glIsEnabled(3G)

NAME
     glIsEnabled - test whether a capability is enabled


C SPECIFICATION
     GLboolean glIsEnabled( GLenum cap )


PARAMETERS
     cap  Specifies a symbolic constant indicating a GL capability.

DESCRIPTION
     glIsEnabled returns GL_TRUE if cap is an enabled capability and returns
     GL_FALSE otherwise.  Initially all capabilities except GL_DITHER are
     disabled; GL_DITHER is initially enabled.

     The following capabilities are accepted for cap:

     GL_ALPHA_TEST                          See glAlphaFunc.
     GL_AUTO_NORMAL                         See glEvalCoord.
     GL_BLEND                               See glBlendFunc.
     GL_CALLIGRAPHIC_FRAGMENT_SGIX
     GL_CLIP_PLANEi                         See glClipPlane.
     GL_COLOR_ARRAY                         See glColorPointer.
     GL_COLOR_ARRAY_EXT                     See glColorPointerEXT.
     GL_COLOR_LOGIC_OP                      See glLogicOp.
     GL_COLOR_MATERIAL                      See glColorMaterial.
     GL_COLOR_TABLE_SGI                     See glColorTableSGI.
     GL_CONVOLUTION_1D_EXT                  See glConvolutionFilter1DEXT.
     GL_CONVOLUTION_2D_EXT                  See glConvolutionFilter2DEXT.
     GL_CULL_FACE                           See glCullFace.
     GL_DEPTH_TEST                          See glDepthFunc and  glDepthRange.
     GL_DITHER                              See glEnable.
     GL_EDGE_FLAG_ARRAY                     See glEdgeFlagPointer.
     GL_EDGE_FLAG_ARRAY_EXT                 See glEdgeFlagPointerEXT.
     GL_FOG                                 See glFog.
     GL_FOG_OFFSET_SGIX                     See glFog.
     GL_HISTOGRAM_EXT                       See glHistogramEXT.
     GL_INDEX_ARRAY                         See glIndexPointer.
     GL_INDEX_ARRAY_EXT                     See glIndexPointerEXT.
     GL_INDEX_LOGIC_OP                      See glLogicOp.
     GL_INTERLACE_SGIX                      See glCopyPixels and glCopyTexSubImage2DEXT.
     GL_IR_INSTRUMENT1_SGIX                 See glInstrumentsBufferSGIX.
     GL_LIGHTi                              See glLightModel and glLight.
     GL_LIGHTING                            See glMaterial, glLightModel, and glLight.
     GL_LINE_SMOOTH                         See glLineWidth.
     GL_LINE_STIPPLE                        See glLineStipple.
     GL_LOGIC_OP                            See glLogicOp.
     GL_MAP1_COLOR_4                        See glMap1.
     GL_MAP1_INDEX                          See glMap1.
     GL_MAP1_NORMAL                         See glMap1.
     GL_MAP1_TEXTURE_COORD_1                See glMap1.
     GL_MAP1_TEXTURE_COORD_2                See glMap1.
     GL_MAP1_TEXTURE_COORD_3                See glMap1.
     GL_MAP1_TEXTURE_COORD_4                See glMap1.
     GL_MAP1_VERTEX_3                       See glMap1.
     GL_MAP1_VERTEX_4                       See glMap1.
     GL_MAP2_COLOR_4                        See glMap2.
     GL_MAP2_INDEX                          See glMap2.
     GL_MAP2_NORMAL                         See glMap2.
     GL_MAP2_TEXTURE_COORD_1                See glMap2.
     GL_MAP2_TEXTURE_COORD_2                See glMap2.
     GL_MAP2_TEXTURE_COORD_3                See glMap2.
     GL_MAP2_TEXTURE_COORD_4                See glMap2.
