declare shader
    struct { geometry "instance", 
             color "color",
             vector "normal" }
        "c_toon_store" ()
    version 1
    apply texture
end declare

declare shader
    "c_toon_contrast" (
        scalar "dot_threshold" default 0.71 )
    version 1
    apply texture
end declare

declare shader
    "c_toon_contour" (
        color "color" default 0 0 0 1,
        scalar "width" default 1 )
    version 1
    apply texture
end declare