GLENABLE(3G)

📦 version 24.3.3, in opensuse-leap 16.0

💅 glEnable / glDisable — enable or disable server-side GL capabilities 💅

okay bestie, welcome to the GLENABLE(3G) page — it’s literally the on/off switch situation for server-side GL capabilities, and yes it ate. 🫶

🌸 NAME 🌸

glEnable, glDisable — enable or disable server-side GL capabilities. that’s the whole title, no cap.

✨ C SPECIFICATION ✨

void glEnable( GLenum cap )

🎀 PARAMETERS 🎀

  • cap — a symbolic constant that tells the function which GL capability you mean. cute, symbolic, iconic.

✨ C SPECIFICATION ✨

void glDisable( GLenum cap )

🎀 PARAMETERS 🎀

  • cap — same deal: a symbolic constant that names a GL capability.

💖 DESCRIPTION 💖

okay so glEnable and glDisable are the duo that enable and disable various capabilities. If you need to know the current setting of any capability, use glIsEnabled or glGet — that’s your vibe check. The initial value for each capability is GL_FALSE, with one exception: GL_DITHER starts out as GL_TRUE. Not me pointing out the one exception, but here we are. 😭

Both glEnable and glDisable take a single argument, cap, and it can assume one of these iconic 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_COLOR_TABLE — if enabled, do a color table lookup on the incoming RGBA color values. See glColorTable.
  • GL_CONVOLUTION_1D — if enabled, perform a 1D convolution operation on incoming RGBA color values. See glConvolutionFilter1D.
  • GL_CONVOLUTION_2D — if enabled, perform a 2D convolution operation on incoming RGBA color values. See glConvolutionFilter2D.
  • 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. big caveat: 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_HISTOGRAM — if enabled, histogram incoming RGBA color values. See glHistogram.
  • 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 texture coordinates. See glMap2.
  • 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_MINMAX — if enabled, compute the minimum and maximum values of incoming RGBA color values. See glMinmax.
  • 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_POST_COLOR_MATRIX_COLOR_TABLE — if enabled, do a color table lookup on RGBA color values after color matrix transformation. See glColorTable.
  • GL_POST_CONVOLUTION_COLOR_TABLE — if enabled, do a color table lookup on RGBA color values after convolution. See glColorTable.
  • GL_RESCALE_NORMAL — if enabled, normal vectors specified with glNormal are scaled to unit length after transformation. See glNormal.
  • GL_SEPARABLE_2D — if enabled, perform a two-dimensional convolution operation using a separable convolution filter on incoming RGBA color values. See glSeparableFilter2D.
  • 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 — turn this on and you get one-dimensional texturing, bestie ✨ (unless two- or three-dimensional texturing is also on, which, like, rude to this one but okay). See glTexImage1D.
  • GL_TEXTURE_2D — enables two-dimensional texturing, gorgeous 💅 (again, she yields if three-dimensional texturing is also enabled). See glTexImage2D.
  • GL_TEXTURE_3D — three-dimensional texturing time, no competition here, she's the main character 👑. See glTexImage3D.
  • GL_TEXTURE_GEN_Q — when this is on, the q texture coordinate gets computed by the texture generation function you set up with glTexGen. When it's off? You just use the current q texture coordinate, simple as that 💖. See glTexGen.
  • GL_TEXTURE_GEN_R — same vibe as above but for the r coordinate: enabled means it's computed via the texture generation function from glTexGen, otherwise the current r texture coordinate is used. See glTexGen.
  • GL_TEXTURE_GEN_S — the s coordinate version of the whole situation: enabled = computed with the glTexGen function, otherwise the current s texture coordinate is what you get 🎀. See glTexGen.
  • GL_TEXTURE_GEN_T — and finally the t coordinate: enabled = computed using the generation function from glTexGen, otherwise the current t texture coordinate. See glTexGen.

💫 NOTES 💫

Okay so some of these have a vibe check attached, meaning they only exist on newer GL, lowkey important 🫶:

  • GL_POLYGON_OFFSET_FILL, GL_POLYGON_OFFSET_LINE, GL_POLYGON_OFFSET_POINT, GL_COLOR_LOGIC_OP, and GL_INDEX_LOGIC_OP? Only available if the GL version is 1.1 or greater, periodt.
  • GL_RESCALE_NORMAL and GL_TEXTURE_3D? Only available if the GL version is 1.2 or greater 🦋.
  • GL_COLOR_TABLE, GL_CONVOLUTION_1D, GL_CONVOLUTION_2D, GL_HISTOGRAM, GL_MINMAX, GL_POST_COLOR_MATRIX_COLOR_TABLE, GL_POST_CONVOLUTION_COLOR_TABLE, and GL_SEPARABLE_2D? These are available only if GL_ARB_imaging is returned from glGet with an argument of GL_EXTENSIONS — like, check the extension list first, iykyk 👀.
  • And here's a big one 🔥: if GL_ARB_multitexture is supported, then GL_TEXTURE_1D, GL_TEXTURE_2D, GL_TEXTURE_3D, GL_TEXTURE_GEN_S, GL_TEXTURE_GEN_T, GL_TEXTURE_GEN_R, and GL_TEXTURE_GEN_Q enable or disable the respective state for the active texture unit specified with glActiveTextureARB. So like, whichever unit you picked, that's the one getting the toggle 💅.

💀 ERRORS 💀

  • GL_INVALID_ENUM gets generated if cap is not one of the values listed previously. So don't be making up caps, bestie, she will know 🙈.
  • GL_INVALID_OPERATION gets generated if glEnable or glDisable is executed between the execution of glBegin and the corresponding execution of glEnd. Like, do not do that mid-primitive, it's giving undefined-chaos energy 😭.

🌈 SEE ALSO 🌈

The whole friend group, assembled 🫶:

glActiveTextureARB(3G), glAlphaFunc(3G), glBlendFunc(3G), glClipPlane(3G), glColorMaterial(3G), glCullFace(3G), glDepthFunc(3G), glDepthRange(3G), glEnableClientState(3G), glFog(3G), glGet(3G), glIsEnabled(3G), glLight(3G), glLightModel(3G), glLineWidth(3G), glLineStipple(3G), glLogicOp(3G), glMap1(3G), glMap2(3G), glMaterial(3G), glNormal(3G), glPointSize(3G), glPolygonMode(3G), glPolygonOffset(3G), glPolygonStipple(3G), glScissor(3G), glStencilFunc(3G), glStencilOp(3G), glTexGen(3G), glTexImage1D(3G), glTexImage2D(3G), glTexImage3D(3G)

That's the whole page, bestie — go forth and enable things responsibly 🌸 And that little footer at the bottom? It's GLENABLE(3G), the source/version tag doing its quiet iconic thing. Byeee 💜🦋

📦 where this page comes from