fglGetColorTableSGI(3G)

NAME
     fglGetColorTableSGI - retrieve contents of a color lookup table


FORTRAN SPECIFICATION
     SUBROUTINE fglGetColorTableSGI( INTEGER*4 target,
                                     INTEGER*4 format,
                                     INTEGER*4 type,
                                     CHARACTER*8 table )


PARAMETERS
     target  Must be GL_TEXTURE_COLOR_TABLE_SGI, GL_COLOR_TABLE_SGI,
             GL_POST_CONVOLUTION_COLOR_TABLE_SGI, or
             GL_POST_COLOR_MATRIX_COLOR_TABLE_SGI.

     format  The format of the pixel data in table.  The possible values are
             GL_RED, GL_GREEN, GL_BLUE, GL_ALPHA, GL_LUMINANCE,
             GL_LUMINANCE_ALPHA, GL_RGB, GL_RGBA, and GL_ABGR_EXT.

     type    The type of the pixel data in table.  The allowable values are
             GL_UNSIGNED_BYTE, GL_BYTE, GL_UNSIGNED_SHORT, GL_SHORT,
             GL_UNSIGNED_INT, GL_INT, GL_FLOAT, GL_UNSIGNED_BYTE_3_3_2_EXT,
             GL_UNSIGNED_SHORT_4_4_4_4_EXT, GL_UNSIGNED_SHORT_5_5_5_1_EXT,
             GL_UNSIGNED_INT_8_8_8_8_EXT, and GL_UNSIGNED_INT_10_10_10_2_EXT.

     table   Pointer to a one-dimensional array of pixel data containing the
             contents of the color table.

DESCRIPTION
     fglGetColorTableSGI is part of the SGI_color_table extension, and is also
     used by the SGI_texture_color_table extension.

     fglGetColorTableSGI returns in table the contents of the color table
     specified by target. No pixel transfer operations are performed, but
     pixel storage modes that are applicable to fglReadPixels are performed.

     Color components that are requested in the specified format, but which
     are not included in the internal format of the color lookup table, are
     returned as zero.  The assignments of internal color components to the
     components requested by format are

                     Internal Component   Resulting Component
                     ________________________________________
                            red                   red
                           green                 green
                            blue                 blue
                           alpha                 alpha
                         luminance                red
                         intensity                red
NOTES
     If target is set to GL_TEXTURE_COLOR_TABLE_SGI and the
     SGI_texture_color_table extension is not supported then a GL_INVALID_ENUM
     error is generated.

     If target is set to GL_COLOR_TABLE_SGI,
     GL_POST_CONVOLUTION_COLOR_TABLE_SGI, or
     GL_POST_COLOR_MATRIX_COLOR_TABLE_SGI and the SGI_color_table extension is
     not supported then an GL_INVALID_ENUM error is generated.

     If type is set to GL_UNSIGNED_BYTE_3_3_2_EXT,
     GL_UNSIGNED_SHORT_4_4_4_4_EXT, GL_UNSIGNED_SHORT_5_5_5_1_EXT,
     GL_UNSIGNED_INT_8_8_8_8_EXT, or GL_UNSIGNED_INT_10_10_10_2_EXT and the
     EXT_packed_pixels extension is not supported then an GL_INVALID_ENUM
     error is generated.

     See fglIntro for more information on using extensions.

ERRORS
     GL_INVALID_ENUM is generated if target is not one of the allowable
     values.

     GL_INVALID_ENUM is generated if format is not one of the allowable
     values.

     GL_INVALID_ENUM is generated if type is not one of the allowable values.

     GL_INVALID_OPERATION is generated if fglGetColorTableSGI is executed
     between the execution of fglBegin and the corresponding execution of
     fglEnd.


MACHINE DEPENDENCIES
     RealityEngine, RealityEngine2, and VTX systems do not support
     fglGetColorTableSGI; calling it results in a GL_INVALID_OPERATION error.


SEE ALSO
     fglColorTableSGI.  fglColorTableParameterSGI.
     fglGetColorTableParameterSGI.