1 <?xml version=
"1.0" encoding=
"UTF-8"?>
2 <!DOCTYPE book PUBLIC
"-//OASIS//DTD DocBook MathML Module V1.1b1//EN"
3 "http://www.oasis-open.org/docbook/xml/mathml/1.1CR1/dbmathml.dtd">
4 <refentry id=
"glIsEnabled">
9 <holder>Silicon Graphics, Inc.
</holder>
12 <refentrytitle>glIsEnabled
</refentrytitle>
13 <manvolnum>3G
</manvolnum>
16 <refname>glIsEnabled
</refname>
17 <refpurpose>test whether a capability is enabled
</refpurpose>
19 <refsynopsisdiv><title>C Specification
</title>
22 <funcdef>GLboolean
<function>glIsEnabled
</function></funcdef>
23 <paramdef>GLenum
<parameter>cap
</parameter></paramdef>
27 <refsect1 id=
"parameters"><title>Parameters
</title>
30 <term><parameter>cap
</parameter></term>
33 Specifies a symbolic constant indicating a GL capability.
39 <refsect1 id=
"description"><title>Description
</title>
41 <function>glIsEnabled
</function> returns
<constant>GL_TRUE
</constant> if
<parameter>cap
</parameter> is an enabled capability
42 and returns
<constant>GL_FALSE
</constant> otherwise.
43 Initially all capabilities except
<constant>GL_DITHER
</constant> are disabled;
44 <constant>GL_DITHER
</constant> is initially enabled.
47 The following capabilities are accepted for
<parameter>cap
</parameter>:
51 <informaltable frame=
"topbot">
52 <tgroup cols=
"2" align=
"left">
57 <entry rowsep=
"1" align=
"left"><emphasis role=
"bold">
60 <entry rowsep=
"1" align=
"left"><emphasis role=
"bold">
68 <constant>GL_ALPHA_TEST
</constant>
71 <citerefentry><refentrytitle>glAlphaFunc
</refentrytitle></citerefentry>
76 <constant>GL_AUTO_NORMAL
</constant>
79 <citerefentry><refentrytitle>glEvalCoord
</refentrytitle></citerefentry>
84 <constant>GL_BLEND
</constant>
87 <citerefentry><refentrytitle>glBlendFunc
</refentrytitle></citerefentry>,
<citerefentry><refentrytitle>glLogicOp
</refentrytitle></citerefentry>
92 <constant>GL_CLIP_PLANE
</constant><emphasis>i
</emphasis>
95 <citerefentry><refentrytitle>glClipPlane
</refentrytitle></citerefentry>
100 <constant>GL_COLOR_ARRAY
</constant>
103 <citerefentry><refentrytitle>glColorPointer
</refentrytitle></citerefentry>
108 <constant>GL_COLOR_LOGIC_OP
</constant>
111 <citerefentry><refentrytitle>glLogicOp
</refentrytitle></citerefentry>
116 <constant>GL_COLOR_MATERIAL
</constant>
119 <citerefentry><refentrytitle>glColorMaterial
</refentrytitle></citerefentry>
124 <constant>GL_COLOR_SUM
</constant>
127 <citerefentry><refentrytitle>glSecondaryColor
</refentrytitle></citerefentry>
132 <constant>GL_COLOR_TABLE
</constant>
135 <citerefentry><refentrytitle>glColorTable
</refentrytitle></citerefentry>
140 <constant>GL_CONVOLUTION_1D
</constant>
143 <citerefentry><refentrytitle>glConvolutionFilter1D
</refentrytitle></citerefentry>
148 <constant>GL_CONVOLUTION_2D
</constant>
151 <citerefentry><refentrytitle>glConvolutionFilter2D
</refentrytitle></citerefentry>
156 <constant>GL_CULL_FACE
</constant>
159 <citerefentry><refentrytitle>glCullFace
</refentrytitle></citerefentry>