     GL_MAP2_VERTEX_3                       See glMap2.
     GL_MAP2_VERTEX_4                       See glMap2.
     GL_MINMAX_EXT                          See glMinmaxEXT.
     GL_MULTISAMPLE_SGIS                    See glSamplePatternSGIS, glSampleMaskSGIS.
     GL_NORMAL_ARRAY                        See glNormalPointer.
     GL_NORMAL_ARRAY_EXT                    See glNormalPointerEXT.
     GL_NORMALIZE                           See glNormal.
     GL_POINT_SMOOTH                        See glPointSize.
     GL_POLYGON_OFFSET_EXT                  See glPolygonOffsetEXT.
     GL_POLYGON_OFFSET_FILL                 See glPolygonOffset.
     GL_POLYGON_OFFSET_LINE                 See glPolygonOffset.
     GL_POLYGON_OFFSET_POINT                See glPolygonOffset.
     GL_POLYGON_SMOOTH                      See glPolygonMode.
     GL_POLYGON_STIPPLE                     See glPolygonStipple.
     GL_POST_COLOR_MATRIX_COLOR_TABLE_SGI   See glColorTableSGI.
     GL_POST_CONVOLUTION_COLOR_TABLE_SGI    See glColorTableSGI.
     GL_REFERENCE_PLANE_SGIX                See glReferencePlaneSGIX.
     GL_SAMPLE_ALPHA_TO_MASK_SGIS           See glSampleMaskSGIS.
     GL_SAMPLE_ALPHA_TO_ONE_SGIS            See glSampleMaskSGIS.
     GL_SAMPLE_MASK_SGIS                    See glSampleMaskSGIS.
     GL_SCISSOR_TEST                        See glScissor.
     GL_SEPARABLE_2D_EXT                    See glSeparableFilter2DEXT.
     GL_SPRITE_SGIX                         See glSpriteParameterSGIX.
     GL_STENCIL_TEST                        See glStencilFunc and glStencilOp.
     GL_TEXTURE_1D                          See glTexImage1D.
     GL_TEXTURE_2D                          See glTexImage2D.
     GL_TEXTURE_3D_EXT                      See glTexImage3DEXT.
     GL_TEXTURE_COLOR_TABLE_SGI             See glColorTableSGI.
     GL_TEXTURE_COORD_ARRAY                 See glTexCoordPointer.
     GL_TEXTURE_COORD_ARRAY_EXT             See glTexCoordPointerEXT.
     GL_TEXTURE_GEN_Q                       See glTexGen.
     GL_TEXTURE_GEN_R                       See glTexGen.
     GL_TEXTURE_GEN_S                       See glTexGen.
     GL_TEXTURE_GEN_T                       See glTexGen.
     GL_VERTEX_ARRAY                        See glVertexPointer.
     GL_VERTEX_ARRAY_EXT                    See glVertexPointerEXT.
NOTES
     If an error is generated, glIsEnabled returns zero.

     GL_COLOR_LOGIC_OP, GL_COLOR_ARRAY, GL_EDGE_FLAG_ARRAY, GL_INDEX_ARRAY,
     GL_INDEX_LOGIC_OP, GL_NORMAL_ARRAY, GL_POLYGON_OFFSET_FILL,
     GL_POLYGON_OFFSET_LINE, GL_POLYGON_OFFSET_POINT, GL_TEXTURE_COORD_ARRAY,
     and GL_VERTEX_ARRAY are only available if the GL version is 1.1 or
     greater

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

     GL_INVALID_OPERATION is generated if glIsEnabled is executed between the
     execution of glBegin and the corresponding execution of glEnd.


MACHINE DEPENDENCIES
     GL_COLOR_TABLE_SGI, GL_POST_COLOR_MATRIX_COLOR_TABLE_SGI and
     GL_POST_CONVOLUTION_COLOR_TABLE_SGI are part of the SGI_color_table
     extension which is not supported on RealityEngine, RealityEngine2, and
     VTX systems.

     The SGIX_interlace extension is supported only on InfiniteReality
     systems, on RealityEngine, RealityEngine2, and VTX systems, and on O2
     systems.


SEE ALSO
     glEnable glEnableClientState