1991-2006 Silicon Graphics, Inc.

glGetColorTableParameter

3G

glGetColorTableParameter

get color lookup table parameters

# C Specification

                    void glGetColorTableParameterfv
                    GLenum target
                    GLenum pname
                    GLfloat * params

                    void glGetColorTableParameteriv
                    GLenum target
                    GLenum pname
                    GLint * params

## Parameters

`target`

- The target color table. Must be `GL_COLOR_TABLE`, `GL_POST_CONVOLUTION_COLOR_TABLE`, `GL_POST_COLOR_MATRIX_COLOR_TABLE`, `GL_PROXY_COLOR_TABLE`, `GL_PROXY_POST_CONVOLUTION_COLOR_TABLE`, or `GL_PROXY_POST_COLOR_MATRIX_COLOR_TABLE`.

`pname`

- The symbolic name of a color lookup table parameter. Must be one of `GL_COLOR_TABLE_BIAS`, `GL_COLOR_TABLE_SCALE`, `GL_COLOR_TABLE_FORMAT`, `GL_COLOR_TABLE_WIDTH`, `GL_COLOR_TABLE_RED_SIZE`, `GL_COLOR_TABLE_GREEN_SIZE`, `GL_COLOR_TABLE_BLUE_SIZE`, `GL_COLOR_TABLE_ALPHA_SIZE`, `GL_COLOR_TABLE_LUMINANCE_SIZE`, or `GL_COLOR_TABLE_INTENSITY_SIZE`.

`params`

- A pointer to an array where the values of the parameter will be stored.

## Description

Returns parameters specific to color table `target`.

When `pname` is set to `GL_COLOR_TABLE_SCALE` or `GL_COLOR_TABLE_BIAS`, `glGetColorTableParameter` returns the color table scale or bias parameters for the table specified by `target`. For these queries, `target` must be set to `GL_COLOR_TABLE`, `GL_POST_CONVOLUTION_COLOR_TABLE`, or `GL_POST_COLOR_MATRIX_COLOR_TABLE` and `params` points to an array of four elements, which receive the scale or bias factors for red, green, blue, and alpha, in that order.

`glGetColorTableParameter` can also be used to retrieve the format and size parameters for a color table. For these queries, set `target` to either the color table target or the proxy color table target. The format and size parameters are set by

glColorTable

.

The following table lists the format and size parameters that may be queried. For each symbolic constant listed below for `pname`, `params` must point to an array of the given length and receive the values indicated.

Parameter | N | Meaning
`GL_COLOR_TABLE_FORMAT` | 1 | Internal format (e.g., `GL_RGBA`)
`GL_COLOR_TABLE_WIDTH` | 1 | Number of elements in table
`GL_COLOR_TABLE_RED_SIZE` | 1 | Size of red component, in bits
`GL_COLOR_TABLE_GREEN_SIZE` | 1 | Size of green component
`GL_COLOR_TABLE_BLUE_SIZE` | 1 | Size of blue component
`GL_COLOR_TABLE_ALPHA_SIZE` | 1 | Size of alpha component
`GL_COLOR_TABLE_LUMINANCE_SIZE` | 1 | Size of luminance component
`GL_COLOR_TABLE_INTENSITY_SIZE` | 1 | Size of intensity component

## Notes

`glGetColorTableParameter` 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` or `pname` is not an acceptable value.

`GL_INVALID_OPERATION` is generated if `glGetColorTableParameter` is executed between the execution of

glBegin

and the corresponding execution of

glEnd

.

## See Also

glColorTable

,

glTexParameter

,

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/.