HP Workstation zx2000 OpenGL 1.1 Reference for HP-UX 11.x - Page 325

P glPixelMap GL_PIXEL_MAP_I_TO_R Maps color indices to red components. GL_PIXEL_MAP_I_TO_G Maps color indices to green components. GL_PIXEL_MAP_I_TO_B Maps color indices to blue components. GL_PIXEL_MAP_I_TO_A Maps color indices to alpha components. GL_PIXEL_MAP_R_TO_R Maps red components to red components. GL_PIXEL_MAP_G_TO_G Maps green components to green components. GL_PIXEL_MAP_B_TO_B Maps blue components to blue components. GL_PIXEL_MAP_A_TO_A Maps alpha components to alpha components. The entries in a map can be specified as single-precision floating-point numbers, unsigned short integers, or unsigned long integers. Maps that store color component values (all but GL_PIXEL_MAP_I_TO_I and GL_PIXEL_MAP_S_TO_S) retain their values in floating-point format, with unspecified mantissa and exponent sizes. Floating-point values specified by glPixelMapfv are converted directly to the internal floating-point format of these maps, then clamped to the range [0, 1]. Unsigned integer values specified by glPixelMapusv and glPixelMapuiv are converted linearly such that the largest representable integer maps to 1.0, and 0 maps to 0.0. Maps that store indices, GL_PIXEL_MAP_I_TO_I and GL_PIXEL_MAP_S_TO_S, retain their values in fixed-point format, with an unspecified number of bits to the right of the binary point. Floating-point values specified by glPixelMapfv are converted directly to the internal fixed-point format of these maps. Unsigned integer values specified by glPixelMapusv and glPixelMapuiv specify integer values, with all 0s to the right of the binary point. The following table shows the initial sizes and values for each of the maps. Maps that are indexed by either color or stencil indices must have mapsize = 2n for some n or the results are undefined. The maximum allowable size for each map depends on the implementation and can be determined by calling glGet with argument GL_MAX_PIXEL_MAP_TABLE. The single maximum applies to all maps; it is at least 32. Chapter 14 325