'\"! eqn|tbl | mmdoc
'\"macro stdmacro
.ds Vn Version 1.2
.ds Dt 6 March 1997
.ds Re Release 1.1.0
.ds Dp Mar 17 18:04
.ds Dm  Mar  6 20:0
.ds Xs 2523 20 enable.gl
.TH GLENABLE
.SH NAME
.B "glEnable, glDisable
\- enable or disable server-side GL capabilities

.SH C SPECIFICATION
void \f3glEnable\fP(
GLenum \fIcap\fP )
.nf
.fi

.SH PARAMETERS
.TP \w'\f2cap\fP\ \ 'u 
\f2cap\fP
Specifies a symbolic constant indicating a GL capability.
.SH C SPECIFICATION
void \f3glDisable\fP(
GLenum \fIcap\fP )
.nf
.fi

.SH PARAMETERS
.TP
\f2cap\fP
Specifies a symbolic constant indicating a GL capability.
.SH DESCRIPTION
\f3glEnable\fP and \f3glDisable\fP enable and disable various capabilities.
Use \f3glIsEnabled\fP or \f3glGet\fP to determine the current setting
of any capability. The initial value for each capability with the
exception of \f3GL_DITHER\fP is \f3GL_FALSE\fP. The initial value for
\f3GL_DITHER\fP is \f3GL_TRUE\fP. 
.P
Both \f3glEnable\fP and \f3glDisable\fP take a single argument, \f2cap\fP,
which can assume one of the following values:
.TP 25
\f3GL_ALPHA_TEST\fP
If enabled,
do alpha testing. See
\f3glAlphaFunc\fP.
.TP
\f3GL_AUTO_NORMAL\fP
If enabled,
generate normal vectors when either
\f3GL_MAP2_VERTEX_3\fP or
\f3GL_MAP2_VERTEX_4\fP is used to generate vertices. 
See \f3glMap2\fP.
.TP
\f3GL_BLEND\fP
If enabled,
blend the incoming RGBA color values with the values in the color
buffers. See \f3glBlendFunc\fP.
.TP
\f3GL_CLIP_PLANE\fP\f2i\fP
If enabled,
clip geometry against user-defined clipping plane \f2i\fP.
See \f3glClipPlane\fP.
.TP
\f3GL_COLOR_LOGIC_OP\fP
If enabled,
apply the currently selected logical operation to the incoming RGBA
color and color buffer values. See \f3glLogicOp\fP.
.TP
\f3GL_COLOR_MATERIAL\fP
If enabled,
have one or more material parameters track the current color.
See \f3glColorMaterial\fP.
.TP
\f3GL_CULL_FACE\fP
If enabled,
cull polygons based on their winding in window coordinates. 
See \f3glCullFace\fP.
.TP
\f3GL_DEPTH_TEST\fP
If enabled,
do depth comparisons and update the depth buffer. Note that even if
the depth buffer exists and the depth mask is non-zero, the 
depth buffer is not updated if the depth test is disabled. See
\f3glDepthFunc\fP and 
.br
\f3glDepthRange\fP. 
.TP
\f3GL_DITHER\fP	
If enabled,
dither color components or indices before they are written to the
color buffer.
.TP
\f3GL_FOG\fP
If enabled,
blend a fog color into the posttexturing color.
See \f3glFog\fP.
.TP
\f3GL_INDEX_LOGIC_OP\fP
If enabled,
apply the currently selected logical operation to the incoming index and color
buffer indices. See 
.br
\f3glLogicOp\fP.
.TP
\f3GL_LIGHT\fP\f2i\fP
If enabled,
include light \f2i\fP in the evaluation of the lighting
equation. See \f3glLightModel\fP and \f3glLight\fP.
.TP
\f3GL_LIGHTING\fP
If enabled,
use the current lighting parameters to compute the vertex color or index.
Otherwise, simply associate the current color or index with each
vertex. See 
.br
\f3glMaterial\fP, \f3glLightModel\fP, and \f3glLight\fP.
.TP
\f3GL_LINE_SMOOTH\fP
If enabled,
draw lines with correct filtering.
Otherwise,
draw aliased lines.
See \f3glLineWidth\fP.
.TP
\f3GL_LINE_STIPPLE\fP
If enabled,
use the current line stipple pattern when drawing lines. See
\f3glLineStipple\fP. 
.TP
\f3GL_MAP1_COLOR_4\fP
If enabled,
calls to
\f3glEvalCoord1\fP,
\f3glEvalMesh1\fP, and
\f3glEvalPoint1\fP generate RGBA values.
See \f3glMap1\fP.
.TP
\f3GL_MAP1_INDEX\fP
If enabled,
calls to
\f3glEvalCoord1\fP,
\f3glEvalMesh1\fP, and
\f3glEvalPoint1\fP generate color indices.
See \f3glMap1\fP.
.TP
\f3GL_MAP1_NORMAL\fP
If enabled,
calls to
\f3glEvalCoord1\fP,
\f3glEvalMesh1\fP, and
\f3glEvalPoint1\fP generate normals.
