Provide the access to the OpenGL shaders. More...

#include <shader.h>

Public Member Functions
	SHADER ()

virtual	~SHADER ()

template<typename... Args>
bool	LoadShaderFromStrings (SHADER_TYPE aShaderType, Args &&... aArgs)
	Add a shader and compile the shader sources. More...

bool	LoadShaderFromFile (SHADER_TYPE aShaderType, const std::string &aShaderSourceName)
	Load one of the built-in shaders and compiles it. More...

bool	Link ()
	Link the shaders. More...

bool	IsLinked () const
	Return true if shaders are linked correctly. More...

void	Use ()
	Use the shader. More...

void	Deactivate ()
	Deactivate the shader and use the default OpenGL program. More...

bool	IsActive () const
	Return the current state of the shader. More...

void	ConfigureGeometryShader (GLuint maxVertices, GLuint geometryInputType, GLuint geometryOutputType)
	Configure the geometry shader - has to be done before linking! More...

int	AddParameter (const std::string &aParameterName)
	Add a parameter to the parameter queue. More...

void	SetParameter (int aParameterNumber, float aValue) const
	Set a parameter of the shader. More...

void	SetParameter (int aParameterNumber, int aValue) const

void	SetParameter (int aParameterNumber, const VECTOR2D &aValue) const

void	SetParameter (int aParameterNumber, float f0, float f1, float f2, float f3) const

int	GetAttribute (const std::string &aAttributeName) const
	Get an attribute location. More...

Static Public Member Functions
static std::string	ReadSource (const std::string &aShaderSourceName)
	Read the shader source file. More...

Private Member Functions
bool	loadShaderFromStringArray (SHADER_TYPE aShaderType, const char **aArray, size_t aSize)
	Compile vertex of fragment shader source code into the program. More...

void	programInfo (GLuint aProgram)
	Get the shader program information. More...

void	shaderInfo (GLuint aShader)
	Get the shader information. More...

Private Attributes
std::deque< GLuint >	shaderNumbers
	Shader number list. More...

GLuint	programNumber
	Shader program number. More...

bool	isProgramCreated
	Flag for program creation. More...

bool	isShaderLinked
	Is the shader linked? More...

bool	active
	Is any of shaders used? More...

GLuint	maximumVertices
	The maximum of vertices to be generated. More...

GLuint	geomInputType
	Output type [e.g. GL_LINES, GL_TRIANGLES, GL_QUADS etc.]. More...

GLuint	geomOutputType

std::deque< GLint >	parameterLocation
	Location of the parameter. More...

Detailed Description

Provide the access to the OpenGL shaders.

The purpose of this class is advanced drawing with OpenGL. One example is using the pixel shader for drawing exact circles or for anti-aliasing. This class supports vertex, geometry and fragment shaders.

Make sure that the hardware supports these features. This can be identified with the "GLEW" library.

Definition at line 76 of file shader.h.

Constructor & Destructor Documentation

◆ SHADER()

SHADER::SHADER ( )

Definition at line 41 of file shader.cpp.

 :
 isProgramCreated( false ),
 isShaderLinked( false ),
 active( false ),
 maximumVertices( 4 ),
 geomInputType( GL_LINES ),
 geomOutputType( GL_LINES )
 
{
 // Do not have uninitialized members:
 programNumber = 0;
}

References programNumber.

◆ ~SHADER()

SHADER::~SHADER ( )

virtual

Definition at line 55 of file shader.cpp.

{
 if( active )
 Deactivate();
 
 if( isProgramCreated )
 {
 if( glIsShader )
 {
 // Delete the shaders and the program
 for( std::deque<GLuint>::iterator it = shaderNumbers.begin(); it != shaderNumbers.end();
 ++it )
 {
 GLuint shader = *it;
 
 if( glIsShader( shader ) )
 {
 glDetachShader( programNumber, shader );
 glDeleteShader( shader );
 }
 }
 
 glDeleteProgram( programNumber );
 }
 }
}

References active, Deactivate(), isProgramCreated, programNumber, and shaderNumbers.

