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glGetColorTable — retrieve contents of a color lookup table
void glGetColorTable( | GLenum | target, |
| GLenum | format, | |
| GLenum | type, | |
| GLvoid * | table); |
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.
tablePointer to a one-dimensional array of pixel data containing the contents of the color table.
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 |
glGetColorTable 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 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.
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/.