            ps->cullMode = QSSGRhiGraphicsPipelineState::toCullMode(subsetRenderable.customMaterial().m_cullMode);
 
            QSSGCustomMaterialSystem &customMaterialSystem(*subsetRenderable.renderer->contextInterface()->customMaterialSystem().get());
            shaderPipeline = customMaterialSystem.shadersForCustomMaterial(ps, subsetRenderable.customMaterial(), subsetRenderable, featureSet);
 
            if (shaderPipeline) {
                shaderPipeline->ensureCombinedMainLightsUniformBuffer(&dcd->ubuf);
                char *ubufData = dcd->ubuf->beginFullDynamicBufferUpdateForCurrentFrame();
                customMaterialSystem.updateUniformsForCustomMaterial(*shaderPipeline, rhiCtx, inData, ubufData, ps, subsetRenderable.customMaterial(), subsetRenderable,
                                                                     *inData.camera, nullptr, nullptr);
                dcd->ubuf->endFullDynamicBufferUpdateForCurrentFrame();
            } else {
                return false;
            }
        }
 
        // the rest is common, only relying on QSSGSubsetRenderableBase, not the subclasses
        if (obj->type == QSSGRenderableObject::Type::DefaultMaterialMeshSubset || obj->type == QSSGRenderableObject::Type::CustomMaterialMeshSubset) {
            QSSGSubsetRenderable &subsetRenderable(static_cast<QSSGSubsetRenderable &>(*obj));
            ps->ia = subsetRenderable.subset.rhi.ia;
 
            int instanceBufferBinding = setupInstancing(&subsetRenderable, ps, rhiCtx, inData.cameraData->direction, inData.cameraData->position);
            ps->ia.bakeVertexInputLocations(*shaderPipeline, instanceBufferBinding);
 
            QSSGRhiShaderResourceBindingList bindings;
            bindings.addUniformBuffer(0, RENDERER_VISIBILITY_ALL, dcd->ubuf);
 
            // Depth and SSAO textures, in case a custom material's shader code does something with them.
            addDepthTextureBindings(rhiCtx, shaderPipeline.get(), bindings);
 
            if (isOpaqueDepthPrePass) {
                addOpaqueDepthPrePassBindings(rhiCtx,
                                              shaderPipeline.get(),
                                              subsetRenderable.firstImage,
                                              bindings,
                                              (obj->type == QSSGRenderableObject::Type::CustomMaterialMeshSubset));
            }
 
            QRhiShaderResourceBindings *srb = rhiCtx->srb(bindings);
 
            subsetRenderable.rhiRenderData.depthPrePass.pipeline = rhiCtx->pipeline(QSSGGraphicsPipelineStateKey::create(*ps, rpDesc, srb),
                                                                                    rpDesc,
                                                                                    srb);
            subsetRenderable.rhiRenderData.depthPrePass.srb = srb;
        }
 
        return true;
    };
 
    // Phase 1 (prepare) for the Z prepass or the depth texture generation.
    // These renders opaque (Z prepass), or opaque and transparent (depth
    // texture), objects with depth test/write enabled, and color write
    // disabled, using a very simple set of shaders.
 
    QSSGRhiGraphicsPipelineState ps = basePipelineState; // viewport and others are filled out already
    // We took a copy of the pipeline state since we do not want to conflict
    // with what rhiPrepare() collects for its own use. So here just change
    // whatever we need.
 
    ps.samples = samples;
    ps.depthTestEnable = true;
    ps.depthWriteEnable = true;
    ps.targetBlend.colorWrite = {};
 
    for (const QSSGRenderableObjectHandle &handle : sortedOpaqueObjects) {
        if (!rhiPrepareDepthPassForObject(rhiCtx, passKey, inData, handle.obj, rpDesc, &ps, ubufSel))
            return false;
    }
 
    for (const QSSGRenderableObjectHandle &handle : sortedTransparentObjects) {
        if (!rhiPrepareDepthPassForObject(rhiCtx, passKey, inData, handle.obj, rpDesc, &ps, ubufSel))
            return false;
    }
 
    return true;
}
 
void RenderHelpers::rhiRenderDepthPass(QSSGRhiContext *rhiCtx,
                                       const QSSGRhiGraphicsPipelineState &pipelineState,
                                       const QVector<QSSGRenderableObjectHandle> &sortedOpaqueObjects,
                                       const QVector<QSSGRenderableObjectHandle> &sortedTransparentObjects,
                                       bool *needsSetViewport)
{
    static const auto rhiRenderDepthPassForImp = [](QSSGRhiContext *rhiCtx,
                                                    const QSSGRhiGraphicsPipelineState &pipelineState,
                                                    const QVector<QSSGRenderableObjectHandle> &objects,
                                                    bool *needsSetViewport) {
        for (const auto &oh : objects) {
            QSSGRenderableObject *obj = oh.obj;
 
