The WebGLRenderingContext.isEnabled()
method of the WebGL API tests whether a specific WebGL capability is enabled or not for this context.
By default, all capabilities except gl.DITHER
are disabled.
Syntax
void gl.isEnabled(cap);
Parameters
cap
- A
GLenum
specifying which WebGL capability to test. Possible values: -
Constant Description gl.BLEND
Blending of the computed fragment color values. See WebGLRenderingContext.blendFunc()
.gl.CULL_FACE
Culling of polygons. See WebGLRenderingContext.cullFace()
.gl.DEPTH_TEST
Depth comparisons and updates to the depth buffer. See WebGLRenderingContext.depthFunc()
.gl.DITHER
Dithering of color components before they get written to the color buffer. gl.POLYGON_OFFSET_FILL
Adding an offset to depth values of polygon's fragments. See WebGLRenderingContext.polygonOffset()
.gl.SAMPLE_ALPHA_TO_COVERAGE
Computation of a temporary coverage value determined by the alpha value. gl.SAMPLE_COVERAGE
ANDing the fragment's coverage with the temporary coverage value. See WebGLRenderingContext.sampleCoverage()
.gl.SCISSOR_TEST
Scissor test that discards fragments that are outside of the scissor rectangle. See WebGLRenderingContext.scissor()
.gl.STENCIL_TEST
Stencil testing and updates to the stencil buffer. See WebGLRenderingContext.stencilFunc()
.Constant Description gl.RASTERIZER_DISCARD
Primitives are discarded immediately before the rasterization stage, but after the optional transform feedback stage. gl.clear()
commands are ignored.
Return value
A GLboolean
indicating if the capability cap is enabled (true
), or not (false
).
Examples
gl.isEnabled(gl.STENCIL_TEST); // false
To activate or deactivate a specific capability, use the WebGLRenderingContext.enable()
and WebGLRenderingContext.disable()
methods:
gl.enable(gl.STENCIL_TEST); gl.disable(gl.STENCIL_TEST);
Specifications
Specification | Status | Comment |
---|---|---|
WebGL 1.0 The definition of 'isEnabled' in that specification. |
Recommendation | Initial definition for WebGL. |
OpenGL ES 2.0 The definition of 'glIsEnabled' in that specification. |
Standard | Man page of the (similar) OpenGL ES 2.0 API. |
WebGL 2.0 The definition of 'isEnabled' in that specification. |
Editor's Draft | Updated definition for WebGL 2. |
OpenGL ES 3.0 The definition of 'glIsEnabled' in that specification. |
Standard | Man page of the (similar) OpenGL ES 3.0 API. |
Browser compatibility
Feature | Chrome | Firefox (Gecko) | Internet Explorer | Opera | Safari |
---|---|---|---|---|---|
Basic support | 9 | 4.0 (2.0) | 11 | 12 | 5.1 |
Feature | Android | Chrome for Android | Firefox Mobile (Gecko) | IE Mobile | Opera Mobile | Safari Mobile |
---|---|---|---|---|---|---|
Basic support | ? | 25 | (Yes) | ? | 12 | 8.1 |