proc initOpenGl(log: proc (messages: string) = log;
               hints: array[OglHint, OglHintMode] = defaultHints;
               flags: set[OglFlag] = {}; clearDepth: float = 1.0;
               depthFunc: OglDepthFunc = OglDepthFunc.Lequal;
               clearColor: tuple[r, g, b, a: float] = (0.0, 0.0, 0.0, 1.0);
               shadeModel: OglShadeModel = OglShadeModel.Smooth;
               sourceBlendFactor: OglBlendFunc = OglBlendFunc.SrcAlpha;
    destinationBlendFactor: OglBlendFunc = OglBlendFunc.OneMinusSrcAlpha; screenSize: Option[
    tuple[width, height: int]] = none(tuple[width, height: int])) {...}{.
    raises: [GLerror, UnpackError], tags: [].}

template clear(bits: set[OglClear] = {ColorBufferBit, DepthBufferBit})

template isEnabled(flag: OglFlag): bool