WEBGL_compressed_texture_astc extension
The WEBGL_compressed_texture_astc
extension is part of the WebGL API and exposes Adaptive Scalable Texture Compression (ASTC) compressed texture formats to WebGL.
For more information, see the article Using ASTC Texture Compression for Game Assets by NVIDIA.
WebGL extensions are available using the WebGLRenderingContext.getExtension()
method. For more information, see also Using Extensions in the WebGL tutorial.
Instance methods
This extension exposes one new methods.
ext.getSupportedProfiles()
-
Returns an array of strings containing the names of the ASTC profiles supported by the implementation.
Constants
The compressed texture formats are exposed by 28 constants and can be used in two functions: compressedTexImage2D()
and compressedTexSubImage2D()
.
Constants | Blocks | Bits per pixel | ArrayBuffer byteLength |
bytes if height and width are 512 |
---|---|---|---|---|
ext.COMPRESSED_RGBA_ASTC_4x4_KHR |
4x4 | 8.00 | floor((width + 3) / 4) * floor((height + 3) / 4) * 16 |
262144 |
ext.COMPRESSED_RGBA_ASTC_5x4_KHR |
5x4 | 6.40 | floor((width + 4) / 5) * floor((height + 3) / 4) * 16 |
210944 |
ext.COMPRESSED_RGBA_ASTC_5x5_KHR |
5x5 | 5.12 | floor((width + 4) / 5) * floor((height + 4) / 5) * 16 |
169744 |
ext.COMPRESSED_RGBA_ASTC_6x5_KHR |
6x5 | 4.27 | floor((width + 5) / 6) * floor((height + 4) / 5) * 16 |
141728 |
ext.COMPRESSED_RGBA_ASTC_6x6_KHR |
6x6 | 3.56 | floor((width + 5) / 6) * floor((height + 5) / 6) * 16 |
118336 |
ext.COMPRESSED_RGBA_ASTC_8x5_KHR |
8x5 | 3.20 | floor((width + 7) / 8) * floor((height + 4) / 5) * 16 |
105472 |
ext.COMPRESSED_RGBA_ASTC_8x6_KHR |
8x6 | 2.67 | floor((width + 7) / 8) * floor((height + 5) / 6) * 16 |
88064 |
ext.COMPRESSED_RGBA_ASTC_8x8_KHR |
8x8 | 2.00 | floor((width + 7) / 8) * floor((height + 7) / 8) * 16 |
65536 |
ext.COMPRESSED_RGBA_ASTC_10x5_KHR |
10x5 | 2.56 | floor((width + 9) / 10) * floor((height + 4) / 5) * 16 |
85696 |
ext.COMPRESSED_RGBA_ASTC_10x6_KHR |
10x6 | 2.13 | floor((width + 9) / 10) * floor((height + 5) / 6) * 16 |
71552 |
ext.COMPRESSED_RGBA_ASTC_10x8_KHR |
10x8 | 1.60 | floor((width + 9) / 10) * floor((height + 7) / 8) * 16 |
53248 |
ext.COMPRESSED_RGBA_ASTC_10x10_KHR |
10x10 | 1.28 | floor((width + 9) / 10) * floor((height + 9) / 10) * 16 |
43264 |
ext.COMPRESSED_RGBA_ASTC_12x10_KHR |
12x10 | 1.07 | floor((width + 11) / 12) * floor((height + 9) / 10) * 16 |
35776 |
ext.COMPRESSED_RGBA_ASTC_12x12_KHR |
12x12 | 0.89 | floor((width + 11) / 12) * floor((height + 11) / 12) * 16 |
29584 |
Examples
js
const ext = gl.getExtension("WEBGL_compressed_texture_astc");
const texture = gl.createTexture();
gl.bindTexture(gl.TEXTURE_2D, texture);
gl.compressedTexImage2D(
gl.TEXTURE_2D,
0,
ext.COMPRESSED_RGBA_ASTC_12x12_KHR,
512,
512,
0,
textureData
);
Specifications
Specification |
---|
WebGL WEBGL_compressed_texture_astc Extension Specification |
Browser compatibility
BCD tables only load in the browser