From 459d8a02e0e9a1faa84902795c1bd4fab30bf863 Mon Sep 17 00:00:00 2001
From: Thorsten Renk <thorsten.i.renk@jyu.fi>
Date: Sun, 10 Jan 2016 13:00:15 +0200
Subject: [PATCH] Simple Aurora Borealis strength manager dependent on viewer
 latitude

---
 Environment/environment.xml          |  1 +
 Environment/local-weather-rules.xml  | 73 ++++++++++++++++++++++++++++
 Shaders/skydome-ALS.frag             |  2 +-
 gui/dialogs/environment-settings.xml | 47 ++++++++++++++++++
 4 files changed, 122 insertions(+), 1 deletion(-)

diff --git a/Environment/environment.xml b/Environment/environment.xml
index 248650d04..0d990dc8e 100644
--- a/Environment/environment.xml
+++ b/Environment/environment.xml
@@ -441,6 +441,7 @@
  <!-- definitions for aurorae -->
 
   <aurora>
+    <set-strength type="double" userarchive="n">0.0</set-strength>
     <strength type="double" userarchive="n">0.0</strength>
     <vsize type="double" userarchive="n">0.4</vsize>
     <hsize type="double" userarchive="n">0.4</hsize>
diff --git a/Environment/local-weather-rules.xml b/Environment/local-weather-rules.xml
index 006250aed..b17762539 100644
--- a/Environment/local-weather-rules.xml
+++ b/Environment/local-weather-rules.xml
@@ -846,4 +846,77 @@
     <max>1.0</max>
   </filter>
 
+  <filter>
+    <name>EnvironmentInterpolator:Aurora:LatitudeDep</name>
+    <type>gain</type>
+    <gain>1.0</gain>
+    <input>
+        <expression>
+	   <pow>
+	   <div>
+           <abs>
+		<property>/position/latitude-deg</property>
+	   </abs>
+	   <value>90</value>
+  	   </div>
+ 	   <value>2.0</value>
+	  </pow>
+       </expression>
+  </input>
+  <output>/environment/aurora/latitude-scale</output>
+  </filter>
+
+  <filter>
+    <name>EnvironmentInterpolator:Aurora:VerticalSize</name>
+    <type>gain</type>
+    <gain>1.0</gain>
+    <input>
+      <expression>
+	  <max>
+	     <pow>
+		<property>/environment/aurora/latitude-scale</property>
+		<value>2.0</value>
+	     </pow>
+	     <value>0.1</value>
+	  </max>
+      </expression>
+  </input>
+  <output>/environment/aurora/vsize</output>
+  </filter>
+
+  <filter>
+    <name>EnvironmentInterpolator:Aurora:HorizontalSize</name>
+    <type>gain</type>
+    <gain>1.0</gain>
+    <input>
+      <expression>
+	    <max>
+		<property>/environment/aurora/latitude-scale</property>
+		<value>0.1</value>
+	    </max>
+      </expression>
+  </input>
+  <output>/environment/aurora/hsize</output>
+  </filter>
+
+  <filter>
+    <name>EnvironmentInterpolator:Aurora:Strength</name>
+    <type>gain</type>
+    <gain>1.0</gain>
+    <input>
+	<expression>
+	    <product>
+		<pow>
+		  <property>/environment/aurora/latitude-scale</property>
+		  <value>0.5</value>
+		</pow>
+		<property>/environment/aurora/set-strength</property>
+	    </product>
+      </expression>
+  </input>
+  <output>/environment/aurora/strength</output>
+  </filter>
+
+
+
 </PropertyList>
diff --git a/Shaders/skydome-ALS.frag b/Shaders/skydome-ALS.frag
index b3c574772..eb38b09ef 100644
--- a/Shaders/skydome-ALS.frag
+++ b/Shaders/skydome-ALS.frag
@@ -126,7 +126,7 @@ void main()
 
 // Aurora Borealis / Australis
 
-  vec3 direction = vec3 (-1.0, 0.0, 0.0);
+  vec3 direction = vec3 (1.0, 0.0, 0.0);
   
   float hArg = dot(nView, direction);
 
diff --git a/gui/dialogs/environment-settings.xml b/gui/dialogs/environment-settings.xml
index 55a320280..a7eebbba1 100644
--- a/gui/dialogs/environment-settings.xml
+++ b/gui/dialogs/environment-settings.xml
@@ -489,6 +489,53 @@
       <col>3</col>
     </text>
 
+   <text>
+      <enable>
+       <property>/sim/rendering/shaders/skydome</property>
+      </enable>
+      <label> Aurora Borealis</label>
+      <halign>left</halign>
+      <row>10</row>
+      <col>0</col>
+    </text>
+    
+    <text>
+      <enable>
+       <property>/sim/rendering/shaders/skydome</property>
+      </enable>
+      <label>weak</label>
+      <halign>right</halign>
+      <row>10</row>
+      <col>1</col>
+    </text>
+        
+    <slider>
+      <enable>
+       <property>/sim/rendering/shaders/skydome</property>
+      </enable>
+      <name>aurora</name>
+      <row>10</row>
+      <col>2</col>
+      <min>0.0</min>
+      <max>1.0</max>
+      <live>true</live>
+      <property>/environment/aurora/set-strength</property>
+      <binding>
+        <command>dialog-apply</command>
+        <object-name>aurora</object-name>
+      </binding>
+    </slider>
+
+    <text>
+      <enable>
+       <property>/sim/rendering/shaders/skydome</property>
+      </enable>
+      <label>strong</label>
+      <halign>left</halign>
+      <row>10</row>
+      <col>3</col>
+    </text>
+
 
   </group>