glEnable — enable or disable server-side GL capabilities
void glEnable(
|
GLenum cap) ; |
void glDisable(
|
GLenum cap) ; |
void glEnablei(
|
GLenum cap, |
GLuint index) ; |
void glDisablei(
|
GLenum cap, |
GLuint index) ; |
cap
Specifies a symbolic constant indicating a GL capability.
index
Specifies the index of the switch to disable (for
glEnablei
and
glDisablei
only).
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:
Some of the GL's capabilities are indexed. glEnablei
and glDisablei
enable and disable
indexed capabilities.
GL_BLEND
If enabled, blend the computed fragment color values with the values in the color buffers. See glBlendFunc.
GL_CULL_FACE
If enabled, cull polygons based on their winding in window coordinates. See glCullFace.
GL_DEBUG_OUTPUT
If enabled, debug messages are produced by a debug context. When disabled,
the debug message log is silenced. Note that in a non-debug context, very
few, if any messages might be produced, even when GL_DEBUG_OUTPUT
is enabled.
GL_DEBUG_OUTPUT_SYNCHRONOUS
If enabled, debug messages are produced synchronously by a debug context. If disabled, debug messages may be produced asynchronously. In particular, they may be delayed relative to the execution of GL commands, and the debug callback function may be called from a thread other than that in which the commands are executed. See glDebugMessageCallback.
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 glDepthRangef.
GL_DITHER
If enabled, dither color components or indices before they are written to the color buffer.
GL_POLYGON_OFFSET_FILL
If enabled, an offset is added to depth values of a polygon's fragments before the depth comparison is performed. See glPolygonOffset.
GL_PRIMITIVE_RESTART_FIXED_INDEX
Enables primitive restarting. If enabled, any one of the draw commands
which transfers a set of generic attribute array elements to the GL will restart
the primitive when the index of the vertex is equal to
where n is 8, 16 or 32 if the type is
GL_UNSIGNED_BYTE
,
GL_UNSIGNED_SHORT
, or
GL_UNSIGNED_INT
, respectively.
GL_RASTERIZER_DISCARD
If enabled, primitives are discarded immediately before the rasterization stage, but after the optional transform feedback stage. glClear and glClearBuffer* commands are also ignored.
GL_SAMPLE_ALPHA_TO_COVERAGE
If enabled, compute a temporary coverage value where each bit is determined by the alpha value at the corresponding sample location. The temporary coverage value is then ANDed with the fragment coverage value.
GL_SAMPLE_COVERAGE
If enabled,
the fragment's coverage is ANDed with the temporary coverage value. If
GL_SAMPLE_COVERAGE_INVERT
is set to GL_TRUE
, invert the coverage
value.
See glSampleCoverage.
GL_SAMPLE_MASK
If enabled, the fragment's coverage is ANDed with the coverage value GL_SAMPLE_MASK_VALUE
.
See glSampleMaski.
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_INVALID_ENUM
is generated if cap
is not one of the values
listed previously.
GL_INVALID_VALUE
is generated by glEnablei
and glDisablei
if index
is greater than or equal to the number of indexed capabilities for cap
.
Any token accepted by glEnable
or glDisable
is also accepted by
glEnablei
and glDisablei
, but if the capability is not indexed,
the maximum value that index
may take is zero.
In general, passing an indexed capability to glEnable
or glDisable
will enable or disable that capability for all indices, respectively.
OpenGL ES API Version | ||||
---|---|---|---|---|
Function Name | 2.0 | 3.0 | 3.1 | 3.2 |
glEnable
|
✔ | ✔ | ✔ | ✔ |
glDisable
|
✔ | ✔ | ✔ | ✔ |
glEnablei
|
- | - | - | ✔ |
glDisablei
|
- | - | - | ✔ |
glBlendFunc, glCullFace, glDepthFunc, glDepthRangef, glGet, glIsEnabled, glPolygonOffset, glSampleCoverage, glScissor, glStencilFunc, glStencilOp,
Copyright © 1991-2006 Silicon Graphics, Inc. Copyright © 2010-2015 Khronos Group. This document is licensed under the SGI Free Software B License. For details, see https://khronos.org/registry/OpenGL-Refpages/LICENSES/LicenseRef-FreeB.txt.