Member Function Documentation

◆ AddParameter()

int SHADER::AddParameter ( const std::string & aParameterName )

Add a parameter to the parameter queue.

To communicate with the shader use this function to set up the names for the uniform variables. These are queued in a list and can be assigned with the SetParameter(..) method using the queue position.

Parameters

aParameterName is the name of the parameter.

Returns: the added parameter location.

Definition at line 130 of file shader.cpp.

{
 GLint location = glGetUniformLocation( programNumber, aParameterName.c_str() );
 
 if( location >= 0 )
 parameterLocation.push_back( location );
 else
 throw std::runtime_error( "Could not find shader uniform: " + aParameterName );
 
 return parameterLocation.size() - 1;
}

References parameterLocation, and programNumber.

Referenced by KIGFX::OPENGL_GAL::BeginDrawing().

◆ ConfigureGeometryShader()

void SHADER::ConfigureGeometryShader	(	GLuint	maxVertices,
		GLuint	geometryInputType,
		GLuint	geometryOutputType
	)

Configure the geometry shader - has to be done before linking!

Parameters

maxVertices	is the maximum of vertices to be generated.
geometryInputType	is the input type [e.g. GL_LINES, GL_TRIANGLES, GL_QUADS etc.]
geometryOutputType	is the output type [e.g. GL_LINES, GL_TRIANGLES, GL_QUADS etc.]

Definition at line 92 of file shader.cpp.

{
 maximumVertices = maxVertices;
 geomInputType = geometryInputType;
 geomOutputType = geometryOutputType;
}

References geomInputType, geomOutputType, and maximumVertices.

◆ Deactivate()

void KIGFX::SHADER::Deactivate ( )

inline

Deactivate the shader and use the default OpenGL program.

Definition at line 135 of file shader.h.

 {
 glUseProgram( 0 );
 active = false;
 }

References active.

Referenced by KIGFX::OPENGL_GAL::BeginDrawing(), KIGFX::GPU_CACHED_MANAGER::EndDrawing(), KIGFX::GPU_NONCACHED_MANAGER::EndDrawing(), and ~SHADER().

◆ GetAttribute()

int SHADER::GetAttribute ( const std::string & aAttributeName ) const

Get an attribute location.

Parameters

aAttributeName is the name of the attribute.

Returns: the location.

Definition at line 172 of file shader.cpp.

{
 return glGetAttribLocation( programNumber, aAttributeName.c_str() );
}

References programNumber.

Referenced by KIGFX::GPU_MANAGER::SetShader().

◆ IsActive()

bool KIGFX::SHADER::IsActive ( ) const

inline

Return the current state of the shader.

Returns: True if any of shaders is enabled.

Definition at line 146 of file shader.h.

 {
 return active;
 }

References active.

◆ IsLinked()

bool KIGFX::SHADER::IsLinked ( ) const

inline

Return true if shaders are linked correctly.

Definition at line 118 of file shader.h.

 {
 return isShaderLinked;
 }

References isShaderLinked.

Referenced by KIGFX::OPENGL_GAL::init().

◆ Link()

bool SHADER::Link ( )

Link the shaders.

Returns: true in case of success, false otherwise.

Definition at line 101 of file shader.cpp.

{
 // Shader linking
 glLinkProgram( programNumber );
 programInfo( programNumber );
 
 // Check the Link state
 GLint tmp;
 glGetProgramiv( programNumber, GL_LINK_STATUS, &tmp );
 isShaderLinked = !!tmp;
 
#ifdef DEBUG
 if( !isShaderLinked )
 {
 int maxLength;
 glGetProgramiv( programNumber, GL_INFO_LOG_LENGTH, &maxLength );
 maxLength = maxLength + 1;
 char* linkInfoLog = new char[maxLength];
 glGetProgramInfoLog( programNumber, maxLength, &maxLength, linkInfoLog );
 std::cerr << "Shader linking error:" << std::endl;
 std::cerr << linkInfoLog;
 delete[] linkInfoLog;
 }
#endif /* DEBUG */
 
 return isShaderLinked;
}

References isShaderLinked, programInfo(), and programNumber.

