Constant USER_WARP_FRAGMENT_SUFFIX 

const USER_WARP_FRAGMENT_SUFFIX: &str = r#"
    // ---- end translated user body ----

    return vec4<f32>(ret, 1.0);
}
"#;

Fragment-shader trailer for the warp pass. Same convention as the comp suffix (return vec4(ret, 1.0)), minus the gamma_adj factor — gamma is a display-side concern applied later in the comp pass.