Precaution to access user mode buffers from kernel

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LEARN ABOUT XFREE86

glindexmask

GLINDEXMASK(3G) 														   GLINDEXMASK(3G)

NAME

       glIndexMask - control the writing of individual bits in the color index buffers

C SPECIFICATION

       void glIndexMask( GLuint mask )

PARAMETERS

       mask  Specifies	a  bit	mask  to enable and disable the writing of individual bits in the color index buffers.	Initially, the mask is all
	     1's.

DESCRIPTION

       glIndexMask controls the writing of individual bits in the color index buffers.	The least significant n bits of mask, where n is the  num-
       ber  of bits in a color index buffer, specify a mask.  Where a 1 (one) appears in the mask, it's possible to write to the corresponding bit
       in the color index buffer (or buffers).	Where a 0 (zero) appears, the corresponding bit is write-protected.

       This mask is used only in color index mode, and it affects only the buffers currently selected for writing (see glDrawBuffer).	Initially,
       all bits are enabled for writing.

ERRORS

       GL_INVALID_OPERATION is generated if glIndexMask is executed between the execution of glBegin and the corresponding execution of glEnd.

ASSOCIATED GETS

       glGet with argument GL_INDEX_WRITEMASK

SEE ALSO

       glColorMask(3G), glDepthMask(3G), glDrawBuffer(3G), glIndex(3G), glIndexPointer(3G), glStencilMask(3G)

																   GLINDEXMASK(3G)

UNIX for Advanced & Expert Users