164 <constant>GL_DEPTH_TEST
</constant>
167 <citerefentry><refentrytitle>glDepthFunc
</refentrytitle></citerefentry>,
<citerefentry><refentrytitle>glDepthRange
</refentrytitle></citerefentry>
172 <constant>GL_DITHER
</constant>
175 <citerefentry><refentrytitle>glEnable
</refentrytitle></citerefentry>
180 <constant>GL_EDGE_FLAG_ARRAY
</constant>
183 <citerefentry><refentrytitle>glEdgeFlagPointer
</refentrytitle></citerefentry>
188 <constant>GL_FOG
</constant>
191 <citerefentry><refentrytitle>glFog
</refentrytitle></citerefentry>
196 <constant>GL_FOG_COORD_ARRAY
</constant>
199 <citerefentry><refentrytitle>glFogCoordPointer
</refentrytitle></citerefentry>
204 <constant>GL_HISTOGRAM
</constant>
207 <citerefentry><refentrytitle>glHistogram
</refentrytitle></citerefentry>
212 <constant>GL_INDEX_ARRAY
</constant>
215 <citerefentry><refentrytitle>glIndexPointer
</refentrytitle></citerefentry>
220 <constant>GL_INDEX_LOGIC_OP
</constant>
223 <citerefentry><refentrytitle>glLogicOp
</refentrytitle></citerefentry>
228 <constant>GL_LIGHT
</constant><emphasis>i
</emphasis>
231 <citerefentry><refentrytitle>glLightModel
</refentrytitle></citerefentry>,
<citerefentry><refentrytitle>glLight
</refentrytitle></citerefentry>
236 <constant>GL_LIGHTING
</constant>
239 <citerefentry><refentrytitle>glMaterial
</refentrytitle></citerefentry>,
<citerefentry><refentrytitle>glLightModel
</refentrytitle></citerefentry>,
<citerefentry><refentrytitle>glLight
</refentrytitle></citerefentry>
244 <constant>GL_LINE_SMOOTH
</constant>
247 <citerefentry><refentrytitle>glLineWidth
</refentrytitle></citerefentry>
252 <constant>GL_LINE_STIPPLE
</constant>
255 <citerefentry><refentrytitle>glLineStipple
</refentrytitle></citerefentry>
260 <constant>GL_MAP1_COLOR_4
</constant>
263 <citerefentry><refentrytitle>glMap1
</refentrytitle></citerefentry>
268 <constant>GL_MAP1_INDEX
</constant>
271 <citerefentry><refentrytitle>glMap1
</refentrytitle></citerefentry>
276 <constant>GL_MAP1_NORMAL
</constant>
279 <citerefentry><refentrytitle>glMap1
</refentrytitle></citerefentry>
284 <constant>GL_MAP1_TEXTURE_COORD_1
</constant>
287 <citerefentry><refentrytitle>glMap1
</refentrytitle></citerefentry>
292 <constant>GL_MAP1_TEXTURE_COORD_2
</constant>
295 <citerefentry><refentrytitle>glMap1
</refentrytitle></citerefentry>
300 <constant>GL_MAP1_TEXTURE_COORD_3
</constant>
303 <citerefentry><refentrytitle>glMap1
</refentrytitle></citerefentry>
308 <constant>GL_MAP1_TEXTURE_COORD_4
</constant>
311 <citerefentry><refentrytitle>glMap1
</refentrytitle></citerefentry>
316 <constant>GL_MAP2_COLOR_4
</constant>
319 <citerefentry><refentrytitle>glMap2
</refentrytitle></citerefentry>
324 <constant>GL_MAP2_INDEX
</constant>
327 <citerefentry><refentrytitle>glMap2
</refentrytitle></citerefentry>
332 <constant>GL_MAP2_NORMAL
</constant>
335 <citerefentry><refentrytitle>glMap2
</refentrytitle></citerefentry>
340 <constant>GL_MAP2_TEXTURE_COORD_1
</constant>
343 <citerefentry><refentrytitle>glMap2
