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Re: [Public WebGL] Bad news for float textures?



It would be fantastic to get confirmation on this. Should I open a bug for this?

On Wed, Jan 27, 2016 at 6:44 PM, Daniel Koch <dkoch@nvidia.com> wrote:
> I fairly certain this is an oversight in the spec.  The SL docs probably
> never got updated.
>
> -Daniel
>
> On 2016-01-27, 8:19 PM, "owners-public_webgl@khronos.org on behalf of Jeff
> Gilbert" <owners-public_webgl@khronos.org on behalf of jgilbert@mozilla.com>
> wrote:
>
>
> From all of the following SL specs:
> * ESSL 3.0.4 p93
> * GLSL 4.4.9 p160
> * GLSL 4.5.5 p158
>
> " Texture lookups on unsigned normalized integer and floating point
> data return floating point values in the range [0, 1]."
>
> "If a floating point sampler type is used, the result of a texture
> lookup is a vec4, where each component is in the range [0, 1]."
>
>
> The OES_texture_float extension doesn't seem to mention how it affects
> the shading language, if at all. (perhaps this tacitly retains the
> implicit range of [0,1] of unsigned normalized fixed-point)
>
> Now clearly out-of-range (> 1.0) values often work in the real world
> (the conformance tests even require this!), but I don't know which (if
> any) extension actually guarantees this. It seems clear in the core
> specs that the range is limited even for floating-point textures.
>
> Should we:
> * Make out-of-range sampling explicitly optional
> * Require out-of-range sampling explicitly
> * Attach out-of-range sampling to an extension and make its use opt-in
> * Establish if this is an oversight in the GLSL/ESSL spec and get it fixed
> there
>
> It would be good to get Mark's take on this, if there's context we're
> missing.
>
> -Jeff
>
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