Geogram  Version 1.9.1
A programming library of geometric algorithms
GLSL.h File Reference

Utilities for manipulating GLSL shaders. More...

Go to the source code of this file.

Classes

struct  GEO::GLSL::GLSLCompileError
 Exception thrown when a GLSL shader fails to compiled. More...
 
class  GEO::GLSL::Source
 A GLSL source. More...
 
class  GEO::GLSL::PseudoFileProvider
 A class that can register functions to the GLSL pseudo file system. More...
 

Namespaces

 GEO
 Global Vorpaline namespace.
 

Typedefs

typedef void(* GEO::GLSL::PseudoFile) (PseudoFileProvider *provider, std::vector< Source > &sources)
 A pointer to a function registered as a pseudo file in the GLSL pseudo file system. More...
 

Functions

void GEOGRAM_GFX_API GEO::GLSL::initialize ()
 Initializes some GLSL functions and objects. More...
 
void GEOGRAM_GFX_API GEO::GLSL::terminate ()
 Terminates GLSL functions and objects. More...
 
double GEOGRAM_GFX_API GEO::GLSL::supported_language_version ()
 Gets the supported GLSL language version. More...
 
void GEOGRAM_GFX_API GEO::GLSL::register_GLSL_include_file (const std::string &name, const char *source)
 Registers a file in the GLSL pseudo file system. More...
 
void GEOGRAM_GFX_API GEO::GLSL::register_GLSL_include_file (const std::string &name, PseudoFile file)
 Registers a pseudo file in the GLSL pseudo file system. More...
 
const char * GEO::GLSL::get_GLSL_include_file (const std::string &name)
 Gets a GLSL include file by file name. More...
 
GLuint GEOGRAM_GFX_API GEO::GLSL::compile_shader_with_includes (GLenum target, const char *source, PseudoFileProvider *provider)
 Compiles a shader for a specific target. More...
 
GLuint GEOGRAM_GFX_API GEO::GLSL::compile_program_with_includes_no_link (PseudoFileProvider *provider, const char *shader1, const char *shader2=nullptr, const char *shader3=nullptr, const char *shader4=nullptr, const char *shader5=nullptr, const char *shader6=nullptr)
 Compiles a program from shader sources. More...
 
GLuint GEOGRAM_GFX_API GEO::GLSL::compile_shader (GLenum target, const char **sources, index_t nb_sources)
 Compiles a shader for a specific target. More...
 
GLuint GEOGRAM_GFX_API GEO::GLSL::compile_shader (GLenum target, const char *source1, const char *source2, const char *source3=nullptr, const char *source4=nullptr, const char *source5=nullptr, const char *source6=nullptr, const char *source7=nullptr, const char *source8=nullptr, const char *source9=nullptr, const char *source10=nullptr, const char *source11=nullptr, const char *source12=nullptr, const char *source13=nullptr, const char *source14=nullptr, const char *source15=nullptr, const char *source16=nullptr, const char *source17=nullptr, const char *source18=nullptr, const char *source19=nullptr, const char *source20=nullptr)
 Compiles a shader for a specific target. More...
 
void GEOGRAM_GFX_API GEO::GLSL::link_program (GLuint program)
 Links a program. More...
 
GLuint GEOGRAM_GFX_API GEO::GLSL::create_program_from_shaders_no_link (GLuint shader,...)
 Creates a GLSL program from a zero-terminated list of shaders. More...
 
GLuint GEOGRAM_GFX_API GEO::GLSL::create_program_from_shaders (GLuint shader,...)
 Creates a GLSL program from a zero-terminated list of shaders. More...
 
GLuint GEOGRAM_GFX_API GEO::GLSL::create_program_from_string_no_link (const char *string, bool copy_string=true)
 Creates a GLSL program from a string. More...
 
