QRhiVertexInputAttribute Class Reference

\inmodule QtGui More...

#include <qrhi.h>

Collaboration diagram for QRhiVertexInputAttribute:

Public Types
enum	Format {   Float4 , Float3 , Float2 , Float ,   UNormByte4 , UNormByte2 , UNormByte , UInt4 ,   UInt3 , UInt2 , UInt , SInt4 ,   SInt3 , SInt2 , SInt , Half4 ,   Half3 , Half2 , Half }
	Specifies the type of the element data. More...

Public Member Functions
	QRhiVertexInputAttribute ()=default
	Constructs a default vertex input attribute description.
	QRhiVertexInputAttribute (int binding, int location, Format format, quint32 offset, int matrixSlice=-1)
	Constructs a vertex input attribute description with the specified binding number, location, format, and offset.
int	binding () const
void	setBinding (int b)
	Sets the binding point index to b.
int	location () const
void	setLocation (int loc)
	Sets the location of the vertex input element to loc.
Format	format () const
void	setFormat (Format f)
	Sets the format of the vertex input element to f.
quint32	offset () const
void	setOffset (quint32 ofs)
	Sets the byte offset for the input element to ofs.
int	matrixSlice () const
void	setMatrixSlice (int slice)
	Sets the matrix slice.

Friends
bool	operator== (const QRhiVertexInputAttribute &a, const QRhiVertexInputAttribute &b) noexcept
bool	operator!= (const QRhiVertexInputAttribute &a, const QRhiVertexInputAttribute &b) noexcept
size_t	qHash (const QRhiVertexInputAttribute &v, size_t seed=0) noexcept

Detailed Description

\inmodule QtGui

Since

6.6

Describes a single vertex input element.

The members specify the binding number, location, format, and offset for a single vertex input element.

Note

For HLSL it is assumed that the vertex shader translated from SPIR-V uses {TEXCOORD<location>} as the semantic for each input. Hence no separate semantic name and index.

As an example, assume a vertex shader with the following inputs:

\badcode layout(location = 0) in vec4 position; layout(location = 1) in vec2 texcoord;

Now let's assume that we have 3 component vertex positions {(x, y, z)} and 2 component texture coordinates {(u, v)} are provided in a non-interleaved format in a buffer (or separate buffers even). Once two bindings are defined, the attributes could be specified as:

QRhiVertexInputLayout inputLayout;
inputLayout.setBindings({
    { 3 * sizeof(float) },
    { 2 * sizeof(float) }
});
inputLayout.setAttributes({
    { 0, 0, QRhiVertexInputAttribute::Float3, 0 },
    { 1, 1, QRhiVertexInputAttribute::Float2, 0 }
});

Once a graphics pipeline with this vertex input layout is bound, the vertex inputs could be set up like the following for drawing a cube with 36 vertices, assuming we have a single buffer with first the positions and then the texture coordinates:

const QRhiCommandBuffer::VertexInput vbufBindings[] = {
    { cubeBuf, 0 },
    { cubeBuf, 36 * 3 * sizeof(float) }
};
cb->setVertexInput(0, 2, vbufBindings);

When working with interleaved data, there will typically be just one binding, with multiple attributes referring to that same buffer binding point:

QRhiVertexInputLayout inputLayout;
inputLayout.setBindings({
    { 5 * sizeof(float) }
});
inputLayout.setAttributes({
    { 0, 0, QRhiVertexInputAttribute::Float3, 0 },
    { 0, 1, QRhiVertexInputAttribute::Float2, 3 * sizeof(float) }
});

and then:

const QRhiCommandBuffer::VertexInput vbufBinding(interleavedCubeBuf, 0);
cb->setVertexInput(0, 1, &vbufBinding);

Note

This is a RHI API with limited compatibility guarantees, see \l QRhi for details.

See also

QRhiCommandBuffer::setVertexInput()

Definition at line 231 of file qrhi.h.

Member Enumeration Documentation

Format

enum QRhiVertexInputAttribute::Format

Specifies the type of the element data.

\value Float4 Four component float vector \value Float3 Three component float vector \value Float2 Two component float vector \value Float Float \value UNormByte4 Four component normalized unsigned byte vector \value UNormByte2 Two component normalized unsigned byte vector \value UNormByte Normalized unsigned byte \value UInt4 Four component unsigned integer vector \value UInt3 Three component unsigned integer vector \value UInt2 Two component unsigned integer vector \value UInt Unsigned integer \value SInt4 Four component signed integer vector \value SInt3 Three component signed integer vector \value SInt2 Two component signed integer vector \value SInt Signed integer \value Half4 Four component half precision (16 bit) float vector \value Half3 Three component half precision (16 bit) float vector \value Half2 Two component half precision (16 bit) float vector \value Half Half precision (16 bit) float

Note

Support for half precision floating point attributes is indicated at run time by the QRhi::Feature::HalfAttributes feature flag. Note that Direct3D 11/12 supports half input attributes, but does not support the Half3 type. The D3D backends pass through Half3 as Half4. To ensure cross platform compatibility, Half3 inputs should be padded to 8 bytes.

