Wizt::GLProgram Class Reference

An OpenGL shading program. More...

#include <ocean/GLvish/GLProgram.hpp>

Inheritance diagram for Wizt::GLProgram:

Classes
struct	CannotAssignUniform
	Exception class if a uniform variable in a shader could not be assigned. More...
struct	Error
	Local error class to serve as base class for all exceptions that are thrown by GLProgram operations. More...
struct	LinkerError
	Exception that happens when there was a problem with linking compiled shader programs. More...
struct	NoSuchAttribute
	Exception thrown when a vertex attribute was not found. More...
struct	NoSuchUniform
	Exception thrown when a uniform variable was not found. More...
struct	NotSupportedCall
	Exception class if a GL call is not supported. More...
struct	UninitializedTexture
	Exception thrown if a texture is supposed to be used that has not been initialized. More...

Public Member Functions
bool	activate (const Anemone &) override
	Anemone::Tentacle Implementation: use this shader.
void	bindFragData (GLuint colorNumber, const char *name) const
bool	deactivate (const Anemone &) override
	Anemone::Tentacle Implementation: disable use of shaders.
GLint	getAttribID (const char *name) const
	Get the identifier of some attribute as defined in the Program.
GLint	getAttribID (const string &name) const
	Get the identifier of some attribute variable as defined in the Program.
GLuint	getId () const
	Get the associated OpenGL ID.
	GLProgram ()
	Constructor.
	GLProgram (const string &vertex_code, const string &fragment_code, const string &vertexsrcfilename="* Internal Vertex Shader *", const string &fragmentsrcfilename="* Internal Fragment Shader *", unsigned vertex_lineNo=0, unsigned fragment_lineNo=0)
	Construct a program with vertex and fragment shader code.
	GLProgram (const string &vertex_code, const string &vertexsrcfilename, unsigned vertex_lineNo, const string &fragment_code, const string &fragmentsrcfilename, unsigned fragment_lineNo)
std::string	InfoLog () const
	Return verbose compilation info.
bool	isValid () const
	Validates that this program is ready to use.
void	link (const RenderBasin::Program::Setup &SetupFunction=nullptr, const char *srcfilename="** OpenGL Program Shader Code **", unsigned lineNo=0)
	Link the program.
void	setAllUniforms (const Anemone &A) const override
	Setup the internally defined variables.
void	setObjectLabel (const string &Name) const
	Interfacing glObjectLabel() https://registry.khronos.org/OpenGL-Refpages/gl4/html/glObjectLabel.xhtml.
bool	setUniformValuef (const char *name, float value, bool Silent) const
	Set a variable in the program to a certain value.
bool	setUniformValuei (const char *name, GLint v0, GLint v1, bool Silent) const
void	SetupViewport () const
	Set a uniform variable int Viewport[4] in the program to contain the current OpenGL view port.
std::pair< WeakPtr< GLProgram >, string >	uniform (const char *name)
	Return some context on how to address a uniform variable in the shader.
void	use () const override
	Use the program.
	~GLProgram ()
	Destructor.
Public Member Functions inherited from Wizt::RenderBasin::Program
	Program ()
	Constructor.
bool	SourceHasChanged () const
	Check if any of the registered source files (mySources) has changed.
Public Member Functions inherited from Wizt::Anemone::Tentacle
virtual const char *	getSamplerType () const
	If this tentacle refers to some texture sampler in a shader, then hereby return the type of this sampler is it occurs in the code.
virtual int	getTextureUnit () const
	Get the texture unit number which was specified during construction, if positive then it refers to some texture unit that is used in an associated shader.
virtual size_t	memsize () const
	Return the memory occupied by this buffer if it occupies memory at all. Otherwise, returns 0 (default).
virtual size_t	NumberOfElements () const
	Returns the number of elements provided and used by this object, if it refers to countable elements.
virtual bool	updateValue (VRenderContext &Context)
	Possibly update a tentacle from settings in a context.
Public Member Functions inherited from MemCore::ReferenceBase< Tentacle >
auto	getObjectCountID () const noexcept
	Get a unique ID for this object in the given domain.
bool	isIdentical (const WeakPtr< Tentacle, Tentacle > &PossibleSelf) const noexcept
	Check if this object is identical to the one used by the given pointer.
void	mkAutoDestructive ()
	Marks this object as being automatically destructed, e.g.
refcount_t	refcount () const noexcept
	The strong reference count.
	ReferenceBase (Tentacle *that) noexcept
	Constructor, initializes reference counter to zero.
const auto &	self () const
	Return weak pointer to the object self.
refcount_t	wrefcount () const noexcept
	The weak reference count.
Public Member Functions inherited from Wizt::RenderNamespace::ProgramVariables
ProgramVariables &	merge (const ProgramVariables &, substitutes_t &substitutes, const std::string &src_original, const std::string &src_substitute)
	Merge a set of program variables into this current one and substitute the variable names by another string thereby.
void	remove (const substitutes_t &substitutes)
	Remove all variables as given in the set.
template<class T >
void	setMandatoryValue (const std::string &name, const T &t, bool isMandatory=true)
	Set a value that will raise an exception if that variable is not used in the shader program.
void	setPointValue (const std::string &name, const Eagle::FixedArray< double, 3 > &v)
	Set an vec3 uniform that is suspect to coordinate shifting.
void	setValue (const std::string &name, const Eagle::FixedArray< double, 2 > &v)
	Set an vec2 uniform.
void	setValue (const std::string &name, const Eagle::FixedArray< double, 3 > &v)
	Set an vec3 uniform.
void	setValue (const std::string &name, const Eagle::FixedArray< double, 4 > &v)
	Set an vec4 uniform.
void	setValue (const std::string &name, const Eagle::FixedArray< float, 4 > &v)
	Set an vec4 uniform of floats.
void	setValue (const std::string &name, const Eagle::FixedArray< int, 2 > &v)
	Set an vec2 uniform.
void	setValue (const std::string &name, const Eagle::FixedArray< int, 3 > &v)
	Set an vec3 uniform.
void	setValue (const std::string &name, const Eagle::Quadratic< 3, float > &M)
	Set an integer uniform.
void	setValue (const std::string &name, double d)
	Set a floating point uniform.
void	setValue (const std::string &name, int i)
	Set an integer uniform.