Referenced by KIGFX::OPENGL_GAL::init().

◆ LoadShaderFromFile()

bool SHADER::LoadShaderFromFile	(	SHADER_TYPE	aShaderType,
		const std::string &	aShaderSourceName
	)

Load one of the built-in shaders and compiles it.

Parameters

aShaderSourceName	is the shader source file name.
aShaderType	is the type of the shader.

Returns: True in case of success, false otherwise.

Definition at line 83 of file shader.cpp.

{
 // Load shader sources
 const std::string shaderSource = ReadSource( aShaderSourceName );
 
 return LoadShaderFromStrings( aShaderType, shaderSource );
}

References LoadShaderFromStrings(), and ReadSource().

◆ loadShaderFromStringArray()

bool SHADER::loadShaderFromStringArray	(	SHADER_TYPE	aShaderType,
		const char **	aArray,
		size_t	aSize
	)

private

Compile vertex of fragment shader source code into the program.

Definition at line 238 of file shader.cpp.

{
 assert( !isShaderLinked );
 
 // Create the program
 if( !isProgramCreated )
 {
 programNumber = glCreateProgram();
 isProgramCreated = true;
 }
 
 // Create a shader
 GLuint shaderNumber = glCreateShader( aShaderType );
 shaderNumbers.push_back( shaderNumber );
 
 // Get the program info
 programInfo( programNumber );
 
 // Attach the sources
 glShaderSource( shaderNumber, aSize, (const GLchar**) aArray, nullptr );
 programInfo( programNumber );
 
 // Compile and attach shader to the program
 glCompileShader( shaderNumber );
 GLint status;
 glGetShaderiv( shaderNumber, GL_COMPILE_STATUS, &status );
 
 if( status != GL_TRUE )
 {
 shaderInfo( shaderNumber );
 
 GLint maxLength = 0;
 glGetShaderiv( shaderNumber, GL_INFO_LOG_LENGTH, &maxLength );
 
 // The maxLength includes the NULL character
 std::vector<GLchar> errorLog( (size_t) maxLength );
 glGetShaderInfoLog( shaderNumber, maxLength, &maxLength, &errorLog[0] );
 
 // Provide the infolog in whatever manor you deem best.
 // Exit with failure.
 glDeleteShader( shaderNumber ); // Don't leak the shader.
 
 throw std::runtime_error( &errorLog[0] );
 }
 
 glAttachShader( programNumber, shaderNumber );
 programInfo( programNumber );
 
 // Special handling for the geometry shader
 if( aShaderType == SHADER_TYPE_GEOMETRY )
 {
 glProgramParameteriEXT( programNumber, GL_GEOMETRY_VERTICES_OUT_EXT, maximumVertices );
 glProgramParameteriEXT( programNumber, GL_GEOMETRY_INPUT_TYPE_EXT, geomInputType );
 glProgramParameteriEXT( programNumber, GL_GEOMETRY_OUTPUT_TYPE_EXT, geomOutputType );
 }
 
 return true;
}

References geomInputType, geomOutputType, isProgramCreated, isShaderLinked, maximumVertices, programInfo(), programNumber, KIGFX::SHADER_TYPE_GEOMETRY, shaderInfo(), and shaderNumbers.

Referenced by LoadShaderFromStrings().

◆ LoadShaderFromStrings()

template<typename... Args>

bool KIGFX::SHADER::LoadShaderFromStrings	(	SHADER_TYPE	aShaderType,
		Args &&...	aArgs
	)

inline

Add a shader and compile the shader sources.

Parameters

aArgs	is the list of strings (std::string or convertible to const char*) which are concatenated and compiled as a single shader source code.
aShaderType	is the type of the shader.

Returns: True in case of success, false otherwise.

Definition at line 93 of file shader.h.

 {
 const char* arr[] = { DETAIL::translateStringArg( aArgs )... };
 return loadShaderFromStringArray( aShaderType, arr, sizeof...(Args) );
 }

References loadShaderFromStringArray(), and KIGFX::DETAIL::translateStringArg().

