QShaderProgram Class
class Qt3DRender::QShaderProgramEncapsulates a Shader Program. More...
| Header: | #include <QShaderProgram> |
| CMake: | find_package(Qt6 REQUIRED COMPONENTS 3drender) target_link_libraries(mytarget PRIVATE Qt6::3drender) |
| qmake: | QT += 3drender |
| Instantiated By: | ShaderProgram |
| Inherits: | Qt3DCore::QNode |
Public Types
| enum | Format { GLSL, SPIRV } |
| enum | ShaderType { Vertex, Fragment, TessellationControl, TessellationEvaluation, Geometry, Compute } |
| enum | Status { NotReady, Ready, Error } |
Properties
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Public Functions
| QByteArray | computeShaderCode() const |
| Qt3DRender::QShaderProgram::Format | format() const |
| QByteArray | fragmentShaderCode() const |
| QByteArray | geometryShaderCode() const |
| QString | log() const |
| void | setFormat(Qt3DRender::QShaderProgram::Format format) |
| void | setShaderCode(Qt3DRender::QShaderProgram::ShaderType type, const QByteArray &shaderCode) |
| QByteArray | shaderCode(Qt3DRender::QShaderProgram::ShaderType type) const |
| Qt3DRender::QShaderProgram::Status | status() const |
| QByteArray | tessellationControlShaderCode() const |
| QByteArray | tessellationEvaluationShaderCode() const |
| QByteArray | vertexShaderCode() const |
Public Slots
| void | setComputeShaderCode(const QByteArray &computeShaderCode) |
| void | setFragmentShaderCode(const QByteArray &fragmentShaderCode) |
| void | setGeometryShaderCode(const QByteArray &geometryShaderCode) |
| void | setTessellationControlShaderCode(const QByteArray &tessellationControlShaderCode) |
| void | setTessellationEvaluationShaderCode(const QByteArray &tessellationEvaluationShaderCode) |
| void | setVertexShaderCode(const QByteArray &vertexShaderCode) |
Signals
| void | computeShaderCodeChanged(const QByteArray &computeShaderCode) |
| void | formatChanged(Qt3DRender::QShaderProgram::Format format) |
| void | fragmentShaderCodeChanged(const QByteArray &fragmentShaderCode) |
| void | geometryShaderCodeChanged(const QByteArray &geometryShaderCode) |
| void | logChanged(const QString &log) |
| void | statusChanged(Qt3DRender::QShaderProgram::Status status) |
| void | tessellationControlShaderCodeChanged(const QByteArray &tessellationControlShaderCode) |
| void | tessellationEvaluationShaderCodeChanged(const QByteArray &tessellationEvaluationShaderCode) |
| void | vertexShaderCodeChanged(const QByteArray &vertexShaderCode) |
Static Public Members
| QByteArray | loadSource(const QUrl &sourceUrl) |
Detailed Description
A shader program consists of several different shaders, such as vertex and fragment shaders.
Qt3D will automatically populate a set of default uniforms if they are encountered during the shader instrospection phase.
| Default Uniform | Associated Qt3D Parameter name | GLSL declaration |
|---|---|---|
| ModelMatrix | modelMatrix | uniform mat4 modelMatrix; |
| ViewMatrix | viewMatrix | uniform mat4 viewMatrix; |
| ProjectionMatrix | projectionMatrix | uniform mat4 projectionMatrix; |
| ModelViewMatrix | modelView | uniform mat4 modelView; |
| ViewProjectionMatrix | viewProjectionMatrix | uniform mat4 viewProjectionMatrix; |
| ModelViewProjectionMatrix | modelViewProjection mvp | uniform mat4 modelViewProjection; uniform mat4 mvp; |
| InverseModelMatrix | inverseModelMatrix | uniform mat4 inverseModelMatrix; |
| InverseViewMatrix | inverseViewMatrix | uniform mat4 inverseViewMatrix; |
| InverseProjectionMatrix | inverseProjectionMatrix | uniform mat4 inverseProjectionMatrix; |
| InverseModelViewMatrix | inverseModelView | uniform mat4 inverseModelView; |
| InverseViewProjectionMatrix | inverseViewProjectionMatrix | uniform mat4 inverseViewProjectionMatrix; |
| InverseModelViewProjectionMatrix | inverseModelViewProjection | uniform mat4 inverseModelViewProjection; |
| ModelNormalMatrix | modelNormalMatrix | uniform mat3 modelNormalMatrix; |
| ModelViewNormalMatrix | modelViewNormal | uniform mat3 modelViewNormal; |
| ViewportMatrix | viewportMatrix | uniform mat4 viewportMatrix; |
| InverseViewportMatrix | inverseViewportMatrix | uniform mat4 inverseViewportMatrix; |
| AspectRatio (surface width / surface height) | aspectRatio | uniform float aspectRatio; |
| Exposure | exposure | uniform float exposure; |
| Gamma | gamma | uniform float gamma; |
| Time (in nano seconds) | time | uniform float time; |
| EyePosition | eyePosition | uniform vec3 eyePosition; |
| SkinningPalette | skinningPalette[0] | const int maxJoints = 100; uniform mat4 skinningPalette[maxJoints]; |
RHI Support
When writing GLSL 450 shader code to use with Qt 3D's RHI backend, the default uniforms will be provided as 2 uniform buffer objects.
