Shader which has instanced values for uniforms and other GL state. More...

Inheritance diagram for InstancedShader:

Public Member Functions
	InstancedShader (const ShaderPtr &sharedShader)
	Create an InstancedShader which references a shader Shader. More...

const ShaderPtr &	getSharedShader () const
	Returns the Shader that is shared among instances. More...

virtual bool	isCurrent () const override
	Returns whether or not this instance is bound. More...

virtual bool	isValid () const override
	Returns whether or not this shader is valid (compiled and linked) and can be used for rendering. More...

virtual bool	isCompiled () const override
	Returns whether or not this shader has been processed for compilation. More...

virtual GLuint	getProgramId () const override
	Returns the GL program id for this shader. More...

virtual void	begin () override
	Binds this shader, and sets uniforms and other GL state associated with this instance. More...

virtual void	end () override
	Unbinds this shader if bound by a corresponding call to begin(). More...

virtual void	compile () override
	Compiles this shader, resulting in the compilation of the shared Shader if necessary. More...

virtual std::string	getErrorLog () const override
	Retrieves the string describing compilation errors, if the call to compile() failed and isValid() is `false`. More...

virtual int	getAttributeLocation (int index) const override
	Returns the location of an indexed Attribute. More...

virtual int	getUniformLocation (int index) const override
	Returns the location of an indexed uniform. More...

void	setIndexedTexture (int index, int stage, const TexturePtr &value, TexturePtr *stateValue)
	Set the indexed texture for this instance at the given `index`. More...

Public Member Functions inherited from Shader
	Shader (const AttributeSetPtr &attributes, const std::vector< std::string > &uniformNames)
	Construct a Shader with the given list of attributes and uniforms. More...

const AttributeSetPtr &	getAttributes () const
	Returns the list of indexed Attributes for this shader, as an AttributeSet. More...

const std::vector< std::string > &	getUniformNames () const
	Returns the list of indexed uniforms. More...

void	setIndexedUniform1f (int index, bool global, float value, float *stateValue)
	Set the value of a float scalar uniform at the given `index`. More...

void	setIndexedUniform2f (int index, bool global, const Vector2 &value, Vector2 *stateValue)
	Set the value of a 2D float vector uniform at the given `index`. More...

void	setIndexedUniform3f (int index, bool global, float value1, float value2, float value3, float *stateValue)
	Set the value of a 3D float vector uniform at the given `index`. More...

void	setIndexedUniform4f (int index, bool global, float value1, float value2, float value3, float value4, float *stateValue)
	Set the value of a 4D float vector uniform at the given `index`. More...

void	setIndexedUniform1i (int index, bool global, int value, int *stateValue)
	Set the value of an integer scalar uniform at the given `index`. More...

void	setIndexedUniformMatrix4f (int index, bool global, bool transpose, const Matrix4 &value, Matrix4 *stateValue)
	Set the value of a 4x4 float matrix uniform at the given `index`. More...

Protected Member Functions
virtual void	updateState ()
	Update state in response to this instance getting bound. More...

Detailed Description

Shader which has instanced values for uniforms and other GL state.

All instances of the same shader share the same underlying shader program, but will upload new values for uniforms specific to that instance when selected for rendering. Because each instance stores a copy of its own state, instanced shaders can effectively be used as simple "materials".

Note: The setIndexed family of methods (many inherited from Shader) are helpers to implement subclasses of InstancedShaders. The value to set is copied into stateValue. This should normally be a member variable of the InstancedShader subclass. If the instance is currently bound, the state change then happens immediately. If the instance is not bound, the saved off value will get set during the next call to begin(). This is implemented by the subclass by overriding updateStates() which is called by begin().; Global uniforms are those that are uninstanced and shared between all instances. These will always be set immediately, regardless of whether or not they are currently bound. They also do not require that their value be saved off to a member variable. An example of a global uniform might be a projection matrix. There might only ever need to be one value for all instances if there is only one camera. An example of an instanced uniform might be color. All instances of the shader would be able to specify their own unique colors.

Constructor & Destructor Documentation

InstancedShader::InstancedShader ( const ShaderPtr & sharedShader )

explicit

Create an InstancedShader which references a shader Shader.

Parameters

sharedShader Shader that is shared among instances, and that will receive specific uniform values when this instance is bound

Member Function Documentation

virtual void InstancedShader::begin ( )

overridevirtual

Binds this shader, and sets uniforms and other GL state associated with this instance.

Shader uniforms and GL state are updated through a call to updateState(). Multiple calls to begin have no effect.

Implements Shader.

virtual void InstancedShader::compile ( )

overridevirtual

Compiles this shader, resulting in the compilation of the shared Shader if necessary.

Implements Shader.

virtual void InstancedShader::end ( )

overridevirtual

Unbinds this shader if bound by a corresponding call to begin().

If the shader is not currently selected, this call has no effect.

Implements Shader.

virtual int InstancedShader::getAttributeLocation ( int index ) const

overridevirtual

Returns the location of an indexed Attribute.

Indexed attributes are those that are named in the AttributeSet provided to the shader's constructor.

Parameters

index Index into the list of attributes

Implements Shader.

virtual std::string InstancedShader::getErrorLog ( ) const

overridevirtual

Retrieves the string describing compilation errors, if the call to compile() failed and isValid() is false.

Returns: String describing compilation errors

Implements Shader.

virtual GLuint InstancedShader::getProgramId ( ) const

overridevirtual

Returns the GL program id for this shader.

Implements Shader.

const ShaderPtr& InstancedShader::getSharedShader ( ) const

inline

Returns the Shader that is shared among instances.

virtual int InstancedShader::getUniformLocation ( int index ) const

overridevirtual

Returns the location of an indexed uniform.

Indexed uniforms are those that are named in the list of uniforms provided to the shader's constructor.

Parameters

index Index into the list of uniforms

Implements Shader.

virtual bool InstancedShader::isCompiled ( ) const

overridevirtual

Returns whether or not this shader has been processed for compilation.

Note: This does not indicate whether compilation succeeded. To test for success, use isValid().

Implements Shader.

virtual bool InstancedShader::isCurrent ( ) const

overridevirtual

Returns whether or not this instance is bound.

Implements Shader.

virtual bool InstancedShader::isValid ( ) const

overridevirtual

Returns whether or not this shader is valid (compiled and linked) and can be used for rendering.

Implements Shader.

void InstancedShader::setIndexedTexture	(	int	index,
		int	stage,
		const TexturePtr &	value,
		TexturePtr *	stateValue
	)

Set the indexed texture for this instance at the given index.

See InstancedShader for details on the setIndexed family of methods.

Parameters

index	Index of the indexed texture
stage	Texture stage to bind the texture to
value	Texture to bind
stateValue	Memory to save off state to, or `nullptr` if state should not be saved

virtual void InstancedShader::updateState ( )

protectedvirtual

Update state in response to this instance getting bound.

Implemented by subclasses. Implementers should update state such as uniforms that have values specific to this instance. The setIndexed family of methods can be used, with the stateValue parameters set to nullptr, and the value parameter set to the previously saved off value.

Reimplemented in TerrainShader, and SpriteShader.

Public Member Functions

Protected Member Functions

Detailed Description

Constructor & Destructor Documentation

Member Function Documentation