From aec9efe2e4b817f8ce9438deff2c44160e7b3879 Mon Sep 17 00:00:00 2001
From: Thorsten Renk <thorsten.i.renk@jyu.fi>
Date: Sat, 23 May 2015 11:48:14 +0300
Subject: [PATCH] User-controlled bounding box utilization for thruster flame

---
 Effects/thrust-flame.eff     | 13 ++++++++++++-
 Shaders/thrustflame-ALS.frag | 12 ++++++++----
 2 files changed, 20 insertions(+), 5 deletions(-)

diff --git a/Effects/thrust-flame.eff b/Effects/thrust-flame.eff
index 67fe892cd..be854b8f3 100644
--- a/Effects/thrust-flame.eff
+++ b/Effects/thrust-flame.eff
@@ -8,6 +8,7 @@
       	<type>white</type>
     </texture>
 
+    <flame_radius_fraction type="float">0.2</flame_radius_fraction>
     <thrust_collimation type="float">0.1</thrust_collimation>
     <thrust_density type="float">0.5</thrust_density>
     <base_flame_density type="float">1.0</base_flame_density>
@@ -23,6 +24,7 @@
     <base_flame_r type="float">1.0</base_flame_r>
     <base_flame_g type="float">0.8</base_flame_g>
     <base_flame_b type="float">0.3</base_flame_b>
+    <deflection_coeff type="float">0.0</deflection_coeff>
     <use_shocks type="int">1</use_shocks>
     <use_noise type="int">1</use_noise>
     <visibility><use>/environment/ground-visibility-m</use></visibility>
@@ -95,6 +97,11 @@
         <fragment-shader>Shaders/noise.frag</fragment-shader>
       </program>
 
+     <uniform>
+        <name>flame_radius_fraction</name>
+        <type>float</type>
+        <value><use>flame_radius_fraction</use></value>
+      </uniform>
       <uniform>
         <name>thrust_collimation</name>
         <type>float</type>
@@ -170,7 +177,11 @@
         <type>float</type>
         <value><use>base_flame_b</use></value>
       </uniform>
-     
+      <uniform>
+        <name>deflection_coeff</name>
+        <type>float</type>
+        <value><use>deflection_coeff</use></value>
+      </uniform>
 
       <uniform>
         <name>use_shocks</name>
diff --git a/Shaders/thrustflame-ALS.frag b/Shaders/thrustflame-ALS.frag
index 22de204ad..163333072 100644
--- a/Shaders/thrustflame-ALS.frag
+++ b/Shaders/thrustflame-ALS.frag
@@ -7,11 +7,13 @@ varying vec3 viewDir;
 
 uniform float osg_SimulationTime;
 uniform float thrust_collimation;
+uniform float flame_radius_fraction;
 uniform float thrust_density;
 uniform float base_flame_density;
 uniform float shock_frequency;
 uniform float noise_strength;
 uniform float noise_scale;
+uniform float deflection_coeff;
 
 uniform float flame_color_low_r;
 uniform float flame_color_low_g;
@@ -38,7 +40,7 @@ float spherical_smoothstep (in vec3 pos)
 
 float l = length(vec3 (pos.x/2.0, pos.y,pos.z) );
 
-return 10.0 * thrust_density * base_flame_density *  (1.0 - smoothstep(0.1, 0.2, l));
+return 10.0 * thrust_density * base_flame_density *  (1.0 - smoothstep(0.5* flame_radius_fraction, flame_radius_fraction, l));
 
 }
 
@@ -51,12 +53,14 @@ float thrust_flame (in vec3 pos)
 //float noise = Noise3D(vec3(pos.x - osg_SimulationTime * 20.0 , pos.y, pos.z), 0.3);
 float noise = 0.0;
 
-float d_rad = length(pos.yz);
+pos.z +=8.0 * deflection_coeff;
+
+float d_rad = length(pos.yz - vec2 (0.0, deflection_coeff * pos.x * pos.x));
 //float longFade = smoothstep(0.0, 5.0, pos.x) ;
 float longFade = pos.x/5.0;
 
 float density = 1.0 - longFade;
-float radius = 0.2 + thrust_collimation * 1.2 * pow((pos.x+0.1),0.5);
+float radius = flame_radius_fraction + thrust_collimation * 1.0 * pow((pos.x+0.1),0.5);
 
 if (d_rad > radius) {return 0.0;}
 
@@ -71,7 +75,7 @@ density *= (1.0 - smoothstep(0.125, radius, d_rad)) * (1.0 - noise_strength + no
 if (use_shocks == 1)
 	{
 	float shock = sin(pos.x * 10.0 * shock_frequency);
-	density += shock * shock * shock * shock * (1.0 - longFade) * (1.0 - smoothstep(0.05, 0.1, d_rad)) *  (1.0 - smoothstep(0.0, 1.0, thrust_collimation));
+	density += shock * shock * shock * shock * (1.0 - longFade) * (1.0 - smoothstep(0.25*flame_radius_fraction, 0.5*flame_radius_fraction, d_rad)) *  (1.0 - smoothstep(0.0, 1.0, thrust_collimation));
 	}