- 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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