The binding locations for these is set to bindings 0 for RenderView uniforms and 1 for Command uniforms.
#version 450 core
layout(location = 0) in vec3 vertexPosition;
layout(std140, binding = 0) uniform qt3d_render_view_uniforms {
mat4 viewMatrix;
mat4 projectionMatrix;
mat4 uncorrectedProjectionMatrix;
mat4 clipCorrectionMatrix;
mat4 viewProjectionMatrix;
mat4 inverseViewMatrix;
mat4 inverseProjectionMatrix;
mat4 inverseViewProjectionMatrix;
mat4 viewportMatrix;
mat4 inverseViewportMatrix;
vec4 textureTransformMatrix;
vec3 eyePosition;
float aspectRatio;
float gamma;
float exposure;
float time;
float yUpInNDC;
float yUpInFBO;
};
layout(std140, binding = 1) uniform qt3d_command_uniforms {
mat4 modelMatrix;
mat4 inverseModelMatrix;
mat4 modelViewMatrix;
mat3 modelNormalMatrix;
mat4 inverseModelViewMatrix;
mat4 modelViewProjection;
mat4 inverseModelViewProjectionMatrix;
};
void main()
{
gl_Position = (projectionMatrix * viewMatrix * modelMatrix * vertexPosition);
}For user defined uniform buffer object, use binding starting at 2 or auto to let Qt 3D work out the binding automatically. Make sure to remain consistent between the different shader stages.
#version 450 core
layout(std140, binding = auto) uniform my_uniforms {
vec4 myColor;
};
layout(location=0) out vec4 fragColor;
void main()
{
fragColor = myColor;
}There is no change involved when it comes to feeding values to uniforms.
For the above example, setting myColor could be done with:
QParameter *parameter = new QParameter();
parameter->setName("myColor");
parameter->setValue(QVariant::fromValue(QColor(Qt::blue)));Textures still have to be defined as standalone uniforms.
#version 450 core
layout(binding=0) uniform sampler2D source;
layout(location=0) out vec4 fragColor;
void main()
{
fragColor = texture(source, vec2(0.5, 0.5));
}Member Type Documentation
enum QShaderProgram::Format
This enum identifies the format of the shader code used.
| Constant | Value | Description |
|---|---|---|
Qt3DRender::QShaderProgram::GLSL | 0 | OpenGL |
Qt3DRender::QShaderProgram::SPIRV | 1 | Vulkan, OpenGL 5 |
enum QShaderProgram::ShaderType
This enum identifies the type of shader used.
| Constant | Value | Description |
|---|---|---|
Qt3DRender::QShaderProgram::Vertex | 0 | Vertex shader |
Qt3DRender::QShaderProgram::Fragment | 1 | Fragment shader |
Qt3DRender::QShaderProgram::TessellationControl | 2 | Tesselation control shader |
Qt3DRender::QShaderProgram::TessellationEvaluation | 3 | Tesselation evaluation shader |
Qt3DRender::QShaderProgram::Geometry | 4 | Geometry shader |
Qt3DRender::QShaderProgram::Compute | 5 | Compute shader |
enum QShaderProgram::Status
This enum identifies the status of shader used.
| Constant | Value | Description |
|---|---|---|
Qt3DRender::QShaderProgram::NotReady | 0 | The shader hasn't been compiled and linked yet |
Qt3DRender::QShaderProgram::Ready | 1 | The shader was successfully compiled |
Qt3DRender::QShaderProgram::Error | 2 | An error occurred while compiling the shader |
Property Documentation
computeShaderCode : QByteArray
Holds the compute shader code used by this shader program.
