glIsEnabled -	test whether a capability is enabled

glIsEnabled
	glIsEnabled(cap) -> None

GLboolean glIsEnabled( GLenum	cap )

cap  Specifies a symbolic constant indicating	a GL
     capability.

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_CULL_FACE		     glCullFace
GL_DEPTH_TEST		     glDepthFunc, glDepthRange
GL_DITHER		     glEnable
GL_EDGE_FLAG_ARRAY	     glEdgeFlagPointer
GL_FOG		     glFog
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, 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_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_SCISSOR_TEST	     glScissor
GL_STENCIL_TEST	     glStencilFunc, glStencilOp
GL_TEXTURE_1D		     glTexImage1D
GL_TEXTURE_2D		     glTexImage2D
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

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 only available if	the GL version is 1.1
or greater

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.

glEnable, glEnableClientState