---
name: "glIndexMask"
section: "3x"
platform: "linux"
package: "xlibmesa-gl-dev"
version: "4.3.0.dfsg.1-14sarge7"
release: "Debian 3.1 (Sarge)"
platforms: ["linux"]
url: "https://new.carta.tech/glIndexMask"
---

# glIndexMask(3x)

control the writing of individual bits in the color index buffers

## NAME

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

## C SPECIFICATION

void **glIndexMask**( GLuint *mask* )

```

```

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## 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(3G)**, **glDepthMask(3G)**, **glDrawBuffer(3G)**, **glIndex(3G)**, **glIndexPointer(3G)**, **glStencilMask(3G)**