Access functions:
| QByteArray | computeShaderCode() const |
| void | setComputeShaderCode(const QByteArray &computeShaderCode) |
Notifier signal:
| void | computeShaderCodeChanged(const QByteArray &computeShaderCode) |
format : Format
Holds the format of the code provided on the ShaderProgram. The default is ShaderProgram.GLSL
Access functions:
| Qt3DRender::QShaderProgram::Format | format() const |
| void | setFormat(Qt3DRender::QShaderProgram::Format format) |
Notifier signal:
| void | formatChanged(Qt3DRender::QShaderProgram::Format format) |
fragmentShaderCode : QByteArray
Holds the fragment shader code used by this shader program.
Access functions:
| QByteArray | fragmentShaderCode() const |
| void | setFragmentShaderCode(const QByteArray &fragmentShaderCode) |
Notifier signal:
| void | fragmentShaderCodeChanged(const QByteArray &fragmentShaderCode) |
geometryShaderCode : QByteArray
Holds the geometry shader code used by this shader program.
Access functions:
| QByteArray | geometryShaderCode() const |
| void | setGeometryShaderCode(const QByteArray &geometryShaderCode) |
Notifier signal:
| void | geometryShaderCodeChanged(const QByteArray &geometryShaderCode) |
[read-only] log : const QString
Holds the log of the current shader program. This is useful to diagnose a compilation failure of the shader program.
Access functions:
| QString | log() const |
Notifier signal:
| void | logChanged(const QString &log) |
[read-only] status : const Status
Holds the status of the current shader program.
Access functions:
| Qt3DRender::QShaderProgram::Status | status() const |
Notifier signal:
| void | statusChanged(Qt3DRender::QShaderProgram::Status status) |
tessellationControlShaderCode : QByteArray
Holds the tesselation control shader code used by this shader program.
Access functions:
| QByteArray | tessellationControlShaderCode() const |
| void | setTessellationControlShaderCode(const QByteArray &tessellationControlShaderCode) |
Notifier signal:
| void | tessellationControlShaderCodeChanged(const QByteArray &tessellationControlShaderCode) |
tessellationEvaluationShaderCode : QByteArray
Holds the tesselation evaluation shader code used by this shader program.
Access functions:
| QByteArray | tessellationEvaluationShaderCode() const |
| void | setTessellationEvaluationShaderCode(const QByteArray &tessellationEvaluationShaderCode) |
Notifier signal:
| void | tessellationEvaluationShaderCodeChanged(const QByteArray &tessellationEvaluationShaderCode) |
vertexShaderCode : QByteArray
Holds the vertex shader code used by this shader program.
Access functions:
| QByteArray | vertexShaderCode() const |
| void | setVertexShaderCode(const QByteArray &vertexShaderCode) |
Notifier signal:
| void | vertexShaderCodeChanged(const QByteArray &vertexShaderCode) |
Member Function Documentation
[static invokable] QByteArray QShaderProgram::loadSource(const QUrl &sourceUrl)
Returns the shader code loaded from sourceUrl.
Note: This function can be invoked via the meta-object system and from QML. See Q_INVOKABLE.
void QShaderProgram::setShaderCode(Qt3DRender::QShaderProgram::ShaderType type, const QByteArray &shaderCode)
Sets the shader code for type of shader to the shaderCode.
See also shaderCode().
QByteArray QShaderProgram::shaderCode(Qt3DRender::QShaderProgram::ShaderType type) const
Returns the shader code for type.
See also setShaderCode().
Qt3DRender::QShaderProgram::Status QShaderProgram::status() const
Returns the status of the current shader program.
Note: Getter function for property status.
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