function canGenerateMipmap(gl, width, height, internalFormat /*, type */) {
	    if (!utils.isWebGL2(gl)) {
	      return isPowerOf2(width) && isPowerOf2(height);
	    }
	    var info = textureInternalFormatInfo[internalFormat];
	    if (!info) {
	      throw "unknown internal format";
	    }
	    return info.colorRenderable && info.textureFilterable;
	  }
Gets whether or not we can generate mips for the given format
@param {number} internalFormat The internalFormat parameter from texImage2D etc..
@param {number} type The type parameter for texImage2D etc..
@return {boolean} true if we can generate mips