Make the material shaders physically based

shaders/mat_sunlessnormalmap_specgloss.frag

@@ -34,77 +34,6 @@ uniform sampler2D specgloss;
 #include <apply_fog.glsl>
 #include <tonemapping.glsl>
 
-vec3 apply_lights_sunless(vec3 fragcolor, vec3 fragnormal, vec3 texturecolor, float reflectivity, float specularity, float shadowtone)
-{
-    // diffuse colour applied once, to the albedo (see material_diffuse() in light_common.glsl)
-    texturecolor *= material_diffuse();
-    // Cab interior: dim ambient less than the exterior path - ambient
-    // is the dominant indoor illumination, but it was still too bright.
-    fragcolor *= 0.80;
-
-    vec3 emissioncolor = vec3(emission);
-
-    vec3 view_dir = normalize(-f_pos.xyz);
-    float NdotV = max(dot(fragnormal, view_dir), 0.0);
-    vec3 F0 = mix(vec3(0.04), texturecolor, metalic);
-    vec3 fresnel = F0 + (1.0 - F0) * pow(1.0 - NdotV, 5.0);
-
-    float env_roughness = 1.0 - clamp(glossiness / max(abs(param[1].w), 1.0), 0.0, 1.0);
-    vec3 envcolor = envmap_color_rough(fragnormal, env_roughness);
-
-    // Pre-integrated env BRDF (matches apply_lights): roughness-attenuated
-    // reflection so matte cab surfaces no longer mirror the environment.
-    vec3 env_spec = EnvBRDFApprox(F0, env_roughness, NdotV);
-    float env_spec_w = max(env_spec.r, max(env_spec.g, env_spec.b));
-
-    vec3 texturecoloryuv = rgb2yuv(texturecolor);
-    vec3 texturecolorfullv = yuv2rgb(vec3(0.2176, texturecoloryuv.gb));
-    vec3 envyuv = rgb2yuv(envcolor);
-    texturecolor = mix(texturecolor, texturecolorfullv, envyuv.r * reflectivity * env_spec_w);
-
-    if (lights_count == 0U)
-        return fragcolor * texturecolor * (1.0 - metalic)
-             + emissioncolor * texturecolor
-             + envcolor * env_spec * reflectivity;
-
-    vec2 sunlight = calc_dir_light(lights[0], fragnormal);
-    // Sharpen N.L for stronger contrast between lit and shaded cab
-    // surfaces (uses SUN_NDOTL_SHARPNESS from light_common.glsl).
-    float sun_NdotL = pow(sunlight.x, SUN_NDOTL_SHARPNESS);
-    float diffuseamount = sun_NdotL * lights[0].intensity;
-    // the clouds hold back the sun where their shadow falls, as the shadow map does
-    float cloudsun = cloud_shadow(mat3(inv_view) * f_pos.xyz);
-
-    float specularamount = sunlight.y * param[1].y * specularity * lights[0].intensity * cloudsun;
-
-    fragcolor = add_headlights(fragcolor, fragnormal);
-
-    if (shadowtone < 1.0)
-    {
-        float shadow = max(calc_shadow(), 1.0 - cloudsun);
-        specularamount *= clamp(1.0 - shadow, 0.0, 1.0);
-        fragcolor = mix(fragcolor, fragcolor * shadowtone, clamp(diffuseamount * shadow, 0.0, 1.0));
-    }
-
-    vec3 specularcolor = specularamount * lights[0].color;
-
-    // Env reflection gated by env BRDF (roughness-attenuated, F0-tinted).
-    vec3 env_reflection = envcolor * env_spec * reflectivity;
-
-    // Physically-based metal/rough combine (matches apply_lights / Substance):
-    // dielectric -> light-coloured highlight + full diffuse; metal -> albedo-tinted
-    // highlight, no diffuse term. Highlight strength left unchanged.
-    vec3 diffuse_albedo = texturecolor * (1.0 - metalic);
-    vec3 spec_tint      = mix(vec3(1.0), texturecolor, metalic);
-
-    vec3 result = fragcolor      * diffuse_albedo
-                + specularcolor  * spec_tint
-                + emissioncolor  * texturecolor
-                + env_reflection;   // env_spec already F0-tinted for metals
-
-    return result;
-}
-
 void main()
 {
 	vec4 tex_color = texture(diffuse, f_coord);