</refentrytitle></citerefentry>
348 <constant>GL_MAP2_TEXTURE_COORD_2
</constant>
351 <citerefentry><refentrytitle>glMap2
</refentrytitle></citerefentry>
356 <constant>GL_MAP2_TEXTURE_COORD_3
</constant>
359 <citerefentry><refentrytitle>glMap2
</refentrytitle></citerefentry>
364 <constant>GL_MAP2_TEXTURE_COORD_4
</constant>
367 <citerefentry><refentrytitle>glMap2
</refentrytitle></citerefentry>
372 <constant>GL_MAP2_VERTEX_3
</constant>
375 <citerefentry><refentrytitle>glMap2
</refentrytitle></citerefentry>
380 <constant>GL_MAP2_VERTEX_4
</constant>
383 <citerefentry><refentrytitle>glMap2
</refentrytitle></citerefentry>
388 <constant>GL_MINMAX
</constant>
391 <citerefentry><refentrytitle>glMinmax
</refentrytitle></citerefentry>
396 <constant>GL_MULTISAMPLE
</constant>
399 <citerefentry><refentrytitle>glSampleCoverage
</refentrytitle></citerefentry>
404 <constant>GL_NORMAL_ARRAY
</constant>
407 <citerefentry><refentrytitle>glNormalPointer
</refentrytitle></citerefentry>
412 <constant>GL_NORMALIZE
</constant>
415 <citerefentry><refentrytitle>glNormal
</refentrytitle></citerefentry>
420 <constant>GL_POINT_SMOOTH
</constant>
423 <citerefentry><refentrytitle>glPointSize
</refentrytitle></citerefentry>
428 <constant>GL_POINT_SPRITE
</constant>
431 <citerefentry><refentrytitle>glEnable
</refentrytitle></citerefentry>
436 <constant>GL_POLYGON_SMOOTH
</constant>
439 <citerefentry><refentrytitle>glPolygonMode
</refentrytitle></citerefentry>
444 <constant>GL_POLYGON_OFFSET_FILL
</constant>
447 <citerefentry><refentrytitle>glPolygonOffset
</refentrytitle></citerefentry>
452 <constant>GL_POLYGON_OFFSET_LINE
</constant>
455 <citerefentry><refentrytitle>glPolygonOffset
</refentrytitle></citerefentry>
460 <constant>GL_POLYGON_OFFSET_POINT
</constant>
463 <citerefentry><refentrytitle>glPolygonOffset
</refentrytitle></citerefentry>
468 <constant>GL_POLYGON_STIPPLE
</constant>
471 <citerefentry><refentrytitle>glPolygonStipple
</refentrytitle></citerefentry>
476 <constant>GL_POST_COLOR_MATRIX_COLOR_TABLE
</constant>
479 <citerefentry><refentrytitle>glColorTable
</refentrytitle></citerefentry>
484 <constant>GL_POST_CONVOLUTION_COLOR_TABLE
</constant>
487 <citerefentry><refentrytitle>glColorTable
</refentrytitle></citerefentry>
492 <constant>GL_RESCALE_NORMAL
</constant>
495 <citerefentry><refentrytitle>glNormal
</refentrytitle></citerefentry>
500 <constant>GL_SAMPLE_ALPHA_TO_COVERAGE
</constant>
503 <citerefentry><refentrytitle>glSampleCoverage
</refentrytitle></citerefentry>
508 <constant>GL_SAMPLE_ALPHA_TO_ONE
</constant>
511 <citerefentry><refentrytitle>glSampleCoverage
</refentrytitle></citerefentry>
516 <constant>GL_SAMPLE_COVERAGE
</constant>
519 <citerefentry><refentrytitle>glSampleCoverage
</refentrytitle></citerefentry>
524 <constant>GL_SCISSOR_TEST
</constant>
527 <citerefentry><refentrytitle>glScissor
</refentrytitle></citerefentry>
532 <constant>GL_SECONDARY_COLOR_ARRAY
</constant>