Referenced by KIGFX::OPENGL_GAL::init(), and LoadShaderFromFile().

◆ programInfo()

void SHADER::programInfo ( GLuint aProgram )

private

Get the shader program information.

Parameters

aProgram is the program number.

Definition at line 178 of file shader.cpp.

{
 GLint glInfoLogLength = 0;
 GLint writtenChars = 0;
 
 // Get the length of the info string
 glGetProgramiv( aProgram, GL_INFO_LOG_LENGTH, &glInfoLogLength );
 
 // Print the information
 if( glInfoLogLength > 2 )
 {
 GLchar* glInfoLog = new GLchar[glInfoLogLength];
 glGetProgramInfoLog( aProgram, glInfoLogLength, &writtenChars, glInfoLog );
 
 delete[] glInfoLog;
 }
}

References aProgram.

Referenced by Link(), and loadShaderFromStringArray().

◆ ReadSource()

std::string SHADER::ReadSource ( const std::string & aShaderSourceName )

static

Read the shader source file.

Parameters

aShaderSourceName is the shader source file name.

Returns: the source as string

Definition at line 216 of file shader.cpp.

{
 // Open the shader source for reading
 std::ifstream inputFile( aShaderSourceName.c_str(), std::ifstream::in );
 std::string shaderSource;
 
 if( !inputFile )
 throw std::runtime_error( "Can't read the shader source: " + aShaderSourceName );
 
 std::string shaderSourceLine;
 
 // Read all lines from the text file
 while( getline( inputFile, shaderSourceLine ) )
 {
 shaderSource += shaderSourceLine;
 shaderSource += "\n";
 }
 
 return shaderSource;
}

Referenced by LoadShaderFromFile().

◆ SetParameter() [1/4]

void SHADER::SetParameter	(	int	aParameterNumber,
		const VECTOR2D &	aValue
	)		const

Definition at line 165 of file shader.cpp.

{
 assert( (unsigned) aParameterNumber < parameterLocation.size() );
 glUniform2f( parameterLocation[aParameterNumber], static_cast<GLfloat>( aValue.x ), static_cast<GLfloat>( aValue.y ) );
}

References parameterLocation, VECTOR2< T >::x, and VECTOR2< T >::y.

◆ SetParameter() [2/4]

void SHADER::SetParameter	(	int	aParameterNumber,
		float	aValue
	)		const

Set a parameter of the shader.

Parameters

aParameterNumber	is the number of the parameter.
aValue	is the value of the parameter.

Definition at line 143 of file shader.cpp.

{
 assert( (unsigned) parameterNumber < parameterLocation.size() );
 
 glUniform1f( parameterLocation[parameterNumber], value );
}

References parameterLocation.

Referenced by KIGFX::OPENGL_GAL::BeginDrawing().

◆ SetParameter() [3/4]

void SHADER::SetParameter	(	int	aParameterNumber,
		float	f0,
		float	f1,
		float	f2,
		float	f3
	)		const

Definition at line 158 of file shader.cpp.

{
 assert( (unsigned) parameterNumber < parameterLocation.size() );
 float arr[4] = { f0, f1, f2, f3 };
 glUniform4fv( parameterLocation[parameterNumber], 1, arr );
}

References parameterLocation.

◆ SetParameter() [4/4]

void SHADER::SetParameter	(	int	aParameterNumber,
		int	aValue
	)		const

Definition at line 151 of file shader.cpp.

{
 assert( (unsigned) parameterNumber < parameterLocation.size() );
 
 glUniform1i( parameterLocation[parameterNumber], value );
}

References parameterLocation.

◆ shaderInfo()

void SHADER::shaderInfo ( GLuint aShader )

private

Get the shader information.

Parameters

aShader is the shader number.

Definition at line 197 of file shader.cpp.

