Support for half float textures

[marklundin]

Like the title says, It would be really handy to add support for half float textures. This would be really beneficial for mobile devices

I'm not sure how the api would look, however the current preferFloat, float is a bit error prone and ambiguous if you consider { float:false, preferFloat:true }. Could it be better to just pass int gl.FLOAT or ext.HALF_FLOAT_OES directly?

[mikolalysenko]

Hmm... Maybe the way to deal with this is to have the precision be some string parameter?

Perhaps the user cold specify an argument like:

{ float: '>16' } Need at least half float
{ float: '32' } Need exactly float
{ float:>8} Use highest available precision

[marklundin]

Was also thinking about some bit flag, like {format: FLOAT | HALF_FLOAT | UNSIGNED_BYTE } so you can set the preferred order. Not sure if that makes sense though

[mikolalysenko]

Maybe.. Sometimes with float textures it is desirable to have them as an upgradeable option, since maybe you can use lower precision and get away with it. Perhaps you could specify a list of precisions like:

{ precision: [32, 16, 8] }

[marklundin]

Yeah, that makes more sense to me, although I can't imagine a scenario wher you'd require [ 8, 32, 16] or something out of order.

[mikolalysenko]

I guess if you put 8 first, you'll always get it. But there might be situations where maybe you'd prefer 32 vs 16 in different orders (based on memory restrictions). I'm open to suggestions here on alternative ways to do this.

[neomantra]

I took a slightly different approach from the precision idea. I added two options, halfFloat and preferHalfFloat. So now we have:

• float: must be 32-bit
• halfFloat: must be 16-bit
• preferFloat: equivalent to precision: [32, 16, 8] in the ideas above
• preferHalfFloat: equivalent to precision: [16, 32, 8]

I also probe if these are actually renderable by the context. It's a little extra work, but FBOs shouldn't be created very often.

EDIT: had mistyped preferHalfFloat as preferFloat in the bullets

[benwest]

yes! please merge this!!