QRhiVertexInputAttribute Class

Describes a single vertex input element. 更多...

头：	#include <rhi/qrhi.h>
CMake:	find_package(Qt6 REQUIRED COMPONENTS Gui) target_link_libraries(mytarget PRIVATE Qt6::GuiPrivate)
qmake:	QT += gui-private
Since:	Qt 6.6

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公共类型

enum	格式 { Float4, Float3, Float2, Float, UNormByte4, …, SShort }

公共函数

	QRhiVertexInputAttribute ()
	QRhiVertexInputAttribute (int binding , int location , QRhiVertexInputAttribute::Format format , quint32 offset , int matrixSlice = -1)
int	binding () const
QRhiVertexInputAttribute::Format	format () const
int	location () const
int	matrixSlice () const
quint32	offset () const
void	setBinding (int b )
void	setFormat (QRhiVertexInputAttribute::Format f )
void	setLocation (int loc )
void	setMatrixSlice (int slice )
void	setOffset (quint32 ofs )

相关非成员

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

详细描述

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

注意： 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:

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);
					

注意： This is a RHI API with limited compatibility guarantees, see QRhi 了解细节。

另请参阅 QRhiCommandBuffer::setVertexInput ().

成员类型文档编制

enum QRhiVertexInputAttribute:: 格式

Specifies the type of the element data.

常量	值	描述
QRhiVertexInputAttribute::Float4	0	Four component float vector
QRhiVertexInputAttribute::Float3	1	Three component float vector
QRhiVertexInputAttribute::Float2	2	Two component float vector
QRhiVertexInputAttribute::Float	3	Float
QRhiVertexInputAttribute::UNormByte4	4	Four component normalized unsigned byte vector
QRhiVertexInputAttribute::UNormByte2	5	Two component normalized unsigned byte vector
QRhiVertexInputAttribute::UNormByte	6	Normalized unsigned byte
QRhiVertexInputAttribute::UInt4	7	Four component unsigned integer vector
QRhiVertexInputAttribute::UInt3	8	Three component unsigned integer vector
QRhiVertexInputAttribute::UInt2	9	Two component unsigned integer vector
QRhiVertexInputAttribute::UInt	10	Unsigned integer
QRhiVertexInputAttribute::SInt4	11	Four component signed integer vector
QRhiVertexInputAttribute::SInt3	12	Three component signed integer vector
QRhiVertexInputAttribute::SInt2	13	Two component signed integer vector
QRhiVertexInputAttribute::SInt	14	Signed integer
QRhiVertexInputAttribute::Half4	15	Four component half precision (16 bit) float vector
QRhiVertexInputAttribute::Half3	16	Three component half precision (16 bit) float vector
QRhiVertexInputAttribute::Half2	17	Two component half precision (16 bit) float vector
QRhiVertexInputAttribute::Half	18	Half precision (16 bit) float
QRhiVertexInputAttribute::UShort4	19	Four component unsigned short (16 bit) integer vector
QRhiVertexInputAttribute::UShort3	20	Three component unsigned short (16 bit) integer vector
QRhiVertexInputAttribute::UShort2	21	Two component unsigned short (16 bit) integer vector
QRhiVertexInputAttribute::UShort	22	Unsigned short (16 bit) integer
QRhiVertexInputAttribute::SShort4	23	Four component signed short (16 bit) integer vector
QRhiVertexInputAttribute::SShort3	24	Three component signed short (16 bit) integer vector
QRhiVertexInputAttribute::SShort2	25	Two component signed short (16 bit) integer vector
QRhiVertexInputAttribute::SShort	26	Signed short (16 bit) integer

注意： Support for half precision floating point attributes is indicated at run time by the QRhi::Feature::HalfAttributes feature flag.

注意： Direct3D 11/12 supports 16 bit input attributes, but does not support the Half3, UShort3 or SShort3 types. The D3D backends pass through Half3 as Half4, UShort3 as UShort4, and SShort3 as SShort4. To ensure cross platform compatibility, 16 bit inputs should be padded to 8 bytes.

成员函数文档编制

[constexpr noexcept] QRhiVertexInputAttribute:: QRhiVertexInputAttribute ()

Constructs a default vertex input attribute description.

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

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

int QRhiVertexInputAttribute:: binding () const

Returns the binding point index.

另请参阅 setBinding ().

QRhiVertexInputAttribute::Format QRhiVertexInputAttribute:: format () const

Returns the format of the vertex input element.

另请参阅 setFormat ().

int QRhiVertexInputAttribute:: location () const

Returns the location of the vertex input element.

另请参阅 setLocation ().

int QRhiVertexInputAttribute:: matrixSlice () const

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

另请参阅 setMatrixSlice ().

quint32 QRhiVertexInputAttribute:: offset () const

Returns the byte offset for the input element.

另请参阅 setOffset ().

void QRhiVertexInputAttribute:: setBinding ( int b )

Sets the binding point index to b . By default this is set to 0.

另请参阅 binding ().

void QRhiVertexInputAttribute:: setFormat ( QRhiVertexInputAttribute::Format f )

Sets the format of the vertex input element to f . By default this is set to Float4.

另请参阅 format ().

void QRhiVertexInputAttribute:: setLocation ( int loc )

Sets the location of the vertex input element to loc . By default this is set to 0.

另请参阅 location ().

void QRhiVertexInputAttribute:: setMatrixSlice ( int slice )

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.

另请参阅 matrixSlice ().

void QRhiVertexInputAttribute:: setOffset ( quint32 ofs )

Sets the byte offset for the input element to ofs .

另请参阅 offset ().

相关非成员

[noexcept] size_t qHash (const QRhiVertexInputAttribute & key , size_t seed = 0)

返回哈希值为 key ，使用 seed 做计算种子。

[noexcept] bool operator!= (const QRhiVertexInputAttribute & a , const QRhiVertexInputAttribute & b )

返回 false if the values in the two QRhiVertexInputAttribute 对象 a and b 相等；否则返回 true .

[noexcept] bool operator== (const QRhiVertexInputAttribute & a , const QRhiVertexInputAttribute & b )

返回 true if the values in the two QRhiVertexInputAttribute 对象 a and b 相等。

内容

1. 公共类型

2. 公共函数

3. 相关非成员

4. 详细描述