WEBGL_compressed_texture_s3tc_srgb extension

Limited availability

This feature is not Baseline because it does not work in some of the most widely-used browsers.

TheWEBGL_compressed_texture_s3tc_srgb extension is part of theWebGL API and exposes fourS3TC 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 theWebGLRenderingContext.getExtension() method. For more information, see alsoUsing Extensions in theWebGL tutorial.

Note:This extension is available to bothWebGL1 andWebGL2 contexts.

Constants

The compressed texture formats are exposed by four constants and can be used in two functions:compressedTexImage2D() andcompressedTexSubImage2D().

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 an 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

const ext = gl.getExtension("WEBGL_compressed_texture_s3tc_srgb");const 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);