glPixelMap — set up pixel transfer maps
void glPixelMapfv( | GLenum | map, |
GLsizei | mapsize, | |
const GLfloat * | values) ; |
void glPixelMapuiv( | GLenum | map, |
GLsizei | mapsize, | |
const GLuint * | values) ; |
void glPixelMapusv( | GLenum | map, |
GLsizei | mapsize, | |
const GLushort * | values) ; |
map
Specifies a symbolic map name.
Must be one of the following:
GL_PIXEL_MAP_I_TO_I
,
GL_PIXEL_MAP_S_TO_S
,
GL_PIXEL_MAP_I_TO_R
,
GL_PIXEL_MAP_I_TO_G
,
GL_PIXEL_MAP_I_TO_B
,
GL_PIXEL_MAP_I_TO_A
,
GL_PIXEL_MAP_R_TO_R
,
GL_PIXEL_MAP_G_TO_G
,
GL_PIXEL_MAP_B_TO_B
, or
GL_PIXEL_MAP_A_TO_A
.
mapsize
Specifies the size of the map being defined.
values
Specifies an array of mapsize
values.
glPixelMap
sets up translation tables,
or maps,
used by
glCopyPixels,
glCopyTexImage1D,
glCopyTexImage2D,
glCopyTexSubImage1D,
glCopyTexSubImage2D,
glCopyTexSubImage3D,
glDrawPixels,
glReadPixels,
glTexImage1D,
glTexImage2D,
glTexImage3D,
glTexSubImage1D,
glTexSubImage2D, and
glTexSubImage3D.
Additionally, if the ARB_imaging
subset is supported, the
routines
glColorTable,
glColorSubTable,
glConvolutionFilter1D,
glConvolutionFilter2D,
glHistogram,
glMinmax, and
glSeparableFilter2D.
Use of these maps is described completely in the
glPixelTransfer reference page,
and partly in the reference pages for the pixel and texture image commands.
Only the specification of the maps is described in this reference page.
map
is a symbolic map name,
indicating one of ten maps to set.
mapsize
specifies the number of entries in the map,
and values
is a pointer to an array of mapsize
map values.
If a non-zero named buffer object is bound to the GL_PIXEL_UNPACK_BUFFER
target
(see glBindBuffer) while a pixel transfer map is
specified, values
is treated as a byte offset into the buffer object's data store.
The ten maps are as follows:
GL_PIXEL_MAP_I_TO_I
Maps color indices to color indices.
GL_PIXEL_MAP_S_TO_S
Maps stencil indices to stencil indices.
GL_PIXEL_MAP_I_TO_R
Maps color indices to red components.
GL_PIXEL_MAP_I_TO_G
Maps color indices to green components.
GL_PIXEL_MAP_I_TO_B
Maps color indices to blue components.
GL_PIXEL_MAP_I_TO_A
Maps color indices to alpha components.
GL_PIXEL_MAP_R_TO_R
Maps red components to red components.
GL_PIXEL_MAP_G_TO_G
Maps green components to green components.
GL_PIXEL_MAP_B_TO_B
Maps blue components to blue components.
GL_PIXEL_MAP_A_TO_A
Maps alpha components to alpha components.
The entries in a map can be specified as single-precision
floating-point numbers,
unsigned short integers,
or unsigned int integers.
Maps that store color component values
(all but GL_PIXEL_MAP_I_TO_I
and GL_PIXEL_MAP_S_TO_S
)
retain their values in floating-point format,
with unspecified mantissa and exponent sizes.
Floating-point values specified by glPixelMapfv
are converted directly
to the internal floating-point format of these maps,
then clamped to the range [0,1].
Unsigned integer values specified by glPixelMapusv
and
glPixelMapuiv
are converted linearly such that
the largest representable integer maps to 1.0,
and 0 maps to 0.0.
Maps that store indices,
GL_PIXEL_MAP_I_TO_I
and GL_PIXEL_MAP_S_TO_S
,
retain their values in fixed-point format,
with an unspecified number of bits to the right of the binary point.
Floating-point values specified by glPixelMapfv
are converted directly
to the internal fixed-point format of these maps.
Unsigned integer values specified by glPixelMapusv
and
glPixelMapuiv
specify integer values,
with all 0's to the right of the binary point.
The following table shows the initial sizes and values for each of the maps.
