Интерактивная система просмотра системных руководств (man-ов)
glPixelMap (3)
>> glPixelMap (3) ( Разные man: Библиотечные вызовы )
NAME
glPixelMapfv, glPixelMapuiv, glPixelMapusv
- set up pixel transfer maps
C SPECIFICATION
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 )
delim $$
PARAMETERS
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.
DESCRIPTION
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:
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 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.
Floating-point 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 fixed-point 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 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
ERRORS
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.
ASSOCIATED GETS
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
