glGetPixelMapfv, glGetPixelMapuiv, glGetPixelMapusv

These functions return the specified pixel map.

void glGetPixelMapfv(
  GLenum map,
  GLfloat *values
);

void glGetPixelMapuiv(
  GLenum map,
  GLuint *values
);

void 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.

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

Error Codes

The following are the error codes generated and their conditions.

Error code Condition
GL_INVALID_ENUM map was not an accepted value.
GL_INVALID_OPERATION glGetPixelMap was called between a call to glBegin and the corresponding call to glEnd.

Requirements

  Windows NT/2000: Requires Windows NT 3.5 or later.
  Windows 95/98: Requires Windows 95 or later. Available as a redistributable for Windows 95.
  Header: Declared in Gl.h.
  Library: Use Opengl32.lib.

See Also

glBegin, glCopyPixels, glDrawPixels, glEnd, glGet, glPixelMap, glPixelTransfer, glReadPixels, glTexImage1D, glTexImage2D


  

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