535 <citerefentry><refentrytitle>glSecondaryColorPointer
</refentrytitle></citerefentry>
540 <constant>GL_SEPARABLE_2D
</constant>
543 <citerefentry><refentrytitle>glSeparableFilter2D
</refentrytitle></citerefentry>
548 <constant>GL_STENCIL_TEST
</constant>
551 <citerefentry><refentrytitle>glStencilFunc
</refentrytitle></citerefentry>,
<citerefentry><refentrytitle>glStencilOp
</refentrytitle></citerefentry>
556 <constant>GL_TEXTURE_1D
</constant>
559 <citerefentry><refentrytitle>glTexImage1D
</refentrytitle></citerefentry>
564 <constant>GL_TEXTURE_2D
</constant>
567 <citerefentry><refentrytitle>glTexImage2D
</refentrytitle></citerefentry>
572 <constant>GL_TEXTURE_3D
</constant>
575 <citerefentry><refentrytitle>glTexImage3D
</refentrytitle></citerefentry>
580 <constant>GL_TEXTURE_COORD_ARRAY
</constant>
583 <citerefentry><refentrytitle>glTexCoordPointer
</refentrytitle></citerefentry>
588 <constant>GL_TEXTURE_CUBE_MAP
</constant>
591 <citerefentry><refentrytitle>glTexImage2D
</refentrytitle></citerefentry>
596 <constant>GL_TEXTURE_GEN_Q
</constant>
599 <citerefentry><refentrytitle>glTexGen
</refentrytitle></citerefentry>
604 <constant>GL_TEXTURE_GEN_R
</constant>
607 <citerefentry><refentrytitle>glTexGen
</refentrytitle></citerefentry>
612 <constant>GL_TEXTURE_GEN_S
</constant>
615 <citerefentry><refentrytitle>glTexGen
</refentrytitle></citerefentry>
620 <constant>GL_TEXTURE_GEN_T
</constant>
623 <citerefentry><refentrytitle>glTexGen
</refentrytitle></citerefentry>
628 <constant>GL_VERTEX_ARRAY
</constant>
631 <citerefentry><refentrytitle>glVertexPointer
</refentrytitle></citerefentry>
636 <constant>GL_VERTEX_PROGRAM_POINT_SIZE
</constant>
639 <citerefentry><refentrytitle>glEnable
</refentrytitle></citerefentry>
644 <constant>GL_VERTEX_PROGRAM_TWO_SIDE
</constant>
647 <citerefentry><refentrytitle>glEnable
</refentrytitle></citerefentry>
656 <refsect1 id=
"notes"><title>Notes
</title>
658 If an error is generated,
659 <function>glIsEnabled
</function> returns
0.
662 <constant>GL_COLOR_LOGIC_OP
</constant>,
663 <constant>GL_COLOR_ARRAY
</constant>,
664 <constant>GL_EDGE_FLAG_ARRAY
</constant>,
665 <constant>GL_INDEX_ARRAY
</constant>,
666 <constant>GL_INDEX_LOGIC_OP
</constant>,
667 <constant>GL_NORMAL_ARRAY
</constant>,
668 <constant>GL_POLYGON_OFFSET_FILL
</constant>,
669 <constant>GL_POLYGON_OFFSET_LINE
</constant>,
670 <constant>GL_POLYGON_OFFSET_POINT
</constant>,
671 <constant>GL_TEXTURE_COORD_ARRAY
</constant>, and
672 <constant>GL_VERTEX_ARRAY
</constant>
674 if the GL version is
1.1 or greater.
677 <constant>GL_RESCALE_NORMAL
</constant>, and
<constant>GL_TEXTURE_3D
</constant> are available only if the GL
678 version is
1.2 or greater.
681 <constant>GL_MULTISAMPLE
</constant>,
682 <constant>GL_SAMPLE_ALPHA_TO_COVERAGE
</constant>,
683 <constant>GL_SAMPLE_ALPHA_TO_ONE
</constant>,
684 <constant>GL_SAMPLE_COVERAGE
</constant>,
685 <constant>GL_TEXTURE_CUBE_MAP
</constant>
686 are available only if the GL version is
1.3 or greater.
