glGetPixelMapusv function

Artikkel
03/09/2021

The glGetPixelMapfv, glGetPixelMapuiv, and glGetPixelMapusv functions return the specified pixel map.

Syntax

void WINAPI glGetPixelMapusv(
   GLenum   map,
   GLushort *values
);

Parameters

map: The name of the pixel map to return. Accepted values are 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, and GL_PIXEL_MAP_A_TO_A.
values: Returns the pixel map contents.

Return value

This function does not return a value.

Error codes

The following error codes can be retrieved by the glGetError function.

Name	Meaning
GL_INVALID_ENUM	map was not an accepted value.
GL_INVALID_OPERATION	The function was called between a call to glBegin and the corresponding call to glEnd.

Remarks

See glPixelMap for a description of the acceptable values for the map parameter. The glGetPixelMap function returns in values the contents of the pixel map specified in map. Use pixel maps during the execution of glReadPixels, glDrawPixels, glCopyPixels, glTexImage1D, and glTexImage2D to map color indexes, stencil indexes, color components, and depth components to other values.

Unsigned integer values, if requested, are linearly mapped from the internal fixed or floating-point representation such that 1.0 maps to the largest representable integer value, and 0.0 maps to zero. Return unsigned integer values are undefined if the map value was not in the range [0,1].

To determine the required size of map, call glGet with the appropriate symbolic constant.

If an error is generated, no change is made to the contents of values.

The following functions retrieve information related to 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

Requirements

Requirement	Value
Minimum supported client	Windows 2000 Professional [desktop apps only]
Minimum supported server	Windows 2000 Server [desktop apps only]
Header	Gl.h
Library	Opengl32.lib
DLL	Opengl32.dll

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