G
glGetPixelMap
Chapter 7
204
glGetPixelMap
glGetPixelMapfv, glGetPixelMapuiv, glGetPixelMapusv: return the specified
pixel map.
C Specification
void glGetPixelMapfv
GLenum map
GLfloat *values
void glGetPixelMapuiv
GLenum map
GLuint *values
void glGetPixelMapusv
GLenum map
GLushort *values)
Parameters
map Specifies the name of the pixel map to return. Accepted values are
GL_PIXEL_MAP_I_TO_I, GL_PIXEL_MAP_S_TO_S,
GL_PIXEL_MAP_I_TO_R, GL_PIXEL_MAP_I_TO_G,
GL_PIXEL_MAP_I_TO_B, GL_PIXEL_MAP_I_TO_A,
GL_PIXEL_MAP_R_TO_R, GL_PIXEL_MAP_G_TO_G,
GL_PIXEL_MAP_B_TO_B, and GL_PIXEL_MAP_A_TO_A.
values Returns the pixel map contents.
Description
See the glPixelMap reference page for a description of the acceptable values for the map
parameter. glGetPixelMap returns in values the contents of the pixel map specified in
map. Pixel maps are used during the execution of glReadPixels, glDrawPixels,
glCopyPixels, glTexImage1D, and glTexImage2D to map color indices, stencil indices,
color components, and depth components to other values.
Unsigned integer values, if requested, are linearly mapped from the internal fixed or
floating-point representation such that 1.0 maps to the largest representable integer
value, and 0.0 maps to 0. Return unsigned integer values are undefined if the map value
was not in the range [0, 1].
To determine the required size of map, call glGet with the appropriate symbolic
constant.
Notes
If an error is generated, no change is made to the contents of values.
Errors
• GL_INVALID_ENUM is generated if map is not an accepted value.
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