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webgl extension

WEBGL_compressed_texture_s3tc_srgb extension

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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 getExtension() method. For more information, see also Using Extensions in the WebGL tutorial.

[!NOTE] 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 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);

Specifications

SpecificationsStandards references are available on the canonical MDN page.

Browser compatibility

Browser compatibilityCompatibility data is available on the canonical MDN page.

See also