Enumerator
Float4
Float3
Float2
Float
UNormByte4
UNormByte2
UNormByte
UInt4
UInt3
UInt2
UInt
SInt4
SInt3
SInt2
SInt
Half4
Half3
Half2
Half

Definition at line 234 of file qrhi.h.

Constructor & Destructor Documentation

QRhiVertexInputAttribute() [1/2]

QRhiVertexInputAttribute::QRhiVertexInputAttribute ( )

default

Constructs a default vertex input attribute description.

QRhiVertexInputAttribute() [2/2]

QRhiVertexInputAttribute::QRhiVertexInputAttribute	(	int	binding,
		int	location,
		Format	format,
		quint32	offset,
		int	matrixSlice = -1
	)

Constructs a vertex input attribute description with the specified binding number, location, format, and offset.

matrixSlice should be -1 except when this attribute corresponds to a row or column of a matrix (for example, a 4x4 matrix becomes 4 vec4s, consuming 4 consecutive vertex input locations), in which case it is the index of the row or column. {location - matrixSlice} must always be equal to the location for the first row or column of the unrolled matrix.

Definition at line 1684 of file qrhi.cpp.

Member Function Documentation

binding()

int QRhiVertexInputAttribute::binding ( ) const

inline

Returns

the binding point index.

Definition at line 259 of file qrhi.h.

format()

QRhiVertexInputAttribute::Format QRhiVertexInputAttribute::format ( ) const

inline

Returns

the format of the vertex input element.

Definition at line 265 of file qrhi.h.

location()

int QRhiVertexInputAttribute::location ( ) const

inline

Returns

the location of the vertex input element.

Definition at line 262 of file qrhi.h.

matrixSlice()

int QRhiVertexInputAttribute::matrixSlice ( ) const

inline

Returns

the matrix slice if the input element corresponds to a row or column of a matrix, or -1 if not relevant.

Definition at line 271 of file qrhi.h.

offset()

quint32 QRhiVertexInputAttribute::offset ( ) const

inline

Returns

the byte offset for the input element.

Definition at line 268 of file qrhi.h.

setBinding()

void QRhiVertexInputAttribute::setBinding ( int  b )

inline

Sets the binding point index to b.

By default this is set to 0.

Definition at line 260 of file qrhi.h.

setFormat()

void QRhiVertexInputAttribute::setFormat ( Format  f )

inline

Sets the format of the vertex input element to f.

By default this is set to Float4.

Definition at line 266 of file qrhi.h.

setLocation()

void QRhiVertexInputAttribute::setLocation ( int  loc )

inline

Sets the location of the vertex input element to loc.

By default this is set to 0.

Definition at line 263 of file qrhi.h.

setMatrixSlice()

void QRhiVertexInputAttribute::setMatrixSlice ( int  slice )

inline

Sets the matrix slice.

By default this is set to -1, and should be set to a >= 0 value only when this attribute corresponds to a row or column of a matrix (for example, a 4x4 matrix becomes 4 vec4s, consuming 4 consecutive vertex input locations), in which case it is the index of the row or column. {location - matrixSlice} must always be equal to the location for the first row or column of the unrolled matrix.

Definition at line 272 of file qrhi.h.

setOffset()

void QRhiVertexInputAttribute::setOffset ( quint32  ofs )

inline

Sets the byte offset for the input element to ofs.

Definition at line 269 of file qrhi.h.

Friends And Related Symbol Documentation

operator!=

bool QRhiVertexInputAttribute::operator!= ( const QRhiVertexInputAttribute &  a, const QRhiVertexInputAttribute &  b  )

friend

Returns

false if the values in the two QRhiVertexInputAttribute objects a and b are equal; otherwise returns true.

Definition at line 290 of file qrhi.h.

operator==

bool QRhiVertexInputAttribute::operator== ( const QRhiVertexInputAttribute &  a, const QRhiVertexInputAttribute &  b  )

friend

Returns

true if the values in the two QRhiVertexInputAttribute objects a and b are equal.

Definition at line 281 of file qrhi.h.

qHash

size_t QRhiVertexInputAttribute::qHash ( const QRhiVertexInputAttribute &  v, size_t  seed = 0  )

friend

Returns

the hash value for v, using seed to seed the calculation.

Definition at line 295 of file qrhi.h.

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The documentation for this class was generated from the following files:

• qtbase/src/gui/rhi/qrhi.h
• qtbase/src/gui/rhi/qrhi.cpp