The glIndexMask function controls the writing of individual bits in the color-index buffers.
void glIndexMask(
GLuint mask
);
The glIndexMask function 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. Wherever a one appears in the mask, the corresponding bit in the color-index buffer (or buffers) is made writable. Where a zero appears, the 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.
The following function retrieves information related to glIndexMask:
glGet with argument GL_INDEX_WRITEMASK
The following are the error codes generated and their conditions.
| Error Code | Condition |
|---|---|
| GL_INVALID_OPERATION | glIndexMask was called between a call to glBegin and the corresponding call to glEnd. |
Windows NT: Use version 3.5 and later.
Windows: Use Windows 95 and later.
Windows CE: Unsupported.
Header: Declared in gl.h.
Import Library: Link with opengl32.lib.
glBegin, glDepthMask, glDrawBuffer, glEnd, glIndex, glStencilMask