Re: [Public WebGL] Restricting WebGL exposure of OES_depth_texture

[Florian Bösch <pyalot@gmail.com>]

On Sun, Jul 1, 2012 at 12:23 PM, Yvonne Jung <yvonne.jung@igd.fraunhofer.de> wrote:

thank you for your help! However, I would have liked to use reading back floats exactly for getting rid of such encodings and to improve performance. My use case is simply that I want to improve buffer-based picking by encoding the fragment's position - including an integer object ID - into one floating point RGBA texture to avoid additional calculations and render passes. Are there any plans to include FLOAT readback from an FBO in the near future?

Floating point readback is not supported by vanilla OpenGL ES 2.0. So if that functionality where to be provided, it would have to be an extension.

However the OES extension registry (http://www.khronos.org/registry/gles/) does not list any extension that lets you perform floating point readbacks as far as I can see.

It is very likely that you cannot render to floating point textures on mobiles, and even if you can, it is certain that you cannot read back from floating point targets.

Because the policy is upheld by the Khronos WebGL-WG that no desktop only functionality should be introduced to WebGL, it is therefore impossible to introduce an extension to provide this because it would only work on desktops.