GL_OES_compressed_paletted_texture

Supported Hardware

Series5, Series5XT, Series6, Series6XE, Series6XT

Valid APIs

OpenGL ES 1.x

Description

This extension allows the use of paletted textures in OpenGL ES as a compressed texture. Paletted formats are textures which store a small number of colours as a palette, and then the texel array is a simple array of indices into this palette. The benefit of this is that the palette can be cached, and the indices have a lower bandwidth cost than a full colour. This extension allows the colour formats of RGB565, RGBA4444, RGBA551, RGB888 or RGBA8888. Each texel is then allowed to either have a 4- or 8-bit index value, and an appropriate number of palette colours to match.

Note

In subsequent versions of OpenGL ES, this functionality can be easily replicated using programmable shaders by having a small palette texture, and a vertex attribute or another texture specifying the index to use. This allows the functionality to be much more flexible than provided by this extension, so it was dropped.

Registry Link

http://www.khronos.org/registry/gles/extensions/OES/OES_compressed_paletted_texture.txt

Example

// Upload a palletted texture. The size of the data will be dependent on how it was 
// compressed and is thus dependent on whatever tool was used. 
glCompressedTexImage2D(GL_TEXTURE_2D, 0, GL_PALETTE4_RGB8_OES, 1024, 1024, 0, pixelDataSize,
                        pixelData);