glPixelMap, glPixelMapfv, glPixelMapuiv, glPixelMapusv -
set up pixel transfer maps
void glPixelMapfv(
GLenum map,
GLint mapsize,
const GLfloat *values ); void glPixelMapuiv(
GLenum map,
GLint mapsize,
const GLuint *values ); void glPixelMapusv(
GLenum map,
GLint mapsize,
const GLushort *values );
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. Specifies
the size of the map being defined. 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 GL_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.
The ten maps are as follows: Maps color indices to color
indices. Maps stencil indices to stencil indices. Maps
color indices to red components. Maps color indices to
green components. Maps color indices to blue components.
Maps color indices to alpha components. Maps red components
to red components. Maps green components to green
components. Maps blue components to blue components.
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 long 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
, with unspecified mantissa and exponent sizes. Floatingpoint
values specified by glPixelMapfv() are converted
directly to the internal floating-point 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 ,
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 fixedpoint
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 = 2 sup n for some n or
the results are undefined. The maximum allowable size for
each map depends on the implementation and can be determined
by calling glGet() with argument
GL_MAX_PIXEL_MAP_TABLE. The single maximum applies to all
maps; it is at least 32.
-----------------------------------------------------------------------
map Lookup Index Lookup Value Initial IniSize
tial
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 glPixelMap() is executed
between the execution of glBegin() and the corresponding
execution of glEnd().
glGetPixelMap()
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
glColorTable(3), glColorSubTable(3), glConvolutionFilter1D(3), glConvolutionFilter2D(3), glCopyPixels(3),
glCopyTexImage1D(3), glCopyTexImage2D(3), glCopyTexSubImage1D(3), glCopyTexSubImage2D(3), glDrawPixels(3), glHistogram(3), glMinmax(3), glPixelStore(3), glPixelTransfer(3), glReadPixels(3), glSeparableFilter2D(3), glTexImage1D(3), glTexImage2D(3), glTexImage3D(3), glTexSubImage1D(3), glTexSubImage2D(3), glTexSubImage3D(3)
glPixelMap(3G)
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