GLAF
OpenGL Advanced Functionality

Back to documentation index


Histogram availability test

GLboolean glaf_IsHistogramSupported(void)

This function returns GL_TRUE if the feature is supported or GL_FALSE otherwise. Calling the functions of an unsupported feature or using its enumerants may crash the application, or generate OpenGL errors, or even undefined behaviour, so you should never use a feature without testing its availability first.
 

Histogram support rules

  • If we're running in OpenGL 1.2 or higher, and GL_ARB_imaging is supported, and the query of the address of the imaging functions is successful, the ARB imaging implementation is used.
  • Otherwise, if GL_EXT_histogram is supported, and the query of the address of the extension functions is successful, this extension is used.
  • Otherwise, the feature is unsupported.


Histogram enumerants

(Add either a 'GLAF_' or 'GL_' prefix before each enumerant. GLAF enumerants are always defined, while GL ones depend on the version of your include files).

HISTOGRAM 
PROXY_HISTOGRAM 
HISTOGRAM_WIDTH 
HISTOGRAM_FORMAT 
HISTOGRAM_RED_SIZE 
HISTOGRAM_GREEN_SIZE 
HISTOGRAM_BLUE_SIZE 
HISTOGRAM_ALPHA_SIZE 
HISTOGRAM_LUMINANCE_SIZE 
HISTOGRAM_SINK 
MINMAX 
MINMAX_FORMAT 
MINMAX_SINK 
TABLE_TOO_LARGE 
 

Histogram functions

glaf_Histogram
glaf_ResetHistogram
glaf_GetHistogram
glaf_GetHistogramParameterfv
glaf_GetHistogramParameteriv
glaf_Minmax
glaf_ResetMinmax
glaf_GetMinmax
glaf_GetMinmaxParameterfv
glaf_GetMinmaxParameteriv
 

Histogram definitions in 'gl2glaf.h' (optional)

#define glHistogram                     glaf_Histogram
#define glResetHistogram                glaf_ResetHistogram
#define glGetHistogram                  glaf_GetHistogram
#define glGetHistogramParameterfv       glaf_GetHistogramParameterfv
#define glGetHistogramParameteriv       glaf_GetHistogramParameteriv
#define glMinmax                        glaf_Minmax
#define glResetMinmax                   glaf_ResetMinmax
#define glGetMinmax                     glaf_GetMinmax
#define glGetMinmaxParameterfv          glaf_GetMinmaxParameterfv
#define glGetMinmaxParameteriv          glaf_GetMinmaxParameteriv
 

Histogram side effects

None.

Back to documentation index
 

Copyright (C) 2001 César Blecua Udías