See \f3glMap1\fP.
.TP
\f3GL_MAP1_TEXTURE_COORD_1\fP
If enabled,
calls to
\f3glEvalCoord1\fP,
\f3glEvalMesh1\fP, and
\f3glEvalPoint1\fP generate
\f2s\fP
texture coordinates.
See \f3glMap1\fP.
.TP
\f3GL_MAP1_TEXTURE_COORD_2\fP
If enabled,
calls to
\f3glEvalCoord1\fP,
\f3glEvalMesh1\fP, and
\f3glEvalPoint1\fP generate
\f2s\fP and
\f2t\fP texture coordinates.
See \f3glMap1\fP.
.TP
\f3GL_MAP1_TEXTURE_COORD_3\fP
If enabled,
calls to
\f3glEvalCoord1\fP,
\f3glEvalMesh1\fP, and
\f3glEvalPoint1\fP generate
\f2s\fP,
\f2t\fP, and
\f2r\fP texture coordinates.
See \f3glMap1\fP.
.TP
\f3GL_MAP1_TEXTURE_COORD_4\fP
If enabled,
calls to
\f3glEvalCoord1\fP,
\f3glEvalMesh1\fP, and
\f3glEvalPoint1\fP generate
\f2s\fP,
\f2t\fP,
\f2r\fP, and
\f2q\fP texture coordinates.
See \f3glMap1\fP.
.TP
\f3GL_MAP1_VERTEX_3\fP
If enabled,
calls to
\f3glEvalCoord1\fP,
\f3glEvalMesh1\fP, and
\f3glEvalPoint1\fP generate
\f2x\fP, \f2y\fP, and \f2z\fP vertex coordinates.
See \f3glMap1\fP.
.TP
\f3GL_MAP1_VERTEX_4\fP
If enabled,
calls to
\f3glEvalCoord1\fP,
\f3glEvalMesh1\fP, and
\f3glEvalPoint1\fP generate
homogeneous
\f2x\fP,
\f2y\fP,
\f2z\fP, and
\f2w\fP vertex coordinates.
See \f3glMap1\fP.
.TP
\f3GL_MAP2_COLOR_4\fP
If enabled,
calls to
\f3glEvalCoord2\fP,
\f3glEvalMesh2\fP, and
\f3glEvalPoint2\fP generate RGBA values.
See \f3glMap2\fP.
.TP
\f3GL_MAP2_INDEX\fP
If enabled,
calls to
\f3glEvalCoord2\fP,
\f3glEvalMesh2\fP, and
\f3glEvalPoint2\fP generate color indices.
See \f3glMap2\fP.
.TP
\f3GL_MAP2_NORMAL\fP
If enabled,
calls to
\f3glEvalCoord2\fP,
\f3glEvalMesh2\fP, and
\f3glEvalPoint2\fP generate normals.
See \f3glMap2\fP.
.TP
\f3GL_MAP2_TEXTURE_COORD_1\fP
If enabled,
calls to
\f3glEvalCoord2\fP,
\f3glEvalMesh2\fP, and
\f3glEvalPoint2\fP generate
\f2s\fP
texture coordinates.
See \f3glMap2\fP.
.TP
\f3GL_MAP2_TEXTURE_COORD_2\fP
If enabled,
calls to
\f3glEvalCoord2\fP,
\f3glEvalMesh2\fP, and
\f3glEvalPoint2\fP generate
\f2s\fP and
\f2t\fP texture coordinates.
See \f3glMap2\fP.
.TP
\f3GL_MAP2_TEXTURE_COORD_3\fP
If enabled,
calls to
\f3glEvalCoord2\fP,
\f3glEvalMesh2\fP, and
\f3glEvalPoint2\fP generate
\f2s\fP,
\f2t\fP, and
\f2r\fP texture coordinates.
See \f3glMap2\fP.
.TP
\f3GL_MAP2_TEXTURE_COORD_4\fP
If enabled,
calls to
\f3glEvalCoord2\fP,
\f3glEvalMesh2\fP, and
\f3glEvalPoint2\fP generate
\f2s\fP,
\f2t\fP,
\f2r\fP, and
\f2q\fP texture coordinates.
See \f3glMap2\fP.
.TP
\f3GL_MAP2_VERTEX_3\fP
If enabled,
calls to
\f3glEvalCoord2\fP,
\f3glEvalMesh2\fP, and
\f3glEvalPoint2\fP generate
\f2x\fP, \f2y\fP, and \f2z\fP vertex coordinates.
See \f3glMap2\fP.
.TP
\f3GL_MAP2_VERTEX_4\fP
If enabled,
calls to
\f3glEvalCoord2\fP,
\f3glEvalMesh2\fP, and
\f3glEvalPoint2\fP generate
homogeneous
\f2x\fP,
\f2y\fP,
\f2z\fP, and
\f2w\fP vertex coordinates.
See \f3glMap2\fP.
.TP
\f3GL_NORMALIZE\fP
If enabled,
normal vectors specified with \f3glNormal\fP are scaled to unit length
after transformation. See \f3glNormal\fP.
