1991-2006
Silicon Graphics, Inc.
2010-2013
Khronos Group
glIsEnabled
3G

# glIsEnabled, glIsEnabledi

test whether a capability is enabled

## C Specification

                    GLboolean glIsEnabled
                    GLenum cap

                    GLboolean glIsEnabledi
                    GLenum cap
                    GLuint index

## Parameters

`cap`

  Specifies a symbolic constant indicating a GL capability.

`index`

  Specifies the index of the capability.

## Description

`glIsEnabled` returns `GL_TRUE` if `cap` is an enabled capability and returns `GL_FALSE` otherwise. Boolean states that are indexed may be tested with `glIsEnabledi`. For `glIsEnabledi`, `index` specifies the index of the capability to test. `index` must be between zero and the count of indexed capabilities for `cap`. Initially all capabilities except `GL_DITHER` are disabled; `GL_DITHER` is initially enabled.

The following capabilities are accepted for `cap`:

Constant | See
--- | ---
`GL_BLEND` | glBlendFunc, glLogicOp
`GL_CLIP_DISTANCE` i | glEnable
`GL_COLOR_LOGIC_OP` | glLogicOp
`GL_CULL_FACE` | glCullFace
`GL_DEPTH_CLAMP` | glEnable
`GL_DEBUG_OUTPUT` | glEnable
`GL_DEBUG_OUTPUT_SYNCHRONOUS` | glEnable
`GL_DEPTH_TEST` | glDepthFunc, glDepthRange
`GL_DITHER` | glEnable
`GL_FRAMEBUFFER_SRGB` | glEnable
`GL_LINE_SMOOTH` | glLineWidth
`GL_MULTISAMPLE` | glSampleCoverage
`GL_POLYGON_SMOOTH` | glPolygonMode
`GL_POLYGON_OFFSET_FILL` | glPolygonOffset
`GL_POLYGON_OFFSET_LINE` | glPolygonOffset
`GL_POLYGON_OFFSET_POINT` | glPolygonOffset
`GL_PROGRAM_POINT_SIZE` | glEnable
`GL_PRIMITIVE_RESTART` | glEnable, glPrimitiveRestartIndex
`GL_SAMPLE_ALPHA_TO_COVERAGE` | glSampleCoverage
`GL_SAMPLE_ALPHA_TO_ONE` | glSampleCoverage
`GL_SAMPLE_COVERAGE` | glSampleCoverage
`GL_SAMPLE_MASK` | glEnable
`GL_SCISSOR_TEST` | glScissor
`GL_STENCIL_TEST` | glStencilFunc, glStencilOp
`GL_TEXTURE_CUBE_MAP_SEAMLESS` | glEnable

## Notes

If an error is generated, `glIsEnabled` and `glIsEnabledi` return `GL_FALSE`.

`GL_DEBUG_OUTPUT` and `GL_DEBUG_OUTPUT_SYNCHRONOUS` are available only if the GL version is 4.3 or greater.

## Errors

`GL_INVALID_ENUM` is generated if `cap` is not an accepted value.

`GL_INVALID_VALUE` is generated by `glIsEnabledi` if `index` is outside the valid range for the indexed state `cap`.

## See Also

glEnable, glDisable, glGet

## Copyright

Copyright 1991-2006 Silicon Graphics, Inc. Copyright 2010-2013 Khronos Group. This document is licensed under the SGI Free Software B License. For details, see http://oss.sgi.com/projects/FreeB/.