qsgmaterialshader.cpp

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// Copyright (C) 2019 The Qt Company Ltd.
// SPDX-License-Identifier: LicenseRef-Qt-Commercial OR LGPL-3.0-only OR GPL-2.0-only OR GPL-3.0-only
 
#include "qsgmaterial.h"
#include "qsgrenderer_p.h"
#include "qsgmaterialshader_p.h"
#include <QtCore/QFile>
 
QT_BEGIN_NAMESPACE
 
QShader QSGMaterialShaderPrivate::loadShader(const QString &filename)
{
    QFile f(filename);
    if (!f.open(QIODevice::ReadOnly)) {
        qWarning() << "Failed to find shader" << filename;
        return QShader();
    }
    return QShader::fromSerialized(f.readAll());
}
 
void QSGMaterialShaderPrivate::clearCachedRendererData()
{
    for (int i = 0; i < MAX_SHADER_RESOURCE_BINDINGS; ++i)
        textureBindingTable[i].clear();
    for (int i = 0; i < MAX_SHADER_RESOURCE_BINDINGS; ++i)
        samplerBindingTable[i].clear();
}
 
static inline QRhiShaderResourceBinding::StageFlags toSrbStage(QShader::Stage stage)
{
    switch (stage) {
    case QShader::VertexStage:
        return QRhiShaderResourceBinding::VertexStage;
    case QShader::FragmentStage:
        return QRhiShaderResourceBinding::FragmentStage;
    default:
        Q_UNREACHABLE();
        break;
    }
    return { };
}
 
void QSGMaterialShaderPrivate::prepare(QShader::Variant vertexShaderVariant)
{
    ubufBinding = -1;
    ubufSize = 0;
    ubufStages = { };
    memset(static_cast<void *>(combinedImageSamplerBindings), 0, sizeof(combinedImageSamplerBindings));
    memset(static_cast<void *>(combinedImageSamplerCount), 0, sizeof(combinedImageSamplerCount));
    vertexShader = fragmentShader = nullptr;
    masterUniformData.clear();
 
    clearCachedRendererData();
 
    for (QShader::Stage stage : { QShader::VertexStage, QShader::FragmentStage }) {
        auto it = shaderFileNames.find(stage);
        if (it != shaderFileNames.end()) {
            QString fn = *it;
            const QShader s = loadShader(*it);
            if (!s.isValid())
                continue;
            shaders[stage] = ShaderStageData(s);
            // load only once, subsequent prepare() calls will have it all in shaders already
            shaderFileNames.erase(it);
        }
    }
 
    auto vsIt = shaders.find(QShader::VertexStage);
    if (vsIt != shaders.end()) {
        vsIt->shaderVariant = vertexShaderVariant;
        vsIt->vertexInputLocations.clear();
        vsIt->qt_order_attrib_location = -1;
 
        const QShaderDescription desc = vsIt->shader.description();
        const QVector<QShaderDescription::InOutVariable> vertexInputs = desc.inputVariables();
        for (const QShaderDescription::InOutVariable &v : vertexInputs) {
            if (vertexShaderVariant == QShader::BatchableVertexShader
                && v.name == QByteArrayLiteral("_qt_order")) {
                vsIt->qt_order_attrib_location = v.location;
            } else {
                vsIt->vertexInputLocations.append(v.location);
            }
        }
 
        if (vsIt->vertexInputLocations.contains(vsIt->qt_order_attrib_location)) {
            qWarning("Vertex input clash in rewritten (batchable) vertex shader at input location %d. "
                     "Vertex shaders must avoid using this location.", vsIt->qt_order_attrib_location);
        }
    }
 
    for (auto it = shaders.begin(); it != shaders.end(); ++it) {
        const QShaderDescription desc = it->shader.description();
 
