glGetColorTableParameter — get color lookup table parameters
void glGetColorTableParameterfv( | GLenum | target, |
GLenum | pname, | |
GLfloat * | params) ; |
void glGetColorTableParameteriv( | GLenum | target, |
GLenum | pname, | |
GLint * | params) ; |
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.
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 |
glGetColorTableParameter
is present only if ARB_imaging
is returned when glGetString
is called with an argument of GL_EXTENSIONS
.
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.
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/.