GLuint GEOGRAM_GFX_API GEO::GLSL::create_program_from_file_no_link (const std::string &filename)
 Creates a GLSL program from a file. More...
 
template<class T >
bool GEO::GLSL::set_program_uniform_by_name (GLuint shader_id, const char *name, T val)
 Sets a uniform variable in a shader by name. More...
 
template<>
bool GEO::GLSL::set_program_uniform_by_name (GLuint shader_id, const char *name, bool val)
 
template<>
bool GEO::GLSL::set_program_uniform_by_name (GLuint shader_id, const char *name, float val)
 
template<>
bool GEO::GLSL::set_program_uniform_by_name (GLuint shader_id, const char *name, double val)
 
template<>
bool GEO::GLSL::set_program_uniform_by_name (GLuint shader_id, const char *name, int val)
 
template<>
bool GEO::GLSL::set_program_uniform_by_name (GLuint shader_id, const char *name, unsigned int val)
 
bool GEO::GLSL::set_program_uniform_by_name (GLuint shader_id, const char *name, index_t count, float *values)
 Sets an array of uniform variables in a shader by name. More...
 
bool GEO::GLSL::set_program_uniform_by_name (GLuint shader_id, const char *name, float x, float y)
 
GLint GEOGRAM_GFX_API GEO::GLSL::get_uniform_variable_offset (GLuint program, const char *varname)
 Gets the offset of a uniform variable relative to the uniform block it is declared in. More...
 
size_t GEOGRAM_GFX_API GEO::GLSL::get_uniform_variable_array_stride (GLuint program, const char *varname)
 Queries array stride for a variable in a GLSL program using introspection. More...
 
void GEOGRAM_GFX_API GEO::GLSL::introspect_program (GLuint program)
 Outputs to the logger everything that can be queried about a program using OpenGL introspection APIs.
 

Detailed Description

Utilities for manipulating GLSL shaders.

Definition in file GLSL.h.

Typedef Documentation

◆ PseudoFile

typedef void(* GEO::GLSL::PseudoFile) (PseudoFileProvider *provider, std::vector< Source > &sources)

A pointer to a function registered as a pseudo file in the GLSL pseudo file system.

The GLSL pseudo file system manages the include directives. A PseudoFile is a pointer to a function that fills-in the file contents. The file contents is a vector of Source objects, that can be either constant string litterals or dynamically created strings.

Definition at line 192 of file GLSL.h.

Function Documentation

◆ compile_program_with_includes_no_link()

GLuint GEOGRAM_GFX_API GEO::GLSL::compile_program_with_includes_no_link ( PseudoFileProvider provider,
const char *  shader1,
const char *  shader2 = nullptr,
const char *  shader3 = nullptr,
const char *  shader4 = nullptr,
const char *  shader5 = nullptr,
const char *  shader6 = nullptr 
)

Compiles a program from shader sources.

Parameters
[in]providera pointer to an object that implements the PseudoFileProvider interface (typically a GLUP Context)
[in]shader1,shader2,shader3,shader4,shader5,shader6up to six shader sources definition. Each shader source definition should begin with //stage STAGE where STAGE is one of GL_VERTEX_SHADER, GL_FRAGMENT_SHADER, GL_GEOMETRY_SHADER, GL_TESSELLATION_SHADER, GL_TESS_EVALUATION_SHADER
Returns
the OpenGL opaque Id of the created program object
Exceptions
GLSLCompileError

◆ compile_shader() [1/2]

GLuint GEOGRAM_GFX_API GEO::GLSL::compile_shader ( GLenum  target,
const char **  sources,
index_t  nb_sources 
)

Compiles a shader for a specific target.

One can split the source of the shader into different strings, one of them being used for library functions common to different shaders. It may seem more natural to generate a shader object with library functions, but OpenGL documentation does not recommend to do so (and it did not seem to work). Errors are detected and displayed to std::err.

Parameters
[in]targetthe OpenGL shader target (one of GL_COMPUTE_SHADER, GL_VERTEX_SHADER, GL_TESS_CONTROL_SHADER, GL_TESS_EVALUATION_SHADER, GL_GEOMETRY_SHADER, GL_FRAGMENT_SHADER)
[in]sourcesan array of pointer to ASCII strings that contain the source of the shader
[in]nb_sourcesnumber of strings in sources
Returns
the OpenGL opaque Id of the created shader object
Exceptions
GLSLCompileError

◆ compile_shader() [2/2]

GLuint GEOGRAM_GFX_API GEO::GLSL::compile_shader ( GLenum  target,
const char *  source1,
const char *  source2,
const char *  source3 = nullptr,
const char *  source4 = nullptr,
const char *  source5 = nullptr,
const char *  source6 = nullptr,
const char *  source7 = nullptr,
const char *  source8 = nullptr,
const char *  source9 = nullptr,
const char *  source10 = nullptr,
const char *  source11 = nullptr,
const char *  source12 = nullptr,
const char *  source13 = nullptr,
const char *  source14 = nullptr,
const char *  source15 = nullptr,
const char *  source16 = nullptr,
const char *  source17 = nullptr,
const char *  source18 = nullptr,
const char *  source19 = nullptr,
const char *  source20 = nullptr 
)

Compiles a shader for a specific target.

