glStencilMaskSeparate

3G

glStencilMaskSeparate

control the front and/or back writing of individual bits in the stencil planes

# C Specification

                    void glStencilMaskSeparate
                    GLenum face
                    GLuint mask

## Parameters

`face`

- Specifies whether the front and/or back stencil writemask is updated. Three symbolic constants are valid: `GL_FRONT`, `GL_BACK`, and `GL_FRONT_AND_BACK`.

`mask`

- Specifies a bit mask to enable and disable writing of individual bits in the stencil planes. Initially, the mask is all 1's.

## Description

`glStencilMaskSeparate` controls the writing of individual bits in the stencil planes. The least significant n bits of `mask`, where n is the number of bits in the stencil buffer, specify a mask. Where a 1 appears in the mask, it's possible to write to the corresponding bit in the stencil buffer. Where a 0 appears, the corresponding bit is write-protected. Initially, all bits are enabled for writing.

There can be two separate `mask` writemasks; one affects back-facing polygons, and the other affects front-facing polygons as well as other non-polygon primitives.

glStencilMask

sets both front and back stencil writemasks to the same values, as if

glStencilMaskSeparate

were called with `face` set to `GL_FRONT_AND_BACK`.

## Errors

`GL_INVALID_ENUM` is generated if `face` is not one of the accepted tokens.

## Associated Gets

glGet

with argument `GL_STENCIL_WRITEMASK`, `GL_STENCIL_BACK_WRITEMASK`, or `GL_STENCIL_BITS`

## API Version Support

glStencilMaskSeparate

## See Also

glColorMask

,

glDepthMask

,

glStencilFunc

,

glStencilFuncSeparate

,

glStencilMask

,

glStencilOp

,

glStencilOpSeparate

## Copyright

Copyright 1991-2006 Silicon Graphics, Inc. Copyright 2010-2014 Khronos Group. This document is licensed under the SGI Free Software B License. For details, see http://oss.sgi.com/projects/FreeB/.