Shader Class Reference

Shader program abstract base class. More...

Inheritance diagram for Shader:

Public Member Functions
	Shader (const AttributeSetPtr &attributes, const std::vector< std::string > &uniformNames)
	Construct a Shader with the given list of attributes and uniforms. More...
virtual bool	isCurrent () const =0
	Returns whether or not this shader is bound. More...
virtual bool	isValid () const =0
	Returns whether or not this shader is valid (compiled and linked) and can be used for rendering. More...
virtual bool	isCompiled () const =0
	Returns whether or not this shader has been processed for compilation. More...
virtual GLuint	getProgramId () const =0
	Returns the GL program id for this shader. More...
virtual void	begin ()=0
	Binds this shader, updating state as necessary. More...
virtual void	end ()=0
	Unbinds this shader if bound by a corresponding call to begin(). More...
virtual void	compile ()=0
	Compiles this shader, if not already compiled. More...
virtual std::string	getErrorLog () const =0
	Retrieves the string describing compilation errors, if the call to compile() failed and isValid() is false. 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...
virtual int	getAttributeLocation (int index) const =0
	Returns the location of an indexed Attribute. More...
virtual int	getUniformLocation (int index) const =0
	Returns the location of an indexed uniform. 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...

Detailed Description

Shader program abstract base class.

This class is a wrapper around a GL program, with the added concept of indexed attributes and uniforms. Indexed attributes and uniforms allow attributes and uniforms to be referenced by index, rather than name, for efficient lookups. The index of an attribute or uniform is determined by its index into the list of attributes and uniforms passed into Shader's constructor. For example, if you provide the list of uniforms, "color", "offset", "direction", the uniform color would have index 0, offset index 1, and direction index 2. These indices can be provided to functions like getAttributeLocation(), getUniformLocation(), and the setIndexed family of functions such as setIndexedUniformMatrix4f().

See InstancedShader for the details on how to use the setIndexed family of methods to implement an instanced shader.

Shaders can either be used on their own as wrappers around GL programs and managers of their state or in conjunction with Renderer. If used with Renderer, begin() and end() will be called as needed when selected.

Constructor & Destructor Documentation

Shader::Shader	(	const AttributeSetPtr &	attributes,
		const std::vector< std::string > &	uniformNames
	)

Construct a Shader with the given list of attributes and uniforms.

Parameters

attributes	AttributeSet containing the list of indexed attributes for this shader
uniformNames	List of indexed uniforms

Member Function Documentation

virtual void Shader::begin ( )

pure virtual

Binds this shader, updating state as necessary.

Implemented in InstancedShader, and ShaderBase.

virtual void Shader::compile ( )

pure virtual

Compiles this shader, if not already compiled.

Implemented in InstancedShader, and ShaderBase.

virtual void Shader::end ( )

pure virtual

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

Implemented in InstancedShader, and ShaderBase.

virtual int Shader::getAttributeLocation ( int  index ) const

pure virtual

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

Implemented in InstancedShader, and ShaderBase.

const AttributeSetPtr& Shader::getAttributes ( ) const

inline

Returns the list of indexed Attributes for this shader, as an AttributeSet.

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

pure virtual

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

Returns

String describing compilation errors

Implemented in InstancedShader, and ShaderBase.

virtual GLuint Shader::getProgramId ( ) const

pure virtual

Returns the GL program id for this shader.

Implemented in InstancedShader, and ShaderBase.

virtual int Shader::getUniformLocation ( int  index ) const

pure virtual

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

Implemented in InstancedShader, and ShaderBase.

const std::vector<std::string>& Shader::getUniformNames ( ) const

inline

Returns the list of indexed uniforms.

virtual bool Shader::isCompiled ( ) const

pure virtual

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().

Implemented in InstancedShader, and ShaderBase.

virtual bool Shader::isCurrent ( ) const

pure virtual

Returns whether or not this shader is bound.

Implemented in InstancedShader, and ShaderBase.

virtual bool Shader::isValid ( ) const

pure virtual

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

Implemented in InstancedShader, and ShaderBase.

void Shader::setIndexedUniform1f	(	int	index,
		bool	global,
		float	value,
		float *	stateValue
	)

Set the value of a float scalar uniform at the given index.

See InstancedShader for details on the setIndexed family of methods.

Parameters

index	Index of the uniform to set
global	Whether or not this uniform is global and should be set even if the shader is not bound
value	Scalar value to set
stateValue	Memory to save off state to, or nullptr if state should not be saved

void Shader::setIndexedUniform1i	(	int	index,
		bool	global,
		int	value,
		int *	stateValue
	)

Set the value of an integer scalar uniform at the given index.

See InstancedShader for details on the setIndexed family of methods.

Parameters

index	Index of the uniform to set
global	Whether or not this uniform is global and should be set even if the shader is not bound
value	Scalar value to set
stateValue	Memory to save off state to, or nullptr if state should not be saved

void Shader::setIndexedUniform2f	(	int	index,
		bool	global,
		const Vector2 &	value,
		Vector2 *	stateValue
	)

Set the value of a 2D float vector uniform at the given index.

See InstancedShader for details on the setIndexed family of methods.

Parameters

index	Index of the uniform to set
global	Whether or not this uniform is global and should be set even if the shader is not bound
value	Vector2 to set
stateValue	Memory to save off state to, or nullptr if state should not be saved

void Shader::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.

See InstancedShader for details on the setIndexed family of methods.

Parameters

index	Index of the uniform to set
global	Whether or not this uniform is global and should be set even if the shader is not bound
value1	First vector element
value2	Second vector element
value3	Third vector element
stateValue	Memory to save off state to, or nullptr if state should not be saved

void Shader::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.

See InstancedShader for details on the setIndexed family of methods.

Parameters

index	Index of the uniform to set
global	Whether or not this uniform is global and should be set even if the shader is not bound
value1	First vector element
value2	Second vector element
value3	Third vector element
value4	Fourth vector element
stateValue	Memory to save off state to, or nullptr if state should not be saved

void Shader::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.

See InstancedShader for details on the setIndexed family of methods.

Note

This method currently differs from glUniformMatrix4fv() in that only one matrix, not an array of matrices, can be uploaded.

Parameters

index	Index of the uniform to set
global	Whether or not this uniform is global and should be set even if the shader is not bound
transpose	Whether or not to upload this matrix transposed
value	Matrix to set
stateValue	Memory to save off state to, or nullptr if state should not be saved