        const QVector<QShaderDescription::UniformBlock> ubufs = desc.uniformBlocks();
        const int ubufCount = ubufs.size();
        if (ubufCount > 1) {
            qWarning("Multiple uniform blocks found in shader. "
                     "This should be avoided as Qt Quick supports only one.");
        }
        for (int i = 0; i < ubufCount; ++i) {
            const QShaderDescription::UniformBlock &ubuf(ubufs[i]);
            if (ubufBinding == -1 && ubuf.binding >= 0) {
                ubufBinding = ubuf.binding;
                ubufSize = ubuf.size;
                ubufStages |= toSrbStage(it->shader.stage());
                masterUniformData.fill('\0', ubufSize);
            } else if (ubufBinding == ubuf.binding && ubuf.binding >= 0) {
                if (ubuf.size > ubufSize) {
                    ubufSize = ubuf.size;
                    masterUniformData.fill('\0', ubufSize);
                }
                ubufStages |= toSrbStage(it->shader.stage());
            } else {
                qWarning("Uniform block %s (binding %d) ignored", ubuf.blockName.constData(),
                         ubuf.binding);
            }
        }
 
        const QVector<QShaderDescription::InOutVariable> imageSamplers = desc.combinedImageSamplers();
        const int imageSamplersCount = imageSamplers.size();
        for (int i = 0; i < imageSamplersCount; ++i) {
            const QShaderDescription::InOutVariable &var(imageSamplers[i]);
 
            if (var.binding < 0)
                continue;
 
            if (var.binding < MAX_SHADER_RESOURCE_BINDINGS) {
                combinedImageSamplerBindings[var.binding] |= toSrbStage(it->shader.stage());
 
                int count = 1;
                for (int dim : var.arrayDims)
                    count *= dim;
 
                combinedImageSamplerCount[var.binding] = count;
            } else {
                qWarning("Encountered invalid combined image sampler (%s) binding %d",
                         var.name.constData(), var.binding);
            }
        }
 
        if (it.key() == QShader::VertexStage)
            vertexShader = &it.value();
        else if (it.key() == QShader::FragmentStage)
            fragmentShader = &it.value();
    }
 
    if (vertexShader && vertexShaderVariant == QShader::BatchableVertexShader && vertexShader->qt_order_attrib_location == -1)
        qWarning("No rewriter-inserted attribute found, this should not happen.");
}
 
QSGMaterialShader::QSGMaterialShader()
    : d_ptr(new QSGMaterialShaderPrivate(this))
{
}
 
QSGMaterialShader::QSGMaterialShader(QSGMaterialShaderPrivate &dd)
    : d_ptr(&dd)
{
}
 
QSGMaterialShader::~QSGMaterialShader()
{
}
 
// We have our own enum as QShader is not initially public. Internally
// everything works with QShader::Stage however. So convert.
static inline QShader::Stage toShaderStage(QSGMaterialShader::Stage stage)
{
    switch (stage) {
    case QSGMaterialShader::VertexStage:
        return QShader::VertexStage;
    case QSGMaterialShader::FragmentStage:
        return QShader::FragmentStage;
    default:
        Q_UNREACHABLE_RETURN(QShader::VertexStage);
    }
}
 
void QSGMaterialShader::setShader(Stage stage, const QShader &shader)
{
    Q_D(QSGMaterialShader);
    d->shaders[toShaderStage(stage)] = QSGMaterialShaderPrivate::ShaderStageData(shader);
}
 
void QSGMaterialShader::setShaderFileName(Stage stage, const QString &filename)
{
    Q_D(QSGMaterialShader);
    d->shaderFileNames[toShaderStage(stage)] = filename;
}
 
