static takeRawFloatTex(sizePower) {
        return WglTexturePool.take(
            sizePower,
            WebGLRenderingContext.FLOAT);
    }
Allocates a FLOAT RGBA texture with an area of 1<<sizePower.

Some GPUs don't support rendering to and/or reading pixels from float textures. If you want the floats to be
encoded into bytes if necessary, use takeVecFloatTex instead.

@param {!int} sizePower
@returns {!WglTexture}