glIsEnabled(3)

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:

       ---------------------------------------------------------------------
       Constant                           See
       ---------------------------------------------------------------------
       GL_ALPHA_TEST                      glAlphaFunc
       GL_AUTO_NORMAL                     glEvalCoord
       GL_BLEND                           glBlendFunc, glLogicOp
       GL_CLIP_PLANEi                     glClipPlane
       GL_COLOR_ARRAY                     glColorPointer
       GL_COLOR_LOGIC_OP                  glLogicOp
       GL_COLOR_MATERIAL                  glColorMaterial
       GL_COLOR_TABLE                     glColorTable
       GL_CONVOLUTION_1D                  glConvolutionFilter1D
       GL_CONVOLUTION_2D                  glConvolutionFilter2D
       GL_CULL_FACE                       glCullFace
       GL_DEPTH_TEST                      glDepthFunc, glDepthRange
       GL_DITHER                          glEnable
       GL_EDGE_FLAG_ARRAY                 glEdgeFlagPointer
       GL_FOG                             glFog
       GL_HISTOGRAM                       glHistogram
       GL_INDEX_ARRAY                     glIndexPointer
       GL_INDEX_LOGIC_OP                  glLogicOp
       GL_LIGHTi                          glLightModel, glLight
       GL_LIGHTING                        glMaterial, glLightModel, glLight
       GL_LINE_SMOOTH                     glLineWidth
       GL_LINE_STIPPLE                    glLineStipple
       GL_MAP1_COLOR_4                    glMap1
       GL_MAP1_INDEX                      glMap1
       GL_MAP1_NORMAL                     glMap1
       GL_MAP1_TEXTURE_COORD_1            glMap1
       GL_MAP1_TEXTURE_COORD_2            glMap1
       GL_MAP1_TEXTURE_COORD_3            glMap1
       GL_MAP1_TEXTURE_COORD_4            glMap1
       GL_MAP2_COLOR_4                    glMap2
       GL_MAP2_INDEX                      glMap2
       GL_MAP2_NORMAL                     glMap2
       GL_MAP2_TEXTURE_COORD_1            glMap2
       GL_MAP2_TEXTURE_COORD_2            glMap2
       GL_MAP2_TEXTURE_COORD_3            glMap2
       GL_MAP2_TEXTURE_COORD_4            glMap2
       GL_MAP2_VERTEX_3                   glMap2
       GL_MAP2_VERTEX_4                   glMap2

       GL_MINMAX                          glMinmax
       GL_NORMAL_ARRAY                    glNormalPointer
       GL_NORMALIZE                       glNormal
       GL_POINT_SMOOTH                    glPointSize
       GL_POLYGON_SMOOTH                  glPolygonMode
       GL_POLYGON_OFFSET_FILL             glPolygonOffset
       GL_POLYGON_OFFSET_LINE             glPolygonOffset
       GL_POLYGON_OFFSET_POINT            glPolygonOffset
       GL_POLYGON_STIPPLE                 glPolygonStipple
       GL_POST_COLOR_MATRIX_COLOR_TABLE   glColorTable
       GL_POST_CONVOLUTION_COLOR_TABLE    glColorTable
       GL_RESCALE_NORMAL                  glNormal
       GL_SCISSOR_TEST                    glScissor
       GL_SEPARABLE_2D                    glSeparableFilter2D
       GL_STENCIL_TEST                    glStencilFunc, glStencilOp
       GL_TEXTURE_1D                      glTexImage1D
       GL_TEXTURE_2D                      glTexImage2D
       GL_TEXTURE_3D                      glTexImage3D
       GL_TEXTURE_COORD_ARRAY             glTexCoordPointer
       GL_TEXTURE_GEN_Q                   glTexGen
       GL_TEXTURE_GEN_R                   glTexGen
       GL_TEXTURE_GEN_S                   glTexGen
       GL_TEXTURE_GEN_T                   glTexGen
       GL_VERTEX_ARRAY                    glVertexPointer
       ---------------------------------------------------------------------

NOTES

       If an error is generated, glIsEnabled returns 0.

       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 available only  if  the
       GL version is 1.1 or greater

       GL_RESCALE_NORMAL,  and GL_TEXTURE_3D are available only if the GL ver-
       sion is 1.2 or greater.

       GL_COLOR_TABLE,  GL_CONVOLUTION_1D,  GL_CONVOLUTION_2D,   GL_HISTOGRAM,
       GL_MINMAX,                            GL_POST_COLOR_MATRIX_COLOR_TABLE,
       GL_POST_CONVOLUTION_COLOR_TABLE, and GL_SEPARABLE_2D are available only
       if  GL_ARB_imaging is returned when glGet is called with GL_EXTENSIONS.

       When the GL_ARB_multitexture  extension  is  supported,  the  following
       parameters  return  the  associated  value for the active texture unit.
       GL_TEXTURE_1D,          GL_TEXTURE_BINDING_1D,           GL_TEXTURE_2D,
       GL_TEXTURE_BINDING_2D,       GL_TEXTURE_3D,      GL_TEXTURE_BINDING_3D,
       GL_TEXTURE_GEN_S, GL_TEXTURE_GEN_T, GL_TEXTURE_GEN_R, GL_TEXTURE_GEN_Q,
       GL_TEXTURE_MATRIX, and GL_TEXTURE_STACK_DEPTH.  Likewise, the following
       parameters return the associated value for the  active  client  texture
       unit:        GL_TEXTURE_COORD_ARRAY,       GL_TEXTURE_COORD_ARRAY_SIZE,
       GL_TEXTURE_COORD_ARRAY_STRIDE, GL_TEXTURE_COORD_ARRAY_TYPE.

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.

SEE ALSO

       glEnable(3G), glEnableClientState(3G), glGet(3G)

                                                               GLISENABLED(3G)