From 379dd17b3dc888cef2335909e0af534ed0e60c1b Mon Sep 17 00:00:00 2001
From: Thorsten Renk <thorsten@science-and-fiction.org>
Date: Sun, 12 Jun 2016 15:22:11 +0300
Subject: [PATCH] ALS maintenance: bugfix for cloud impostors, 'inverse' Mie
 for cloud shader, glare for translucent objects proportional to 1-alpha
 rather than on-off

---
 Effects/cloud-impostor.eff   | 42 ++++++++++++++++++++++++++++++++++++
 Shaders/3dcloud-ALS.vert     | 26 ++++++++++++++++++----
 Shaders/model-ALS-ultra.frag |  4 ++--
 3 files changed, 66 insertions(+), 6 deletions(-)

diff --git a/Effects/cloud-impostor.eff b/Effects/cloud-impostor.eff
index 6540e0025..9ef756587 100644
--- a/Effects/cloud-impostor.eff
+++ b/Effects/cloud-impostor.eff
@@ -60,6 +60,8 @@
       <program>
         <vertex-shader>Shaders/cloud-impostor-ALS.vert</vertex-shader>
         <fragment-shader>Shaders/cloud-static-ALS.frag</fragment-shader>
+ 	<fragment-shader>Shaders/noise.frag</fragment-shader>
+        <fragment-shader>Shaders/filters-ALS.frag</fragment-shader>
       </program>
       <uniform>
         <name>baseTexture</name>
@@ -96,6 +98,46 @@
         <type>float</type>
         <value><use>air_pollution</use></value>
       </uniform>
+      <uniform>
+        <name>gamma</name>
+        <type>float</type>
+        <value><use>gamma</use></value>
+      </uniform>
+      <uniform>
+        <name>brightness</name>
+        <type>float</type>
+        <value><use>brightness</use></value>
+      </uniform>
+      <uniform>
+        <name>use_filtering</name>
+        <type>bool</type>
+        <value><use>use_filtering</use></value>
+      </uniform>
+      <uniform>
+        <name>use_night_vision</name>
+        <type>bool</type>
+        <value><use>use_night_vision</use></value>
+      </uniform>
+      <uniform>
+        <name>use_IR_vision</name>
+        <type>bool</type>
+        <value><use>use_IR_vision</use></value>
+      </uniform>
+      <uniform>
+        <name>delta_T</name>
+        <type>float</type>
+        <value><use>delta_T</use></value>
+      </uniform>
+      <uniform>
+        <name>display_xsize</name>
+        <type>int</type>
+        <value><use>display_xsize</use></value>
+      </uniform>
+      <uniform>
+        <name>display_ysize</name>
+        <type>int</type>
+        <value><use>display_ysize</use></value>
+      </uniform>  
       <vertex-program-two-side>true</vertex-program-two-side>
     </pass>
   </technique>
diff --git a/Shaders/3dcloud-ALS.vert b/Shaders/3dcloud-ALS.vert
index 6c273e14d..c729bf0e0 100644
--- a/Shaders/3dcloud-ALS.vert
+++ b/Shaders/3dcloud-ALS.vert
@@ -209,15 +209,16 @@ void main(void)
 
    
     // Mie correction
-    float Mie;
-    float MieFactor;
+    float Mie = 0.0;
+    float MieFactor = 0.0;
 
-     if (bottom_factor > 0.6) 
+     if (bottom_factor > 0.4) 
     {
     MieFactor =   dot(normalize(lightFull), normalize(relVector));
     Mie = 1.5 * smoothstep(0.9,1.0, MieFactor) * smoothstep(0.6, 0.8, bottom_factor) * (1.0-earthShadeFactor) ;  
+   //if (MieFactor < 0.0) {Mie = - Mie;}
     }
-     else {Mie = 0.0;}
+     //else {Mie = 0.0;}
 
      if (Mie > 0.0)
       {
@@ -229,6 +230,23 @@ void main(void)
     gl_FrontColor.g = mie_func(gl_FrontColor.g, 0.8* Mie);
     gl_FrontColor.b = mie_func(gl_FrontColor.b, 0.5*Mie);
     }
+     else if (MieFactor < 0.0)
+     {
+    float thickness_reduction = smoothstep(0.4, 0.8, bottom_factor) ;
+    float light_reduction = dot (lightFull, lightHorizon);
+    light_reduction *= light_reduction;
+
+    float factor_b = 0.8 + 0.2 * (1.0 - smoothstep(0.0, 0.7, -MieFactor) * thickness_reduction * light_reduction) ;
+    float factor_r = 0.6 + 0.4 * (1.0 - smoothstep(0.0, 0.7, -MieFactor) * thickness_reduction * light_reduction) ;
+    float factor_g = 0.65 + 0.35 * (1.0 - smoothstep(0.0, 0.7, -MieFactor) * thickness_reduction * light_reduction) ;
+    hazeColor.r *= factor_r; 
+    hazeColor.g *= factor_g;
+    hazeColor.b *= factor_b;
+
+    gl_FrontColor.r *= factor_r; 
+    gl_FrontColor.g *= factor_g;
+    gl_FrontColor.b *= factor_b;
+     }
    
     gl_FrontColor.rgb = gl_FrontColor.rgb +  moonLightColor * earthShadeFactor;
     hazeColor.rgb = hazeColor.rgb + moonLightColor * earthShadeFactor;
diff --git a/Shaders/model-ALS-ultra.frag b/Shaders/model-ALS-ultra.frag
index 04aa8dbd8..a57fdbbd5 100644
--- a/Shaders/model-ALS-ultra.frag
+++ b/Shaders/model-ALS-ultra.frag
@@ -253,8 +253,8 @@ void main (void)
     //glare on the backside of tranparent objects
     if ((gl_FrontMaterial.diffuse.a < 1.0 || texel.a < 1.0)
         && dot(N, normalize(gl_LightSource[0].position.xyz)) < 0.0) {
-            nDotVP = max(0.0, dot(-N, normalize(gl_LightSource[0].position.xyz)));
-            nDotHV = max(0.0, dot(-N, normalize(gl_LightSource[0].halfVector.xyz)));
+            nDotVP = max(0.0, dot(-N, normalize(gl_LightSource[0].position.xyz)) * (1.0 -texel.a) );
+            nDotHV = max(0.0, dot(-N, normalize(gl_LightSource[0].halfVector.xyz)) * (1.0 -texel.a) );
         }
 
     float nDotVP1 = 0.0;