QSGMaterialShader::Flags QSGMaterialShader::flags() const
{
    Q_D(const QSGMaterialShader);
    return d->flags;
}
 
void QSGMaterialShader::setFlag(Flags flags, bool on)
{
    Q_D(QSGMaterialShader);
    if (on)
        d->flags |= flags;
    else
        d->flags &= ~flags;
}
 
void QSGMaterialShader::setFlags(Flags flags)
{
    Q_D(QSGMaterialShader);
    d->flags = flags;
}
 
int QSGMaterialShader::combinedImageSamplerCount(int binding) const
{
    Q_D(const QSGMaterialShader);
 
    if (binding >= 0 && binding < d->MAX_SHADER_RESOURCE_BINDINGS)
        return d->combinedImageSamplerCount[binding];
 
    return 0;
}
 
bool QSGMaterialShader::updateUniformData(RenderState &state,
                                          QSGMaterial *newMaterial,
                                          QSGMaterial *oldMaterial)
{
    Q_UNUSED(state);
    Q_UNUSED(newMaterial);
    Q_UNUSED(oldMaterial);
    return false;
}
 
void QSGMaterialShader::updateSampledImage(RenderState &state,
                                           int binding,
                                           QSGTexture **texture,
                                           QSGMaterial *newMaterial,
                                           QSGMaterial *oldMaterial)
{
    Q_UNUSED(state);
    Q_UNUSED(binding);
    Q_UNUSED(texture);
    Q_UNUSED(newMaterial);
    Q_UNUSED(oldMaterial);
}
 
bool QSGMaterialShader::updateGraphicsPipelineState(RenderState &state, GraphicsPipelineState *ps,
                                                    QSGMaterial *newMaterial, QSGMaterial *oldMaterial)
{
    Q_UNUSED(state);
    Q_UNUSED(ps);
    Q_UNUSED(newMaterial);
    Q_UNUSED(oldMaterial);
    return false;
}
 
float QSGMaterialShader::RenderState::opacity() const
{
    Q_ASSERT(m_data);
    return float(static_cast<const QSGRenderer *>(m_data)->currentOpacity());
}
 
float QSGMaterialShader::RenderState::determinant() const
{
    Q_ASSERT(m_data);
    return float(static_cast<const QSGRenderer *>(m_data)->determinant());
}
 
QMatrix4x4 QSGMaterialShader::RenderState::combinedMatrix() const
{
    Q_ASSERT(m_data);
    return static_cast<const QSGRenderer *>(m_data)->currentCombinedMatrix();
}
 
float QSGMaterialShader::RenderState::devicePixelRatio() const
{
    Q_ASSERT(m_data);
    return float(static_cast<const QSGRenderer *>(m_data)->devicePixelRatio());
}
 
QMatrix4x4 QSGMaterialShader::RenderState::modelViewMatrix() const
{
    Q_ASSERT(m_data);
    return static_cast<const QSGRenderer *>(m_data)->currentModelViewMatrix();
}
 
QMatrix4x4 QSGMaterialShader::RenderState::projectionMatrix() const
{
    Q_ASSERT(m_data);
    return static_cast<const QSGRenderer *>(m_data)->currentProjectionMatrix();
}
 
QRect QSGMaterialShader::RenderState::viewportRect() const
{
    Q_ASSERT(m_data);
    return static_cast<const QSGRenderer *>(m_data)->viewportRect();
}
 
QRect QSGMaterialShader::RenderState::deviceRect() const
{
    Q_ASSERT(m_data);
    return static_cast<const QSGRenderer *>(m_data)->deviceRect();
}
 
QByteArray *QSGMaterialShader::RenderState::uniformData()
{
    Q_ASSERT(m_data);
    return static_cast<const QSGRenderer *>(m_data)->currentUniformData();
}
 
QRhiResourceUpdateBatch *QSGMaterialShader::RenderState::resourceUpdateBatch()
{
    Q_ASSERT(m_data);
    return static_cast<const QSGRenderer *>(m_data)->currentResourceUpdateBatch();
}
 
QRhi *QSGMaterialShader::RenderState::rhi()
{
    Q_ASSERT(m_data);
    return static_cast<const QSGRenderer *>(m_data)->currentRhi();
}
 
QT_END_NAMESPACE