Function rin::gl::image_based_light::copy_equirectangular_levels_to_cubemap

pub fn copy_equirectangular_levels_to_cubemap<T, I>(
    levels: I, 
    cubemap: &mut CubeMap, 
    gl: &Renderer<'_, Screen>
) where
    T: Borrow<Texture>,
    I: IntoIterator<Item = T>, 

Convert a texture containing an equirectangular environment map with several mip levels into a cubemap