| Extracted from Pike v7.8 release 866 at 2018-07-18.

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GL

# Method GL.glEnable()

Method glEnable

  `void glEnable(int cap)`

Description

  glEnable and glDisable enable and disable various capabilities. Use glIsEnabled or glGet to determine the current setting of any capability. The initial value for each capability with the exception of GL_DITHER is GL_FALSE . The initial value for GL_DITHER is GL_TRUE .

  Both glEnable and glDisable take a single argument, cap, which can assume one of the following values:

  GL_ALPHA_TEST | If enabled, do alpha testing. See glAlphaFunc .
  GL_AUTO_NORMAL | If enabled, generate normal vectors when either GL_MAP2_VERTEX_3 or GL_MAP2_VERTEX_4 is used to generate vertices. See glMap2 .
  GL_BLEND | If enabled, blend the incoming RGBA color values with the values in the color buffers. See glBlendFunc .
  GL_CLIP_PLANE i | If enabled, clip geometry against user-defined clipping plane i. See glClipPlane .
  GL_COLOR_LOGIC_OP | If enabled, apply the currently selected logical operation to the incoming RGBA color and color buffer values. See glLogicOp .
  GL_COLOR_MATERIAL | If enabled, have one or more material parameters track the current color. See glColorMaterial .
  GL_CULL_FACE | If enabled, cull polygons based on their winding in window coordinates. See glCullFace .
  GL_DEPTH_TEST | 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 glDepthFunc and glDepthRange .
  GL_DITHER | If enabled, dither color components or indices before they are written to the color buffer.
  GL_FOG | If enabled, blend a fog color into the posttexturing color. See glFog .
  GL_INDEX_LOGIC_OP | If enabled, apply the currently selected logical operation to the incoming index and color buffer indices. See glLogicOp .
  GL_LIGHT i | If enabled, include light i in the evaluation of the lighting equation. See glLightModel and glLight .
  GL_LIGHTING | 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 glMaterial , glLightModel , and glLight .
  GL_LINE_SMOOTH | If enabled, draw lines with correct filtering. Otherwise, draw aliased lines. See glLineWidth .
  GL_LINE_STIPPLE | If enabled, use the current line stipple pattern when drawing lines. See glLineStipple .
  GL_MAP1_COLOR_4 | If enabled, calls to glEvalCoord , glEvalMesh1 , and glEvalPoint generate RGBA values. See glMap1 .
  GL_MAP1_INDEX | If enabled, calls to glEvalCoord , glEvalMesh1 , and glEvalPoint generate color indices. See glMap1 .
  GL_MAP1_NORMAL | If enabled, calls to glEvalCoord , glEvalMesh1 , and glEvalPoint generate normals. See glMap1 .
  GL_MAP1_TEXTURE_COORD_1 | If enabled, calls to glEvalCoord , glEvalMesh1 , and glEvalPoint generate s texture coordinates. See glMap1 .
  GL_MAP1_TEXTURE_COORD_2 | If enabled, calls to glEvalCoord , glEvalMesh1 , and glEvalPoint generate s and t texture coordinates. See glMap1 .
  GL_MAP1_TEXTURE_COORD_3 | If enabled, calls to glEvalCoord , glEvalMesh1 , and glEvalPoint generate s, t, and r texture coordinates. See glMap1 .
  GL_MAP1_TEXTURE_COORD_4 | If enabled, calls to glEvalCoord , glEvalMesh1 , and glEvalPoint generate s, t, r, and q texture coordinates. See glMap1 .
  GL_MAP1_VERTEX_3 | If enabled, calls to glEvalCoord , glEvalMesh1 , and glEvalPoint generate x, y, and z vertex coordinates. See glMap1 .
  GL_MAP1_VERTEX_4 | If enabled, calls to glEvalCoord , glEvalMesh1 , and glEvalPoint generate homogeneous x, y, z, and w vertex coordinates. See glMap1 .
  GL_MAP2_COLOR_4 | If enabled, calls to glEvalCoord , glEvalMesh2 , and glEvalPoint generate RGBA values. See glMap2 .
  GL_MAP2_INDEX | If enabled, calls to glEvalCoord , glEvalMesh2 , and glEvalPoint generate color indices. See glMap2 .
