From 33058f2b292b3a581333bdfb21b8f671898c5060 Mon Sep 17 00:00:00 2001 From: Peter Bengtsson Date: Tue, 8 Dec 2020 14:40:17 -0500 Subject: initial commit --- .../api/webglrenderingcontext/isenabled/index.html | 193 +++++++++++++++++++++ 1 file changed, 193 insertions(+) create mode 100644 files/zh-cn/web/api/webglrenderingcontext/isenabled/index.html (limited to 'files/zh-cn/web/api/webglrenderingcontext/isenabled/index.html') diff --git a/files/zh-cn/web/api/webglrenderingcontext/isenabled/index.html b/files/zh-cn/web/api/webglrenderingcontext/isenabled/index.html new file mode 100644 index 0000000000..9c87ead999 --- /dev/null +++ b/files/zh-cn/web/api/webglrenderingcontext/isenabled/index.html @@ -0,0 +1,193 @@ +--- +title: WebGLRenderingContext.isEnabled() +slug: Web/API/WebGLRenderingContext/isEnabled +translation_of: Web/API/WebGLRenderingContext/isEnabled +--- +
{{APIRef("WebGL")}}
+ +

WebGLRenderingContext.isEnabled() 是 WebGL API 方法之一，用来检测给定的 WebGL 功能项在当前上下文是否可用。

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默认的，除了 gl.DITHER，所有的功能项都是未启用的。

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句法

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void gl.isEnabled(cap);
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参数

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cap
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{{domxref("GLenum")}} 指定待检测的 WebGL 功能项。可能的值有：
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ConstantDescription
gl.BLENDBlending of the computed fragment color values. See {{domxref("WebGLRenderingContext.blendFunc()")}}.
gl.CULL_FACECulling of polygons. See {{domxref("WebGLRenderingContext.cullFace()")}}.
gl.DEPTH_TESTDepth comparisons and updates to the depth buffer. See {{domxref("WebGLRenderingContext.depthFunc()")}}.
gl.DITHERDithering of color components before they get written to the color buffer.
gl.POLYGON_OFFSET_FILLAdding an offset to depth values of polygon's fragments. See {{domxref("WebGLRenderingContext.polygonOffset()")}}.
gl.SAMPLE_ALPHA_TO_COVERAGEComputation of a temporary coverage value determined by the alpha value.
gl.SAMPLE_COVERAGEANDing the fragment's coverage with the temporary coverage value. See {{domxref("WebGLRenderingContext.sampleCoverage()")}}.
gl.SCISSOR_TESTScissor test that discards fragments that are outside of the scissor rectangle. See {{domxref("WebGLRenderingContext.scissor()")}}.
gl.STENCIL_TESTStencil testing and updates to the stencil buffer. See {{domxref("WebGLRenderingContext.stencilFunc()")}}.
+ 当使用 {{domxref("WebGL2RenderingContext", "WebGL 2 context", "", 1)}} 的时候，下列附加的值也是可选用的。 + + + + + + + + + + + + + + +
ConstantDescription
gl.RASTERIZER_DISCARDPrimitives are discarded immediately before the rasterization stage, but after the optional transform feedback stage. gl.clear() commands are ignored.
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返回值

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{{domxref("GLboolean")}} 指示能力项 cap 可用 (true)，不可用 (false)。

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示例

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gl.isEnabled(gl.STENCIL_TEST);
+// false
+
+ +

启用或停用给定的能力项，使用 {{domxref("WebGLRenderingContext.enable()")}} 方法和 {{domxref("WebGLRenderingContext.disable()")}} 方法：

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gl.enable(gl.STENCIL_TEST);
+gl.disable(gl.STENCIL_TEST);
+
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规范

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SpecificationStatusComment
{{SpecName('WebGL', "#5.14.3", "isEnabled")}}{{Spec2('WebGL')}}Initial definition for WebGL.
{{SpecName('OpenGL ES 2.0', "glIsEnabled.xml", "glIsEnabled")}}{{Spec2('OpenGL ES 2.0')}}Man page of the (similar) OpenGL ES 2.0 API.
{{SpecName('WebGL2', "#3.7.2", "isEnabled")}}{{Spec2('WebGL2')}}Updated definition for WebGL 2.
{{SpecName('OpenGL ES 3.0', "glIsEnabled.xhtml", "glIsEnabled")}}{{Spec2('OpenGL ES 3.0')}}Man page of the (similar) OpenGL ES 3.0 API.
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浏览器兼容性

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{{CompatibilityTable}}
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FeatureChromeFirefox (Gecko)Internet ExplorerOperaSafari
Basic support{{CompatChrome("9")}}{{CompatGeckoDesktop("2.0")}}{{CompatIE("11")}}{{CompatOpera("12")}}{{CompatSafari("5.1")}}
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FeatureAndroidChrome for AndroidFirefox Mobile (Gecko)IE MobileOpera MobileSafari Mobile
Basic support{{CompatUnknown}}25{{CompatVersionUnknown}}{{CompatUnknown}}128.1
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另见

+ + -- cgit v1.2.3-54-g00ecf