Static Public Member Functions
static void	dont_use_any_shaders ()
	Disable the use of any shaders.
static const char *	VarType (GLenum type)
	Tell the type of the given variable, as specified by the CannotAssignUniform exception.

Additional Inherited Members
Public Types inherited from Wizt::RenderBasin::Program
using	Setup = std::function< Parameters(const Parameters &MaximumValues)>
	The setup function when linking a program, which is given maximum values as possible by the current implementation and needs to specify the actually required values for a given shader.
using	SourceCode_t = std::map< std::string, glsl >
	Map from filename to source code.
using	Sources_t = std::map< std::string, MemCore::Filetime >
	File names and file modification/access/creation time.
Public Types inherited from MemCore::ReferenceBase< Tentacle >
using	reference_domain_t = Tentacle
	The type of the base class.
using	SelfPtr_t = WeakPtr< Tentacle, Tentacle >
	Type for a pointer to this object itself.
Public Attributes inherited from Wizt::RenderBasin::Program
Sources_t	mySources
	List of file names associated with this program and their respective modification times.
bool	SilentlyIgnoreUnknownUniforms
	Throw a RenderException if a variable is set that is not used in the program.
SourceCode_t	SourceCode
	For information only, the last complete source code that was used to compile this shader, indexed by an key word for multiple shader types.
NamedTextures_t	Textures
	A set of named textures to be used in this Program.
Public Attributes inherited from Wizt::Anemone::Tentacle
Activity_t	Activity
	A bit mask telling whether this tentacle should participate in the waving of an Anemone.
Public Attributes inherited from Wizt::RenderNamespace::ProgramVariables
FloatValues_t	FloatValues
	A set of floating point values that will be set for this program.
IntValues_t	IntValues
	A set of integer values that will be set for this program.
std::map< std::string, Eagle::FixedArray< int, 2 > >	iVec2Values
	A set of 3D integer vectors that will be set for this program as uniforms.
std::map< std::string, Eagle::FixedArray< int, 3 > >	iVec3Values
	A set of 3D integer vectors that will be set for this program as uniforms.
std::map< std::string, std::vector< Eagle::Quadratic< 3, float > > >	M33ArrayValues
	A set of matric values that will be set for this program.
std::map< std::string, Eagle::Quadratic< 3, float > >	M33Values
	A set of matric values that will be set for this program.
std::map< std::string, Eagle::FixedArray< double, 3 > >	Point3Values
	A set of 3D vectors that will be set for this program as uniforms.
std::map< std::string, Eagle::FixedArray< double, 2 > >	Vec2Values
	A set of 2D vectors that will be set for this program as uniforms.
std::map< std::string, Eagle::FixedArray< double, 3 > >	Vec3Values
	A set of 3D vectors that will be set for this program as uniforms.
std::map< std::string, Eagle::FixedArray< double, 4 > >	Vec4Values
	A set of 4D vectors that will be set for this program as uniforms.
Protected Member Functions inherited from Wizt::RenderBasin::Program
virtual	~Program ()=0
	Destructor.
Protected Member Functions inherited from MemCore::ReferenceBase< Tentacle >
virtual void	extremeUnction ()
	A virtual function that will be called just before the object is destroyed.
ReferenceBase &	operator= (const ReferenceBase &R)
	Protected assignment operator (should not be called).
void	suicide ()
	Delete this.
virtual	~ReferenceBase ()
	Virtual destructor.