One can split the source of the shader into different strings, one of them being used for library functions common to different shaders. It may seem more natural to generate a shader object with library functions, but OpenGL documentation does not recommend to do so (and it did not seem to work). Errors are detected and displayed to std::err.

Parameters
[in]targetthe OpenGL shader target (one of GL_COMPUTE_SHADER, GL_VERTEX_SHADER, GL_TESS_CONTROL_SHADER, GL_TESS_EVALUATION_SHADER, GL_GEOMETRY_SHADER, GL_FRAGMENT_SHADER)
[in]source1,source2,...ASCII strings that will be concatened to form the source of the shader. It needs to be terminated by 0.
Returns
the OpenGL opaque Id of the created shader object
Exceptions
GLSLCompileError
Note
Could have been implemented using varargs, but I had problems with it (crashes that I could not fix), and it is not recommended anyway (does not have typechecking).

◆ compile_shader_with_includes()

GLuint GEOGRAM_GFX_API GEO::GLSL::compile_shader_with_includes ( GLenum  target,
const char *  source,
PseudoFileProvider provider 
)

Compiles a shader for a specific target.

This version of compile_shader() supports the include directive through the GLSL pseudo file system. Errors are detected and displayed to std::err.

Parameters
[in]targetthe OpenGL shader target (one of GL_COMPUTE_SHADER, GL_VERTEX_SHADER, GL_TESS_CONTROL_SHADER, GL_TESS_EVALUATION_SHADER, GL_GEOMETRY_SHADER, GL_FRAGMENT_SHADER)
[in]sourcean ASCII string that contain the source of the shader
[in]providera pointer to an object that implements the PseudoFileProvider interface (typically a GLUP Context)
Returns
the OpenGL opaque Id of the created shader object
Exceptions
GLSLCompileError

◆ create_program_from_file_no_link()

GLuint GEOGRAM_GFX_API GEO::GLSL::create_program_from_file_no_link ( const std::string &  filename)

Creates a GLSL program from a file.

The file contains a list of shaders, delimited by begin-end statements (see setup_program_from_string()).

Note
link_program() needs to be called after.
Parameters
[in]filenamethe name of the file
Exceptions
GLSLCompileError

◆ create_program_from_shaders()

GLuint GEOGRAM_GFX_API GEO::GLSL::create_program_from_shaders ( GLuint  shader,
  ... 
)

Creates a GLSL program from a zero-terminated list of shaders.

Errors are detected and displayed to the Logger.

Note
If the program has vertex attributes and needs glBindAttribLocation(), then use create_program_from_shaders_no_link() instead.
Parameters
[in]shaderthe first shader of the list
Returns
the OpenGL opaque Id of the created program

◆ create_program_from_shaders_no_link()

GLuint GEOGRAM_GFX_API GEO::GLSL::create_program_from_shaders_no_link ( GLuint  shader,
  ... 
)

Creates a GLSL program from a zero-terminated list of shaders.

Errors are detected and displayed to the Logger.

Note
link_program() needs to be called after. If the program has vertex attributes, then glBindAttribLocation() needs to be called after create_program_from_shaders_no_link() and before link_program().
Parameters
[in]shaderthe first shader of the list
Returns
the OpenGL opaque Id of the created program

◆ create_program_from_string_no_link()

GLuint GEOGRAM_GFX_API GEO::GLSL::create_program_from_string_no_link ( const char *  string,
bool  copy_string = true 
)

Creates a GLSL program from a string.

The string may contain several shaders. Each shader is delimited by begin-end statements: #begin(SHADER_TYPE) / #end(SHADER_TYPE) where SHADER_TYPE is one of GL_VERTEX_SHADER, GL_FRAGMENT_SHADER, GL_GEOMETRY_SHADER, GL_TESS_CONTROL_SHADER, GL_TESS_EVALUATION_SHADER.