{
 GLint glInfoLogLength = 0;
 GLint writtenChars = 0;
 
 // Get the length of the info string
 glGetShaderiv( aShader, GL_INFO_LOG_LENGTH, &glInfoLogLength );
 
 // Print the information
 if( glInfoLogLength > 2 )
 {
 GLchar* glInfoLog = new GLchar[glInfoLogLength];
 glGetShaderInfoLog( aShader, glInfoLogLength, &writtenChars, glInfoLog );
 
 delete[] glInfoLog;
 }
}

Referenced by loadShaderFromStringArray().

◆ Use()

void KIGFX::SHADER::Use ( )

inline

Use the shader.

Definition at line 126 of file shader.h.

 {
 glUseProgram( programNumber );
 active = true;
 }

References active, and programNumber.

Referenced by KIGFX::OPENGL_GAL::BeginDrawing(), KIGFX::GPU_CACHED_MANAGER::EndDrawing(), and KIGFX::GPU_NONCACHED_MANAGER::EndDrawing().

Member Data Documentation

◆ active

bool KIGFX::SHADER::active

private

Is any of shaders used?

Definition at line 224 of file shader.h.

Referenced by Deactivate(), IsActive(), Use(), and ~SHADER().

◆ geomInputType

GLuint KIGFX::SHADER::geomInputType

private

Output type [e.g. GL_LINES, GL_TRIANGLES, GL_QUADS etc.].

Definition at line 228 of file shader.h.

Referenced by ConfigureGeometryShader(), and loadShaderFromStringArray().

◆ geomOutputType

GLuint KIGFX::SHADER::geomOutputType

private

Definition at line 231 of file shader.h.

Referenced by ConfigureGeometryShader(), and loadShaderFromStringArray().

◆ isProgramCreated

bool KIGFX::SHADER::isProgramCreated

private

Flag for program creation.

Definition at line 222 of file shader.h.

Referenced by loadShaderFromStringArray(), and ~SHADER().

◆ isShaderLinked

bool KIGFX::SHADER::isShaderLinked

private

Is the shader linked?

Definition at line 223 of file shader.h.

Referenced by IsLinked(), Link(), and loadShaderFromStringArray().

◆ maximumVertices

GLuint KIGFX::SHADER::maximumVertices

private

The maximum of vertices to be generated.

Input type [e.g. GL_LINES, GL_TRIANGLES, GL_QUADS etc.]

Definition at line 225 of file shader.h.

Referenced by ConfigureGeometryShader(), and loadShaderFromStringArray().

◆ parameterLocation

std::deque<GLint> KIGFX::SHADER::parameterLocation

private

Location of the parameter.

Definition at line 232 of file shader.h.

Referenced by AddParameter(), and SetParameter().

◆ programNumber

GLuint KIGFX::SHADER::programNumber

private

Shader program number.

Definition at line 221 of file shader.h.

Referenced by AddParameter(), GetAttribute(), Link(), loadShaderFromStringArray(), SHADER(), Use(), and ~SHADER().

◆ shaderNumbers

std::deque<GLuint> KIGFX::SHADER::shaderNumbers

private

Shader number list.

Definition at line 220 of file shader.h.

Referenced by loadShaderFromStringArray(), and ~SHADER().

The documentation for this class was generated from the following files:

Public Member Functions

Static Public Member Functions

Private Member Functions

Private Attributes

Detailed Description

Constructor & Destructor Documentation

◆ SHADER()

◆ ~SHADER()

Member Function Documentation

◆ AddParameter()

◆ ConfigureGeometryShader()

◆ Deactivate()

◆ GetAttribute()

◆ IsActive()

◆ IsLinked()

◆ Link()

◆ LoadShaderFromFile()

◆ loadShaderFromStringArray()

◆ LoadShaderFromStrings()

◆ programInfo()

◆ ReadSource()

◆ SetParameter() [1/4]

◆ SetParameter() [2/4]

◆ SetParameter() [3/4]

◆ SetParameter() [4/4]

◆ shaderInfo()

◆ Use()

Member Data Documentation

◆ active

◆ geomInputType

◆ geomOutputType

◆ isProgramCreated

◆ isShaderLinked

◆ maximumVertices

◆ parameterLocation

◆ programNumber

◆ shaderNumbers