index package:OpenGL

Change the current color index.
Controls the writing of individual bits in the color index buffers. The least significant n bits of its value, where n is the number of bits in a color index buffer, specify a mask. Where a 1 appears in the mask, it is possible to write to the corresponding bit in the color index buffer (or buffers). Where a 0 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 drawBuffer). Initially, all bits are enabled for writing.
A color index.
The class of all types which can be used as a color index.
The index of the draw buffer.
Controls the index c used by clear to clear the color index buffers. c is not clamped. Rather, c is converted to a fixed-point value with unspecified precision to the right of the binary point. The integer part of this value is then masked with 2^m-1, where m is the number of bits in a color index stored in the framebuffer. Initially, the value is 0.