Function vtflib_sys::vlImageGenerateNormalMap

pub unsafe extern "C" fn vlImageGenerateNormalMap(
    uiFrame: vlUInt, 
    KernelFilter: VTFKernelFilter, 
    HeightConversionMethod: VTFHeightConversionMethod, 
    NormalAlphaResult: VTFNormalAlphaResult
) -> vlBool