glEnable — enable or disable server-side GL capabilities
void glEnable( | GLenum cap); |
void glDisable( | GLenum cap); |
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_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_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 UNSIGNED_BYTE, UNSIGNED_SHORT,
or 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_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.
glBlendFunc, glCullFace, glDepthFunc, glDepthRangef, glGet, glIsEnabled, glPolygonOffset, glSampleCoverage, glScissor, glStencilFunc, glStencilOp,
Copyright © 1991-2006 Silicon Graphics, Inc. Copyright © 2010-2012 Khronos Group. This document is licensed under the SGI Free Software B License. For details, see http://oss.sgi.com/projects/FreeB/.