689 <constant>GL_FOG_COORD_ARRAY
</constant> and
<constant>GL_SECONDARY_COLOR_ARRAY
</constant>
690 are available only if the GL version is
1.4 or greater.
693 <constant>GL_POINT_SPRITE
</constant>,
694 <constant>GL_VERTEX_PROGRAM_POINT_SIZE
</constant>, and
695 <constant>GL_VERTEX_PROGRAM_TWO_SIDE
</constant>
696 are available only if the GL version is
2.0 or greater.
699 <constant>GL_COLOR_TABLE
</constant>,
<constant>GL_CONVOLUTION_1D
</constant>,
<constant>GL_CONVOLUTION_2D
</constant>,
700 <constant>GL_HISTOGRAM
</constant>,
<constant>GL_MINMAX
</constant>,
701 <constant>GL_POST_COLOR_MATRIX_COLOR_TABLE
</constant>,
702 <constant>GL_POST_CONVOLUTION_COLOR_TABLE
</constant>, and
703 <constant>GL_SEPARABLE_2D
</constant> are available only if
<code>ARB_imaging
</code> is
704 returned when
<citerefentry><refentrytitle>glGet
</refentrytitle></citerefentry> is called with
<constant>GL_EXTENSIONS
</constant>.
707 For OpenGL versions
1.3 and greater, or when the
<code>ARB_multitexture
</code> extension is supported, the following
708 parameters return the associated value for the active texture unit:
709 <constant>GL_TEXTURE_1D
</constant>,
710 <constant>GL_TEXTURE_2D
</constant>,
711 <constant>GL_TEXTURE_3D
</constant>,
712 <constant>GL_TEXTURE_CUBE_MAP
</constant>,
713 <constant>GL_TEXTURE_GEN_S
</constant>,
714 <constant>GL_TEXTURE_GEN_T
</constant>,
715 <constant>GL_TEXTURE_GEN_R
</constant>,
716 <constant>GL_TEXTURE_GEN_Q
</constant>,
717 <constant>GL_TEXTURE_MATRIX
</constant>, and
718 <constant>GL_TEXTURE_STACK_DEPTH
</constant>.
719 Likewise, the following parameters return the associated value for the
720 active client texture unit:
721 <constant>GL_TEXTURE_COORD_ARRAY
</constant>,
722 <constant>GL_TEXTURE_COORD_ARRAY_SIZE
</constant>,
723 <constant>GL_TEXTURE_COORD_ARRAY_STRIDE
</constant>,
724 <constant>GL_TEXTURE_COORD_ARRAY_TYPE
</constant>.
727 <refsect1 id=
"errors"><title>Errors
</title>
729 <constant>GL_INVALID_ENUM
</constant> is generated if
<parameter>cap
</parameter> is not an accepted value.
732 <constant>GL_INVALID_OPERATION
</constant> is generated if
<function>glIsEnabled
</function>
733 is executed between the execution of
<citerefentry><refentrytitle>glBegin
</refentrytitle></citerefentry>
734 and the corresponding execution of
<citerefentry><refentrytitle>glEnd
</refentrytitle></citerefentry>.
737 <refsect1 id=
"seealso"><title>See Also
</title>
739 <citerefentry><refentrytitle>glEnable
</refentrytitle></citerefentry>,
740 <citerefentry><refentrytitle>glEnableClientState
</refentrytitle></citerefentry>,
741 <citerefentry><refentrytitle>glGet
</refentrytitle></citerefentry>
744 <refsect1 id=
"Copyright"><title>Copyright
</title>
746 Copyright
<trademark class=
"copyright"></trademark> 1991-
2006
747 Silicon Graphics, Inc. This document is licensed under the SGI
748 Free Software B License. For details, see
749 <ulink url=
"http://oss.sgi.com/projects/FreeB/">http://oss.sgi.com/projects/FreeB/
</ulink>.