  GL_MAP2_NORMAL | If enabled, calls to glEvalCoord , glEvalMesh2 , and glEvalPoint generate normals. See glMap2 .
  GL_MAP2_TEXTURE_COORD_1 | If enabled, calls to glEvalCoord , glEvalMesh2 , and glEvalPoint generate s texture coordinates. See glMap2 .
  GL_MAP2_TEXTURE_COORD_2 | If enabled, calls to glEvalCoord , glEvalMesh2 , and glEvalPoint generate s and t texture coordinates. See glMap2 .
  GL_MAP2_TEXTURE_COORD_3 | If enabled, calls to glEvalCoord , glEvalMesh2 , and glEvalPoint generate s, t, and r texture coordinates. See glMap2 .
  GL_MAP2_TEXTURE_COORD_4 | If enabled, calls to glEvalCoord , glEvalMesh2 , and glEvalPoint generate s, t, r, and q texture coordinates. See glMap2 .
  GL_MAP2_VERTEX_3 | If enabled, calls to glEvalCoord , glEvalMesh2 , and glEvalPoint generate x, y, and z vertex coordinates. See glMap2 .
  GL_MAP2_VERTEX_4 | If enabled, calls to glEvalCoord , glEvalMesh2 , and glEvalPoint generate homogeneous x, y, z, and w vertex coordinates. See glMap2 .
  GL_NORMALIZE | If enabled, normal vectors specified with glNormal are scaled to unit length after transformation. See glNormal .
  GL_POINT_SMOOTH | If enabled, draw points with proper filtering. Otherwise, draw aliased points. See glPointSize .
  GL_POLYGON_OFFSET_FILL | If enabled, and if the polygon is rendered in GL_FILL mode, an offset is added to depth values of a polygon's fragments before the depth comparison is performed. See glPolygonOffset .
  GL_POLYGON_OFFSET_LINE | If enabled, and if the polygon is rendered in GL_LINE mode, an offset is added to depth values of a polygon's fragments before the depth comparison is performed. See glPolygonOffset .
  GL_POLYGON_OFFSET_POINT | 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 GL_POINT mode. See glPolygonOffset .
  GL_POLYGON_SMOOTH | 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.
  GL_POLYGON_STIPPLE | If enabled, use the current polygon stipple pattern when rendering polygons. See glPolygonStipple .
  GL_SCISSOR_TEST | If enabled, discard fragments that are outside the scissor rectangle. See glScissor .
  GL_STENCIL_TEST | If enabled, do stencil testing and update the stencil buffer. See glStencilFunc and glStencilOp .
  GL_TEXTURE_1D | If enabled, one-dimensional texturing is performed (unless two-dimensional texturing is also enabled). See glTexImage1D .
  GL_TEXTURE_2D | If enabled, two-dimensional texturing is performed. See glTexImage2D .
  GL_TEXTURE_GEN_Q | If enabled, the q texture coordinate is computed using the texture generation function defined with glTexGen . Otherwise, the current q texture coordinate is used. See glTexGen .
  GL_TEXTURE_GEN_R | If enabled, the r texture coordinate is computed using the texture generation function defined with glTexGen . Otherwise, the current r texture coordinate is used. See glTexGen .
  GL_TEXTURE_GEN_S | If enabled, the s texture coordinate is computed using the texture generation function defined with glTexGen . Otherwise, the current s texture coordinate is used. See glTexGen .
  GL_TEXTURE_GEN_T | If enabled, the t texture coordinate is computed using the texture generation function defined with glTexGen . Otherwise, the current t texture coordinate is used. See glTexGen .

Parameter `cap`

  Specifies a symbolic constant indicating a GL capability.

Parameter `cap`

  Specifies a symbolic constant indicating a GL capability.

Throws

  GL_INVALID_ENUM is generated if cap is not one of the values listed previously.

  GL_INVALID_OPERATION is generated if glEnable or glDisable is executed between the execution of glBegin and the corresponding execution of glEnd .