HP Workstation c3650 OpenGL 1.1 Reference for HP-UX 11.x - Page 232

I glIndexMask glIndexMask 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 number 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, glDepthMask, glDrawBuffer, glIndex, glIndexPointer, glStencilMask 232 Chapter 9