- return the specified pixel map
C SPECIFICATION
PARAMETERS
_param1 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.
_param2 Returns the pixel map contents.
DESCRIPTION
See the glPixelMap reference page for a description of the
acceptable values for the _param1 parameter.
glGetPixelMap returns in _param2 the contents of the pixel
map specified in _param1. Pixel maps are used during the
execution of glReadPixels, glDrawPixels, glCopyPixels,
glTexImage1D, glTexImage2D, glTexImage3D, glTexSubImage1D,
glTexSubImage2D, glTexSubImage3D, glCopyTexImage1D,
glCopyTexImage2D, glCopyTexSubImage1D,
glCopyTexSubImage2D, glCopyTexSubImage3D, glColorTable,
glColorSubTable, glCopyColorTable, glCopyColorSubTable,
glConvolutionFilter1D, glConvolutionFilter2D,
glSeparableFilter2D, glGetHistogram, glGetMinmax, and
glGetTexImage 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 _param1, call glGet with
the appropriate symbolic constant.
NOTES
If an error is generated, no change is made to the con-
tents of _param2.
ERRORS
GL_INVALID_ENUM is generated if _param1 is not an accepted
value.
GL_INVALID_OPERATION is generated if glGetPixelMap is exe-
cuted between the execution of glBegin and the correspond-
ing execution of glEnd.
glColorSubTable, glColorTable, glConvolutionFilter1D,
glConvolutionFilter2D, glCopyColorSubTable,
glCopyColorTable, glCopyPixels, glCopyTexImage1D,
glCopyTexImage2D, glCopyTexSubImage1D,
glCopyTexSubImage2D, glCopyTexSubImage3D, glDrawPixels,
glGetHistogram, glGetMinmax, glGetTexImage, glPixelMap,
glPixelTransfer, glReadPixels, glSeparableFilter2D,
glTexImage1D, glTexImage1D, glTexImage2D glTexImage2D,
glTexImage3D, glTexSubImage1D, glTexSubImage2D,
glTexSubImage3D
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