WEBGL_compressed_texture_es3

The WEBGL_compressed_texture_es3 extension is part of the WebGL API and exposes 10 ETC/EAC compressed texture formats.

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 only available to WebGL1 contexts. In WebGL2, the functionality of this extension is available on the WebGL2 context by default.

Constants

The compressed texture formats are exposed by 10 constants and can be used in two functions: compressedTexImage2D() and compressedTexSubImage2D().

ext.COMPRESSED_R11_EAC
One-channel (red) unsigned format compression.
ext.COMPRESSED_SIGNED_R11_EAC
One-channel (red) signed format compression.
ext.COMPRESSED_RG11_EAC
Two-channel (red and green) unsigned format compression.
ext.COMPRESSED_SIGNED_RG11_EAC
Two-channel (red and green) signed format compression.
ext.COMPRESSED_RGB8_ETC2
Compresses RGB8 data with no alpha channel.
ext.COMPRESSED_RGBA8_ETC2_EAC
Compresses RGBA8 data. The RGB part is encoded the same as RGB_ETC2, but the alpha part is encoded separately.
ext.COMPRESSED_SRGB8_ETC2
Compresses sRGB8 data with no alpha channel.
ext.COMPRESSED_SRGB8_ALPHA8_ETC2_EAC
Compresses sRGBA8 data. The sRGB part is encoded the same as SRGB_ETC2, but the alpha part is encoded separately.
ext.COMPRESSED_RGB8_PUNCHTHROUGH_ALPHA1_ETC2
Similar to RGB8_ETC, but with ability to punch through the alpha channel, which means to make it completely opaque or transparent.
ext.COMPRESSED_SRGB8_PUNCHTHROUGH_ALPHA1_ETC2
Similar to SRGB8_ETC, but with ability to punch through the alpha channel, which means to make it completely opaque or transparent.

Examples

var ext = gl.getExtension("WEBGL_compressed_texture_es3");

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

gl.compressedTexImage2D(gl.TEXTURE_2D, 0, ext.COMPRESSED_RGBA8_ETC2_EAC, 512, 512, 0, textureData); 

Specifications

Specification Status Comment
WEBGL_compressed_texture_es3
The definition of 'WEBGL_compressed_texture_es3' in that specification.
Draft Initial definition.

Browser compatibility

Feature Chrome Edge Firefox Internet Explorer Opera Safari Servo
Basic Support??46.0????
Feature Android Chrome for Android Edge Mobile Firefox for Android IE Mobile Opera Mobile Safari Mobile
Basic Support???????

See also

Document Tags and Contributors

 Contributors to this page: teoli, fscholz
 Last updated by: teoli,