static takeVec4Tex(sizePower) {
        return WglTexturePool.take(
            sizePower + currentShaderCoder().vec4.powerSizeOverhead,
            currentShaderCoder().vec4.pixelType);
    }
Allocates a texture for storing an encoded array of 1<<sizePower float-quadruplets (possibly encoded into bytes).

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