.TP
\f3GL_POINT_SMOOTH\fP
If enabled,
draw points with proper filtering.
Otherwise,
draw aliased points.
See \f3glPointSize\fP.
.TP
\f3GL_POLYGON_OFFSET_FILL\fP
If enabled, and if the polygon is rendered in
\f3GL_FILL\fP mode, an offset is added to depth values of a polygon's
fragments before the depth comparison is performed. See
\f3glPolygonOffset\fP. 
.TP
\f3GL_POLYGON_OFFSET_LINE\fP
If enabled, and if the polygon is rendered in
\f3GL_LINE\fP mode, an offset is added to depth values of a polygon's
fragments before the depth comparison is performed. See \f3glPolygonOffset\fP. 
.TP
\f3GL_POLYGON_OFFSET_POINT\fP
If enabled, an offset is added to depth values of a polygon's fragments
before the depth comparison is performed, if the polygon is rendered in 
\f3GL_POINT\fP mode. See 
.br
\f3glPolygonOffset\fP. 
.TP
\f3GL_POLYGON_SMOOTH\fP
If enabled, draw polygons with proper filtering.
Otherwise, draw aliased polygons. For correct anti-aliased polygons,
an alpha buffer is needed and the polygons must be sorted front to
back. 
.TP
\f3GL_POLYGON_STIPPLE\fP
If enabled,
use the current polygon stipple pattern when rendering
polygons. See \f3glPolygonStipple\fP.
.TP
\f3GL_SCISSOR_TEST\fP
If enabled,
discard fragments that are outside the scissor rectangle. 
See \f3glScissor\fP.
.TP
\f3GL_STENCIL_TEST\fP
If enabled,
do stencil testing and update the stencil buffer. 
See \f3glStencilFunc\fP and \f3glStencilOp\fP.
.TP
\f3GL_TEXTURE_1D\fP
If enabled,
one-dimensional texturing is performed
(unless two-dimensional texturing is also enabled). See \f3glTexImage1D\fP.
.TP
\f3GL_TEXTURE_2D\fP
If enabled,
two-dimensional texturing is performed. See \f3glTexImage2D\fP.
.TP
\f3GL_TEXTURE_GEN_Q\fP
If enabled,
the \f2q\fP texture coordinate is computed using
the texture generation function defined with \f3glTexGen\fP.
Otherwise, the current \f2q\fP texture coordinate is used.
See \f3glTexGen\fP.
.TP
\f3GL_TEXTURE_GEN_R\fP
If enabled,
the \f2r\fP texture coordinate is computed using
the texture generation function defined with \f3glTexGen\fP.
Otherwise, the current \f2r\fP texture coordinate is used.
See \f3glTexGen\fP.
.TP
\f3GL_TEXTURE_GEN_S\fP
If enabled,
the \f2s\fP texture coordinate is computed using
the texture generation function defined with \f3glTexGen\fP.
Otherwise, the current \f2s\fP texture coordinate is used. 
See \f3glTexGen\fP.
.TP
\f3GL_TEXTURE_GEN_T\fP
If enabled,
the \f2t\fP texture coordinate is computed using
the texture generation function defined with \f3glTexGen\fP.
Otherwise, the current \f2t\fP texture coordinate is used.
See \f3glTexGen\fP.
.SH NOTES
\f3GL_POLYGON_OFFSET_FILL\fP, \f3GL_POLYGON_OFFSET_LINE\fP,
\f3GL_POLYGON_OFFSET_POINT\fP,
\f3GL_COLOR_LOGIC_OP\fP, and \f3GL_INDEX_LOGIC_OP\fP are only available
if the GL version is 1.1 or greater. 
.SH ERRORS
\f3GL_INVALID_ENUM\fP is generated if \f2cap\fP is not one of the values
listed previously.
.P
\f3GL_INVALID_OPERATION\fP is generated if \f3glEnable\fP or \f3glDisable\fP
is executed between the execution of \f3glBegin\fP
and the corresponding execution of \f3glEnd\fP.
.SH SEE ALSO
\f3glAlphaFunc\fP,
\f3glBlendFunc\fP,
\f3glClipPlane\fP,
\f3glColorMaterial\fP,
\f3glCullFace\fP,
.br
\f3glDepthFunc\fP,
\f3glDepthRange\fP,
\f3glEnableClientState\fP,
\f3glFog\fP,
\f3glGet\fP,
\f3glIsEnabled\fP,
\f3glLight\fP,
\f3glLightModel\fP,
\f3glLineWidth\fP,
\f3glLineStipple\fP,
\f3glLogicOp\fP,
\f3glMap1\fP,
\f3glMap2\fP,
\f3glMaterial\fP,
\f3glNormal\fP,
\f3glPointSize\fP,
\f3glPolygonMode\fP,
\f3glPolygonOffset\fP,
.br
\f3glPolygonStipple\fP,
\f3glScissor\fP,
\f3glStencilFunc\fP,
\f3glStencilOp\fP,
\f3glTexGen\fP,
\f3glTexImage1D\fP,
\f3glTexImage2D\fP