QRhiVertexInputAttribute Class
Describes a single vertex input element. More...
Header: | #include <QRhiVertexInputAttribute> |
CMake: | find_package(Qt6 REQUIRED COMPONENTS Gui) target_link_libraries(mytarget PRIVATE Qt6::Gui) |
qmake: | QT += gui |
Since: | Qt 6.6 |
Public Types
enum | Format { Float4, Float3, Float2, Float, UNormByte4, …, Half } |
Public Functions
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) |
Related Non-Members
size_t | qHash(const QRhiVertexInputAttribute &v, size_t seed = 0) |
bool | operator!=(const QRhiVertexInputAttribute &a, const QRhiVertexInputAttribute &b) |
bool | operator==(const QRhiVertexInputAttribute &a, const QRhiVertexInputAttribute &b) |
Detailed Description
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:
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 QRhi for details.
See also QRhiCommandBuffer::setVertexInput().
Member Type Documentation
enum QRhiVertexInputAttribute::Format
Specifies the type of the element data.
Constant | Value | Description |
---|---|---|
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 |
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.
Member Function Documentation
[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, 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.
int QRhiVertexInputAttribute::binding() const
Returns the binding point index.
See also setBinding().
QRhiVertexInputAttribute::Format QRhiVertexInputAttribute::format() const
Returns the format of the vertex input element.
See also setFormat().
int QRhiVertexInputAttribute::location() const
Returns the location of the vertex input element.
See also 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.
See also setMatrixSlice().
quint32 QRhiVertexInputAttribute::offset() const
Returns the byte offset for the input element.
See also setOffset().
void QRhiVertexInputAttribute::setBinding(int b)
Sets the binding point index to b. By default this is set to 0.
See also binding().
void QRhiVertexInputAttribute::setFormat(QRhiVertexInputAttribute::Format f)
Sets the format of the vertex input element to f. By default this is set to Float4.
See also format().
void QRhiVertexInputAttribute::setLocation(int loc)
Sets the location of the vertex input element to loc. By default this is set to 0.
See also 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.
See also matrixSlice().
void QRhiVertexInputAttribute::setOffset(quint32 ofs)
Sets the byte offset for the input element to ofs.
See also offset().
Related Non-Members
[noexcept]
size_t qHash(const QRhiVertexInputAttribute &v, size_t seed = 0)
Returns the hash value for v, using seed to seed the calculation.
[noexcept]
bool operator!=(const QRhiVertexInputAttribute &a, const QRhiVertexInputAttribute &b)
Returns false
if the values in the two QRhiVertexInputAttribute objects a and b are equal; otherwise returns true
.
[noexcept]
bool operator==(const QRhiVertexInputAttribute &a, const QRhiVertexInputAttribute &b)
Returns true
if the values in the two QRhiVertexInputAttribute objects a and b are equal.
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