Note
link_program() needs to be called after.
Parameters
[in,out]stringthe combined shaders that constitute the program.
[in]copy_stringif true, the input string is copied internally. The function temporarily modifies the input string (and then restores it on exit). This may be forbidden when input string is a constant char array (string litteral in source code). In this case, the input string is copied to a temporary buffer.
Returns
the OpenGL opaque Id of the created shader object
Exceptions
GLSLCompileError

◆ get_GLSL_include_file()

const char* GEO::GLSL::get_GLSL_include_file ( const std::string &  name)

Gets a GLSL include file by file name.

It needs to be a real file, registered as a pointer to static text data (not a PseudoFile).

Parameters
[in]namethe name of the file in the pseudo file system.
Returns
a const pointer to the contents of the file.

◆ get_uniform_variable_array_stride()

size_t GEOGRAM_GFX_API GEO::GLSL::get_uniform_variable_array_stride ( GLuint  program,
const char *  varname 
)

Queries array stride for a variable in a GLSL program using introspection.

Parameters
[in]programthe handle of the program
[in]varnamea string with the name of the array variable
Returns
the number of bytes between two consecutive elements of the array.

◆ get_uniform_variable_offset()

GLint GEOGRAM_GFX_API GEO::GLSL::get_uniform_variable_offset ( GLuint  program,
const char *  varname 
)

Gets the offset of a uniform variable relative to the uniform block it is declared in.

Parameters
[in]programa GLSL program handle
[in]varnamethe name of the variable
Returns
the offset of the variable relative to the beginning of the uniform block it is declared in, in bytes.

◆ initialize()

void GEOGRAM_GFX_API GEO::GLSL::initialize ( )

Initializes some GLSL functions and objects.

Called by GEO::Graphics::initialize()

◆ link_program()

void GEOGRAM_GFX_API GEO::GLSL::link_program ( GLuint  program)

Links a program.

Errors are detexted and displayed to the Logger.

Parameters
[in]programthe program to be linked

◆ register_GLSL_include_file() [1/2]

void GEOGRAM_GFX_API GEO::GLSL::register_GLSL_include_file ( const std::string &  name,
const char *  source 
)

Registers a file in the GLSL pseudo file system.

The file can then be included in a GLSL source with the //include <name> directive.

Parameters
[in]namethe name of the pseudo file
[in]sourcethe GLSL source of the file

◆ register_GLSL_include_file() [2/2]

void GEOGRAM_GFX_API GEO::GLSL::register_GLSL_include_file ( const std::string &  name,
PseudoFile  file 
)

Registers a pseudo file in the GLSL pseudo file system.

The pseudo file can then be included in a GLSL source with the //include <name> directive. Each time it is included, it is generated by calling the specified function.

Parameters
[in]namethe name of the pseudo file
[in]filea pointer to a member function of an object derived from a PseudoFileProvider object that returns a string.

◆ set_program_uniform_by_name() [1/2]

bool GEO::GLSL::set_program_uniform_by_name ( GLuint  shader_id,
const char *  name,
index_t  count,
float *  values 
)
inline

Sets an array of uniform variables in a shader by name.

Parameters
[in]shader_idthe handle to the GLSL shader
[in]namethe name of the uniform variable, as specified in the GLSL source of the shader.
[in]countnumber of values
[in]valuesa pointer to an array of values of size count

Definition at line 513 of file GLSL.h.

◆ set_program_uniform_by_name() [2/2]

template<class T >
bool GEO::GLSL::set_program_uniform_by_name ( GLuint  shader_id,
const char *  name,
val 
)
inline

Sets a uniform variable in a shader by name.

Parameters
[in]shader_idthe handle to the GLSL shader
[in]namethe name of the uniform variable, as specified in the GLSL source of the shader.
[in]valthe value of the parameter
Template Parameters
Tthe type of the parameter. Needs to match the type of the uniform parameter in the GLSL source.

Definition at line 425 of file GLSL.h.

◆ supported_language_version()

double GEOGRAM_GFX_API GEO::GLSL::supported_language_version ( )

Gets the supported GLSL language version.

The supported GLSL version is determined from hardware/driver capabilities and user-defined parameters.

◆ terminate()

void GEOGRAM_GFX_API GEO::GLSL::terminate ( )

Terminates GLSL functions and objects.

Called by GEO::Graphics::terminate()