GLGETCOLORTABLE(3G)

NAME
glGetColorTable - retrieve contents of a color lookup table

C SPECIFICATION

void glGetColorTable(GLenum target, GLenum format, GLenum type, GLvoid * table);

PARAMETERS

target
    Must be GL_COLOR_TABLE, GL_POST_CONVOLUTION_COLOR_TABLE, or GL_POST_COLOR_MATRIX_COLOR_TABLE.

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_BGR, GL_RGBA, and GL_BGRA.

type
    The type of the pixel data in table. Symbolic constants GL_UNSIGNED_BYTE, GL_BYTE, GL_BITMAP, GL_UNSIGNED_SHORT, GL_SHORT, GL_UNSIGNED_INT, GL_INT, GL_FLOAT, GL_UNSIGNED_BYTE_3_3_2, GL_UNSIGNED_BYTE_2_3_3_REV, GL_UNSIGNED_SHORT_5_6_5, GL_UNSIGNED_SHORT_5_6_5_REV, GL_UNSIGNED_SHORT_4_4_4_4, GL_UNSIGNED_SHORT_4_4_4_4_REV, GL_UNSIGNED_SHORT_5_5_5_1, GL_UNSIGNED_SHORT_1_5_5_5_REV, GL_UNSIGNED_INT_8_8_8_8, GL_UNSIGNED_INT_8_8_8_8_REV, GL_UNSIGNED_INT_10_10_10_2, and GL_UNSIGNED_INT_2_10_10_10_REV are accepted.

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

DESCRIPTION

glGetColorTable 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 glReadPixels() are performed.

If a non-zero named buffer object is bound to the GL_PIXEL_PACK_BUFFER target (see glBindBuffer()) while a histogram table is requested, table is treated as a byte offset into the buffer object's data store.

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

glGetColorTable is present only if ARB_imaging is returned when glGetString() is called with an argument of GL_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 type is one of GL_UNSIGNED_BYTE_3_3_2, GL_UNSIGNED_BYTE_2_3_3_REV, GL_UNSIGNED_SHORT_5_6_5, or GL_UNSIGNED_SHORT_5_6_5_REV and format is not GL_RGB.

GL_INVALID_OPERATION is generated if type is one of GL_UNSIGNED_SHORT_4_4_4_4, GL_UNSIGNED_SHORT_4_4_4_4_REV, GL_UNSIGNED_SHORT_5_5_5_1, GL_UNSIGNED_SHORT_1_5_5_5_REV, GL_UNSIGNED_INT_8_8_8_8, GL_UNSIGNED_INT_8_8_8_8_REV, GL_UNSIGNED_INT_10_10_10_2, or GL_UNSIGNED_INT_2_10_10_10_REV and format is neither GL_RGBA nor GL_BGRA.

GL_INVALID_OPERATION is generated if a non-zero buffer object name is bound to the GL_PIXEL_PACK_BUFFER target and the buffer object's data store is currently mapped.

GL_INVALID_OPERATION is generated if a non-zero buffer object name is bound to the GL_PIXEL_PACK_BUFFER target and the data would be packed to the buffer object such that the memory writes required would exceed the data store size.

GL_INVALID_OPERATION is generated if a non-zero buffer object name is bound to the GL_PIXEL_PACK_BUFFER target and table is not evenly divisible into the number of bytes needed to store in memory a datum indicated by type.

GL_INVALID_OPERATION is generated if glGetColorTable is executed between the execution of glBegin() and the corresponding execution of glEnd().

ASSOCIATED GETS

glGetColorTableParameter()

glGet() with argument GL_PIXEL_PACK_BUFFER_BINDING

SEE ALSO

glColorTable(), glColorTableParameter()

COPYRIGHT

Copyright © 1991-2006 Silicon Graphics, Inc. This document is licensed under the SGI Free Software B License. For details, see http://oss.sgi.com/projects/FreeB/.

AUTHORS

opengl.org