glGetColorTableParameter

Name

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.