#3157 Fix alpha not having ambient lighting on low. (#3162)

* #3157 Fix alpha not having ambient lighting on low.

Author: Geenz

indra/newview/app_settings/shaders/class2/deferred/alphaF.glsl

@@ -36,6 +36,7 @@ out vec4 frag_color;
 uniform mat3 env_mat;
 uniform vec3 sun_dir;
 uniform vec3 moon_dir;
+uniform int classic_mode;
 
 #ifdef USE_DIFFUSE_TEX
 uniform sampler2D diffuseMap;
@@ -241,10 +242,10 @@ void main()
 
     calcAtmosphericVarsLinear(pos.xyz, norm, light_dir, sunlit, amblit, additive, atten);
 
-    vec3 sunlit_linear = srgb_to_linear(sunlit);
+    vec3 sunlit_linear = sunlit;
     vec3 amblit_linear = amblit;
 
-    vec3 irradiance;
+    vec3 irradiance = amblit;
     vec3 glossenv;
     vec3 legacyenv;
     sampleReflectionProbesLegacy(irradiance, glossenv, legacyenv, frag, pos.xyz, norm.xyz, 0.0, 0.0, true, amblit_linear);
@@ -260,11 +261,20 @@ void main()
 
     color.a   = final_alpha;
 
-    vec3 sun_contrib = min(final_da, shadow) * sunlit_linear;
-
     color.rgb = irradiance;
+    if (classic_mode > 0)
+    {
+        final_da = pow(final_da,1.2);
+        vec3 sun_contrib = vec3(min(final_da, shadow));
 
-    color.rgb += sun_contrib;
+        color.rgb = srgb_to_linear(color.rgb * 0.9 + linear_to_srgb(sun_contrib) * sunlit_linear * 0.7);
+        sunlit_linear = srgb_to_linear(sunlit_linear);
+    }
+    else
+    {
+        vec3 sun_contrib = min(final_da, shadow) * sunlit_linear;
+        color.rgb += sun_contrib;
+    }
 
     color.rgb *= diffuse_linear.rgb;
 

indra/newview/app_settings/shaders/class2/deferred/pbralphaF.glsl

@@ -161,7 +161,7 @@ void main()
     vec3 atten;
     calcAtmosphericVarsLinear(pos.xyz, norm, light_dir, sunlit, amblit, additive, atten);
 
-    vec3 sunlit_linear = srgb_to_linear(sunlit);
+    vec3 sunlit_linear = sunlit;
 
     vec2 frag = vary_fragcoord.xy/vary_fragcoord.z*0.5+0.5;
 
@@ -182,7 +182,7 @@ void main()
 
     // PBR IBL
     float gloss      = 1.0 - perceptualRoughness;
-    vec3  irradiance = vec3(0);
+    vec3  irradiance = amblit;
     vec3  radiance  = vec3(0);
     sampleReflectionProbes(irradiance, radiance, vary_position.xy*0.5+0.5, pos.xyz, norm.xyz, gloss, true, amblit);
 

indra/newview/app_settings/shaders/class3/deferred/materialF.glsl

@@ -36,6 +36,7 @@
 
 uniform float emissive_brightness;  // fullbright flag, 1.0 == fullbright, 0.0 otherwise
 uniform int sun_up_factor;
+uniform int classic_mode;
 
 vec4 applySkyAndWaterFog(vec3 pos, vec3 additive, vec3 atten, vec4 color);
 vec3 scaleSoftClipFragLinear(vec3 l);
@@ -329,19 +330,31 @@ void main()
     vec3 atten;
     calcAtmosphericVarsLinear(pos.xyz, norm.xyz, light_dir, sunlit, amblit, additive, atten);
 
-    vec3 sunlit_linear = srgb_to_linear(sunlit);
+    vec3 sunlit_linear = sunlit;
     vec3 amblit_linear = amblit;
 
-    vec3 ambenv;
+    vec3 ambenv = amblit;
     vec3 glossenv;
     vec3 legacyenv;
     sampleReflectionProbesLegacy(ambenv, glossenv, legacyenv, pos.xy*0.5+0.5, pos.xyz, norm.xyz, glossiness, env, true, amblit_linear);
 
     color = ambenv;
 
     float da          = clamp(dot(norm.xyz, light_dir.xyz), 0.0, 1.0);
-    vec3 sun_contrib = min(da, shadow) * sunlit_linear;
-    color.rgb += sun_contrib;
+    if (classic_mode > 0)
+    {
+        da = pow(da,1.2);
+        vec3 sun_contrib = vec3(min(da, shadow));
+
+        color.rgb = srgb_to_linear(color.rgb * 0.9 + linear_to_srgb(sun_contrib) * sunlit_linear * 0.7);
+        sunlit_linear = srgb_to_linear(sunlit_linear);
+    }
+    else
+    {
+        vec3 sun_contrib = min(da, shadow) * sunlit_linear;
+        color.rgb += sun_contrib;
+    }
+
     color *= diffcol.rgb;
 
     vec3 refnormpersp = reflect(pos.xyz, norm.xyz);