                 // casts to SubsetRenderableBase so it works for both default and custom materials
            if (obj->type == QSSGRenderableObject::Type::DefaultMaterialMeshSubset || obj->type == QSSGRenderableObject::Type::CustomMaterialMeshSubset) {
                QRhiCommandBuffer *cb = rhiCtx->commandBuffer();
                QSSGSubsetRenderable *subsetRenderable(static_cast<QSSGSubsetRenderable *>(obj));
 
                QRhiBuffer *vertexBuffer = subsetRenderable->subset.rhi.vertexBuffer->buffer();
                QRhiBuffer *indexBuffer = subsetRenderable->subset.rhi.indexBuffer
                        ? subsetRenderable->subset.rhi.indexBuffer->buffer()
                        : nullptr;
 
                QRhiGraphicsPipeline *ps = subsetRenderable->rhiRenderData.depthPrePass.pipeline;
                if (!ps)
                    return;
 
                QRhiShaderResourceBindings *srb = subsetRenderable->rhiRenderData.depthPrePass.srb;
                if (!srb)
                    return;
 
                Q_QUICK3D_PROFILE_START(QQuick3DProfiler::Quick3DRenderCall);
                cb->setGraphicsPipeline(ps);
                cb->setShaderResources(srb);
 
                if (*needsSetViewport) {
                    cb->setViewport(pipelineState.viewport);
                    *needsSetViewport = false;
                }
 
                QRhiCommandBuffer::VertexInput vertexBuffers[2];
                int vertexBufferCount = 1;
                vertexBuffers[0] = QRhiCommandBuffer::VertexInput(vertexBuffer, 0);
                quint32 instances = 1;
                if (subsetRenderable->modelContext.model.instancing()) {
                    instances = subsetRenderable->modelContext.model.instanceCount();
                    vertexBuffers[1] = QRhiCommandBuffer::VertexInput(subsetRenderable->instanceBuffer, 0);
                    vertexBufferCount = 2;
                }
 
                if (indexBuffer) {
                    cb->setVertexInput(0, vertexBufferCount, vertexBuffers, indexBuffer, 0, subsetRenderable->subset.rhi.indexBuffer->indexFormat());
                    cb->drawIndexed(subsetRenderable->subset.count, instances, subsetRenderable->subset.offset);
                    QSSGRHICTX_STAT(rhiCtx, drawIndexed(subsetRenderable->subset.count, instances));
                } else {
                    cb->setVertexInput(0, vertexBufferCount, vertexBuffers);
                    cb->draw(subsetRenderable->subset.count, instances, subsetRenderable->subset.offset);
                    QSSGRHICTX_STAT(rhiCtx, draw(subsetRenderable->subset.count, instances));
                }
                Q_QUICK3D_PROFILE_END_WITH_IDS(QQuick3DProfiler::Quick3DRenderCall, (subsetRenderable->subset.count | quint64(instances) << 32),
                                                 QVector<int>({subsetRenderable->modelContext.model.profilingId,
                                                  subsetRenderable->material.profilingId}));
            }
        }
    };
 
    rhiRenderDepthPassForImp(rhiCtx, pipelineState, sortedOpaqueObjects, needsSetViewport);
    rhiRenderDepthPassForImp(rhiCtx, pipelineState, sortedTransparentObjects, needsSetViewport);
}
 
bool RenderHelpers::rhiPrepareDepthTexture(QSSGRhiContext *rhiCtx, const QSize &size, QSSGRhiRenderableTexture *renderableTex)
{
    QRhi *rhi = rhiCtx->rhi();
    bool needsBuild = false;
 
    if (!renderableTex->texture) {
        QRhiTexture::Format format = QRhiTexture::D32F;
        if (!rhi->isTextureFormatSupported(format))
            format = QRhiTexture::D16;
        if (!rhi->isTextureFormatSupported(format))
            qWarning("Depth texture not supported");
        // the depth texture is always non-msaa, even if multisampling is used in the main pass
        renderableTex->texture = rhiCtx->rhi()->newTexture(format, size, 1, QRhiTexture::RenderTarget);
        needsBuild = true;
    } else if (renderableTex->texture->pixelSize() != size) {
        renderableTex->texture->setPixelSize(size);
        needsBuild = true;
    }
 
    if (needsBuild) {
        if (!renderableTex->texture->create()) {
            qWarning("Failed to build depth texture (size %dx%d, format %d)",
                     size.width(), size.height(), int(renderableTex->texture->format()));
            renderableTex->reset();
            return false;
        }
        renderableTex->resetRenderTarget();
        QRhiTextureRenderTargetDescription rtDesc;
        rtDesc.setDepthTexture(renderableTex->texture);
        renderableTex->rt = rhi->newTextureRenderTarget(rtDesc);
        renderableTex->rt->setName(QByteArrayLiteral("Depth texture"));
        renderableTex->rpDesc = renderableTex->rt->newCompatibleRenderPassDescriptor();
        renderableTex->rt->setRenderPassDescriptor(renderableTex->rpDesc);
        if (!renderableTex->rt->create()) {
            qWarning("Failed to build render target for depth texture");
            renderableTex->reset();
            return false;
        }
    }
 
    return true;
}
 
QT_END_NAMESPACE