glEnable, glDisable

C Specification

void glEnable(
    GLenum	 cap)
void glDisable(
    GLenum	 cap)

Parameters

cap

Specifies a symbolic constant indicating a GL capability.

Description

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_PLANEi

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_LIGHTi

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 glEvalCoord1, glEvalMesh1, and glEvalPoint1 generate RGBA values. See glMap1.

GL_MAP1_INDEX

If enabled, calls to glEvalCoord1, glEvalMesh1, and glEvalPoint1 generate color indices. See glMap1.

GL_MAP1_NORMAL

If enabled, calls to glEvalCoord1, glEvalMesh1, and glEvalPoint1 generate normals. See glMap1.

GL_MAP1_TEXTURE_COORD_1

If enabled, calls to glEvalCoord1, glEvalMesh1, and glEvalPoint1 generate s texture coordinates. See glMap1.

GL_MAP1_TEXTURE_COORD_2

If enabled, calls to glEvalCoord1, glEvalMesh1, and glEvalPoint1 generate s and t texture coordinates. See glMap1.

GL_MAP1_TEXTURE_COORD_3

If enabled, calls to glEvalCoord1, glEvalMesh1, and glEvalPoint1 generate s, t, and r texture coordinates. See glMap1.

GL_MAP1_TEXTURE_COORD_4

If enabled, calls to glEvalCoord1, glEvalMesh1, and glEvalPoint1 generate s, t, r, and q texture coordinates. See glMap1.

GL_MAP1_VERTEX_3

If enabled, calls to glEvalCoord1, glEvalMesh1, and glEvalPoint1 generate x, y, and z vertex coordinates. See glMap1.

GL_MAP1_VERTEX_4

If enabled, calls to glEvalCoord1, glEvalMesh1, and glEvalPoint1 generate homogeneous x, y, z, and w vertex coordinates. See glMap1.

GL_MAP2_COLOR_4

If enabled, calls to glEvalCoord2, glEvalMesh2, and glEvalPoint2 generate RGBA values. See glMap2.

GL_MAP2_INDEX

If enabled, calls to glEvalCoord2, glEvalMesh2, and glEvalPoint2 generate color indices. See glMap2.

GL_MAP2_NORMAL

If enabled, calls to glEvalCoord2, glEvalMesh2, and glEvalPoint2 generate normals. See glMap2.

GL_MAP2_TEXTURE_COORD_1

If enabled, calls to glEvalCoord2, glEvalMesh2, and glEvalPoint2 generate s

GL_MAP2_TEXTURE_COORD_2

If enabled, calls to glEvalCoord2, glEvalMesh2, and glEvalPoint2 generate s and t texture coordinates. See glMap2.

GL_MAP2_TEXTURE_COORD_3

If enabled, calls to glEvalCoord2, glEvalMesh2, and glEvalPoint2 generate s, t, and r texture coordinates. See glMap2.

GL_MAP2_TEXTURE_COORD_4

If enabled, calls to glEvalCoord2, glEvalMesh2, and glEvalPoint2 generate s, t, r, and q texture coordinates. See glMap2.

GL_MAP2_VERTEX_3

If enabled, calls to glEvalCoord2, glEvalMesh2, and glEvalPoint2 generate x, y, and z vertex coordinates. See glMap2.

GL_MAP2_VERTEX_4

If enabled, calls to glEvalCoord2, glEvalMesh2, and glEvalPoint2 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_OCCLUSION_TEST_HP

This token enables HP's occlusion-testing extension. If any geometry is rendered while occlusion culling is enabled, and if that geometry would be visible (i.e., rendering it would affect the Z-buffer), the occlusion test state bit is set, indicating that the rendered object is visible. This is typically done to increase performance: if every pixel of a bounding box would be "behind" the current Z-buffer values for those pixels (i.e., the bounding box is entirely occluded), anything you would draw within that bounding box would also be behind the current Z values, and therefore you can cull it (i.e., avoid processing that geometry through the pipeline). Note that this enable has no effect on the current render mode, or any other OpenGL state.

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_RESCALE_NORMAL_EXT

When normal rescaling is enabled, a new operation is added to the transformation of the normal vector into eye coordinates. The normal vector is rescaled after it is multiplied by the inverse modelview matrix and before it is normalized. The rescale factor is chosen so that in many cases normal vectors with unit length in object coordinates will not need to be normalized as they are transformed into eye coordinates.

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_3D_EXT

If supported and enabled, three-dimensional texturing is performed. See glTexImage3DEXT.

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.

Notes

Errors

• 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.

See Also