Maps that are indexed by either color or stencil indices must have
mapsize
=
GL_MAX_PIXEL_MAP_TABLE
.
The single maximum applies to all maps; it is at
least 32.
map
| Lookup Index | Lookup Value | Initial Size | Initial Value |
---|---|---|---|---|
GL_PIXEL_MAP_I_TO_I
| color index | color index | 1 | 0 |
GL_PIXEL_MAP_S_TO_S
| stencil index | stencil index | 1 | 0 |
GL_PIXEL_MAP_I_TO_R
| color index | R | 1 | 0 |
GL_PIXEL_MAP_I_TO_G
| color index | G | 1 | 0 |
GL_PIXEL_MAP_I_TO_B
| color index | B | 1 | 0 |
GL_PIXEL_MAP_I_TO_A
| color index | A | 1 | 0 |
GL_PIXEL_MAP_R_TO_R
| R | R | 1 | 0 |
GL_PIXEL_MAP_G_TO_G
| G | G | 1 | 0 |
GL_PIXEL_MAP_B_TO_B
| B | B | 1 | 0 |
GL_PIXEL_MAP_A_TO_A
| A | A | 1 | 0 |
GL_INVALID_ENUM
is generated if map
is not an accepted value.
GL_INVALID_VALUE
is generated if mapsize
is less than one
or larger than GL_MAX_PIXEL_MAP_TABLE
.
GL_INVALID_VALUE
is generated if map
is
GL_PIXEL_MAP_I_TO_I
,
GL_PIXEL_MAP_S_TO_S
,
GL_PIXEL_MAP_I_TO_R
,
GL_PIXEL_MAP_I_TO_G
,
GL_PIXEL_MAP_I_TO_B
, or
GL_PIXEL_MAP_I_TO_A
,
and mapsize
is not a power of two.
GL_INVALID_OPERATION
is generated if a non-zero buffer object name is bound to the
GL_PIXEL_UNPACK_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_UNPACK_BUFFER
target and the data would be unpacked from the buffer
object such that the memory reads required would exceed the data store size.
GL_INVALID_OPERATION
is generated by glPixelMapfv
if a non-zero buffer object name is bound to the
GL_PIXEL_UNPACK_BUFFER
target and values
is not evenly divisible
into the number of bytes needed to store in memory a GLfloat datum.
GL_INVALID_OPERATION
is generated by glPixelMapuiv
if a non-zero buffer object name is bound to the
GL_PIXEL_UNPACK_BUFFER
target and values
is not evenly divisible
into the number of bytes needed to store in memory a GLuint datum.
GL_INVALID_OPERATION
is generated by glPixelMapusv
if a non-zero buffer object name is bound to the
GL_PIXEL_UNPACK_BUFFER
target and values
is not evenly divisible
into the number of bytes needed to store in memory a GLushort datum.
GL_INVALID_OPERATION
is generated if glPixelMap
is executed between the execution of glBegin
and the corresponding execution of glEnd.
glGet with argument GL_PIXEL_MAP_I_TO_I_SIZE
glGet with argument GL_PIXEL_MAP_S_TO_S_SIZE
glGet with argument GL_PIXEL_MAP_I_TO_R_SIZE
glGet with argument GL_PIXEL_MAP_I_TO_G_SIZE
glGet with argument GL_PIXEL_MAP_I_TO_B_SIZE
glGet with argument GL_PIXEL_MAP_I_TO_A_SIZE
glGet with argument GL_PIXEL_MAP_R_TO_R_SIZE
glGet with argument GL_PIXEL_MAP_G_TO_G_SIZE
glGet with argument GL_PIXEL_MAP_B_TO_B_SIZE
glGet with argument GL_PIXEL_MAP_A_TO_A_SIZE
glGet with argument GL_MAX_PIXEL_MAP_TABLE
glGet with argument GL_PIXEL_UNPACK_BUFFER_BINDING
glColorTable, glColorSubTable, glConvolutionFilter1D, glConvolutionFilter2D, glCopyPixels, glCopyTexImage1D, glCopyTexImage2D, glCopyTexSubImage1D, glCopyTexSubImage2D, glDrawPixels, glHistogram, glMinmax, glPixelStore, glPixelTransfer, glReadPixels, glSeparableFilter2D, glTexImage1D, glTexImage2D, glTexImage3D, glTexSubImage1D, glTexSubImage2D, glTexSubImage3D
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/.