Function imgui_sys::ImFontAtlas_AddCustomRectFontGlyph

pub unsafe extern "C" fn ImFontAtlas_AddCustomRectFontGlyph(
    this: *mut ImFontAtlas, 
    font: *mut ImFont, 
    id: ImWchar, 
    width: c_int, 
    height: c_int, 
    advance_x: c_float, 
    offset: ImVec2
) -> c_int