Function imgui_sys::igImageButton

pub unsafe extern fn igImageButton(
    user_texture_id: ImTextureID, 
    size: ImVec2, 
    uv0: ImVec2, 
    uv1: ImVec2, 
    frame_padding: c_int, 
    bg_col: ImVec4, 
    tint_col: ImVec4
) -> bool