WEBGL_compressed_texture_s3tc_srgb - Web APIs 编辑

The WEBGL_compressed_texture_s3tc_srgb extension is part of the WebGL API and exposes four S3TC compressed texture formats for the sRGB colorspace.

Compressed textures reduce the amount of memory needed to store a texture on the GPU, allowing for higher resolution textures or more of the same resolution textures.

WebGL extensions are available using the WebGLRenderingContext.getExtension() method. For more information, see also Using Extensions in the WebGL tutorial.

Availability: This extension is available to both WebGL1 and WebGL2 contexts.

Constants

The compressed texture formats are exposed by four constants and can be used in two functions: compressedTexImage2D() and compressedTexSubImage2D().

ext.COMPRESSED_SRGB_S3TC_DXT1_EXT

A DXT1-compressed image in an sRGB image format.

ext.COMPRESSED_SRGB_ALPHA_S3TC_DXT1_EXT

A DXT1-compressed image in an sRGB image format with a simple on/off alpha value.

ext.COMPRESSED_SRGB_ALPHA_S3TC_DXT3_EXT

A DXT3-compressed image in an sRGBA image format.

ext.COMPRESSED_SRGB_ALPHA_S3TC_DXT5_EXT

A DXT5-compressed image in an sRGBA image format.

Examples

var ext = gl.getExtension('WEBGL_compressed_texture_s3tc_srgb');

var texture = gl.createTexture();
gl.bindTexture(gl.TEXTURE_2D, texture);

gl.compressedTexImage2D(gl.TEXTURE_2D, 0, ext.COMPRESSED_SRGB_S3TC_DXT1_EXT, 512, 512, 0, textureData);

gl.texParameteri(gl.TEXTURE_2D, gl.TEXTURE_MAG_FILTER, gl.LINEAR);
gl.texParameteri(gl.TEXTURE_2D, gl.TEXTURE_MIN_FILTER, gl.LINEAR);

Specifications

Browser compatibility

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The compatibility table in this page is generated from structured data. If you'd like to contribute to the data, please check out https://github.com/mdn/browser-compat-data and send us a pull request.

See also

• S3 Texture Compression – OpenGL wiki
• WebGLRenderingContext.getExtension()
• WebGLRenderingContext.compressedTexImage2D()
• WebGLRenderingContext.compressedTexSubImage2D()
• WebGLRenderingContext.getParameter()