Detailed Description

An OpenGL shading program.

A most simple way to enable a shader is like this:

Ref<GLProgram> myProgram(
"void main(void)\n"
"{\n"
"       gl_Position = ftransform();\n"
"}"
,
"void main (void)\n"
"{\n"
"       gl_FragColor = vec4(0,1,0,.5);\n"
"}\n"
                                );
 
                        myProgram->use();

The value of a floating point slot may be directly assigned to a uniform shader variable:

scaleFactor << Context > MyProgram;

An additional function may be applied during assignment:

scaleFactor << Context > (MyProgram + pow10);

Constructor & Destructor Documentation

GLProgram() [1/2]

Wizt::GLProgram::GLProgram	(	const string &	vertex_code,
		const string &	fragment_code,
		const string &	vertexsrcfilename = "* Internal Vertex Shader *",
		const string &	fragmentsrcfilename = "* Internal Fragment Shader *",
		unsigned	vertex_lineNo = 0,
		unsigned	fragment_lineNo = 0
	)

Construct a program with vertex and fragment shader code.

The specified vertex and fragment shader codes are compiled and linked immediatly.

The most trivial vertex shade is this:

void main(void)
{
        gl_Position = ftransform();
}

The most trivial fragment shader is this:

void main (void)
{
        gl_FragColor = gl_Color;
}

References GLProgram(), link(), and setObjectLabel().

GLProgram() [2/2]

Wizt::GLProgram::GLProgram ( const string &  vertex_code, const string &  vertexsrcfilename, unsigned  vertex_lineNo, const string &  fragment_code, const string &  fragmentsrcfilename, unsigned  fragment_lineNo  )

inline

       Constructor with alternative order of arguments such that the
       GLSL_SHADER and GLSL_SOURCE macros can be used.
       Define the GLSL source like this:
       @code

GLSL_SHADER( fragment_shader ) = R"SHADER( #version 450 out vec4 fragmentColor; void main(void) { fragmentColor = vec4(1,0,0,0); } )SHADER" ; and construct the GLProgram like this:

RefPtr<GLProgram> myProgram = new GLProgram( vertex_shader, "vertex_shader", VS_LINE,
                                             GLSL_SOURCE( fragment_shader ) );

Member Function Documentation

bindFragData()

void Wizt::GLProgram::bindFragData	(	GLuint	colorNumber,
		const char *	name
	)		const

Note

Calls the following OpenGL routine: http://www.opengl.org/sdk/docs/man4/xhtml/glBindFragDataLocation.xml Should be called before link(), and after program creation.

getAttribID() [1/2]

GLint Wizt::GLProgram::getAttribID

(

const char *

name

)

const

Get the identifier of some attribute as defined in the Program.

Attributes are values that are provided per vertex and declared in the Program using GSGL like in this following code fragment:

attribute float value;

References isValid().

getAttribID() [2/2]

GLint Wizt::GLProgram::getAttribID ( const string &  name ) const

inline

Get the identifier of some attribute variable as defined in the Program.

Attributes are values that are provided per vertex and declared in the Program using GSGL like in this following code fragment:

attribute float value;

isValid()

bool Wizt::GLProgram::isValid

(

)

const

Validates that this program is ready to use.

http://www.opengl.org/sdk/docs/man/xhtml/glValidateProgram.xml

Referenced by getAttribID().

setUniformValuef()

bool Wizt::GLProgram::setUniformValuef	(	const char *	name,
		float	value,
		bool	Silent
	)		const

Set a variable in the program to a certain value.

Parameters

name	The variable as given in the program.

Returns

false, if the certain name is not valid in the program.

Referenced by setAllUniforms().

setUniformValuei()

bool Wizt::GLProgram::setUniformValuei	(	const char *	name,
		GLint	v0,
		GLint	v1,
		bool	Silent
	)		const

Note

Calls the following OpenGL routines: http://www.opengl.org/sdk/docs/man/xhtml/glGetUniformLocation.xml http://www.opengl.org/sdk/docs/man/xhtml/glUniform.xml

uniform()

std::pair< WeakPtr< GLProgram >, string > Wizt::GLProgram::uniform

(

const char *

name

)

Return some context on how to address a uniform variable in the shader.

Used for the >> operator.

References MemCore::ReferenceBase< Tentacle >::self().