glGetColorTableEXT

NAME

glGetColorTableEXT - get color table contents

C SPECIFICATION

void glGetColorTableEXT(GLenum target,
                        GLenum format
                        GLenum type
                        GLvoid *table)

PARAMETERS

target	Must be one of the following: GL_COLOR_TABLE_EXT, GL_POST_CONVOLUTION_COLOR_TABLE_EXT, GL_POST_COLOR_MATRIX_COLOR_TABLE_EXT, or GL_TEXTURE_COLOR_TABLE_EXT.
format	The format of the returned pixel data. The allowable values are GL_RED, GL_GREEN, GL_BLUE, GL_ALPHA, GL_LUMINANCE, GL_LUMINANCE_ALPHA, GL_RGB, GL_RGBA, GL_BGR_EXT, GL_BGRA_EXT, GL_422_EXT, GL_422_REV_EXT, GL_422_AVERAGE_EXT, and GL_422_REV_AVERAGE_EXT.
type	Specifies the data type for pixel data. 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_BYTE_2_3_3_REV_EXT, GL_UNSIGNED_SHORT_5_6_5_EXT, GL_UNSIGNED_SHORT_5_6_5_REV_EXT, GL_UNSIGNED_SHORT_4_4_4_4_EXT, GL_UNSIGNED_SHORT_4_4_4_4_REV_EXT, GL_UNSIGNED_SHORT_5_5_5_1_EXT, GL_UNSIGNED_SHORT_1_5_5_5_REV_EXT, GL_UNSIGNED_INT_8_8_8_8_EXT, GL_UNSIGNED_INT_8_8_8_8_REV_EXT, GL_UNSIGNED_INT_10_10_10_2_EXT, and GL_UNSIGNED_INT_2_10_10_10_REV_EXT.
table	Pointer to a onedimensional array of pixel data that is processed to build the color table.

DESCRIPTION

glGetColorTableEXT retrieves the contents of the color table specified by target. target must be GL_COLOR_TABLE_EXT, GL_POST_CONVOLUTION_COLOR_TABLE_EXT, GL_POST_COLOR_MATRIX_COLOR_TABLE_EXT, or GL_TEXTURE_COLOR_TABLE_EXT. See the reference page for glColorTableEXT for the acceptable values for the format and type parameters.

The one-dimensional color table image is returned in the memory referenced by table. No pixel transfer operations are performed on the image, but pixel storage modes that are applicable to glReadPixels are performed.

Color components that are present in format but not included in the internal format of the filter are returned as zero. The assignments of internal color components to the components of format are as follows:

Internal Component Resulting Component
Red Red
Green Green
Blue Blue
Alpha Alpha
Luminance Red
Intensity Red

Internal Component	Resulting Component
Red	Red
Green	Green
Blue	Blue
Alpha	Alpha
Luminance	Red
Intensity	Red

EXTENSIONS

Some routines and constants for this function are part of an extension, not part of the core GL command set. The following extension names must be present in the string returned by glGetString when called with argument GL_EXTENSIONS to use these routines and constants.

GL_EXT_422_pixels: GL_422_EXT, GL_422_REV_EXT, GL_422_AVERAGE_EXT, and GL_422_REV_AVERAGE_EXT are part of the EXT_422_pixels extension.
GL_EXT_bgra: GL_BGR_EXT and GL_BGRA_EXT are part of the EXT_bgra extension.
GL_EXT_color_table: glGetColorTableEXT, GL_COLOR_TABLE_EXT, GL_POST_CONVOLUTION_COLOR_TABLE_EXT, and GL_POST_COLOR_MATRIX_COLOR_TABLE_EXT are part of the EXT_color_table extension.
GL_EXT_packed_pixels: GL_UNSIGNED_BYTE_3_3_2_EXT, GL_UNSIGNED_BYTE_2_3_3_REV_EXT, GL_UNSIGNED_SHORT_5_6_5_EXT, GL_UNSIGNED_SHORT_5_6_5_REV_EXT, GL_UNSIGNED_SHORT_4_4_4_4_EXT, GL_UNSIGNED_SHORT_4_4_4_4_REV_EXT, GL_UNSIGNED_SHORT_5_5_5_1_EXT, GL_UNSIGNED_SHORT_1_5_5_5_REV_EXT, GL_UNSIGNED_INT_8_8_8_8_EXT, GL_UNSIGNED_INT_8_8_8_8_REV_EXT, GL_UNSIGNED_INT_10_10_10_2_EXT, and GL_UNSIGNED_INT_2_10_10_10_REV_EXT are part of the EXT_packed_pixels extension.
GL_EXT_texture_color_table: GL_TEXTURE_COLOR_TABLE_EXT is part of the EXT_texture_color_table extension.

ERRORS

GL_INVALID_ENUM is generated if target, format, or type is not an accepted value.

GL_INVALID_OPERATION is generated if glGetColorTableEXT is executed between the execution of glBegin and the corresponding execution of glEnd.