From b50af8ff4713fa1c8e6e939742b18a534d7fb1a1 Mon Sep 17 00:00:00 2001
From: Thorsten Renk <thorsten@science-and-fiction.org>
Date: Mon, 17 Apr 2017 10:30:49 +0300
Subject: [PATCH] Bugfix and noise seed option for ALS thrust flame shader

---
 Effects/thrust-flame.eff     | 6 ++++++
 Shaders/thrustflame-ALS.frag | 7 ++++---
 2 files changed, 10 insertions(+), 3 deletions(-)

diff --git a/Effects/thrust-flame.eff b/Effects/thrust-flame.eff
index be854b8f3..c5897ccce 100644
--- a/Effects/thrust-flame.eff
+++ b/Effects/thrust-flame.eff
@@ -24,6 +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>
+    <random_seed type="float">0.0</random_seed>
     <deflection_coeff type="float">0.0</deflection_coeff>
     <use_shocks type="int">1</use_shocks>
     <use_noise type="int">1</use_noise>
@@ -132,6 +133,11 @@
         <type>float</type>
         <value><use>noise_scale</use></value>
       </uniform>
+     <uniform>
+        <name>random_seed</name>
+        <type>float</type>
+        <value><use>random_seed</use></value>
+      </uniform>
       <uniform>
         <name>flame_color_low_r</name>
         <type>float</type>
diff --git a/Shaders/thrustflame-ALS.frag b/Shaders/thrustflame-ALS.frag
index f2179dd2b..9fedd6921 100644
--- a/Shaders/thrustflame-ALS.frag
+++ b/Shaders/thrustflame-ALS.frag
@@ -14,6 +14,7 @@ uniform float shock_frequency;
 uniform float noise_strength;
 uniform float noise_scale;
 uniform float deflection_coeff;
+uniform float random_seed;
 
 uniform float flame_color_low_r;
 uniform float flame_color_low_g;
@@ -65,7 +66,7 @@ if (d_rad > radius) {return 0.0;}
 
 if (use_noise ==1)
 	{
-	noise = Noise2D(vec2(pos.x - osg_SimulationTime * 30.0 , d_rad), noise_scale);
+	noise = Noise2D(vec2(pos.x - osg_SimulationTime * 30.0 + random_seed , d_rad), noise_scale);
 	}
 
 density *= (1.0 - smoothstep(0.125, radius, d_rad)) * (1.0 - noise_strength + noise_strength* noise);
@@ -73,7 +74,7 @@ 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(0.25*flame_radius_fraction, 0.5*flame_radius_fraction, 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)) * (1.0 + 0.5 * base_flame_density);
 	}
 
 
@@ -133,7 +134,7 @@ vec3 flame_color_low = vec3 (flame_color_low_r, flame_color_low_g, flame_color_l
 vec3 flame_color_high = vec3 (flame_color_high_r, flame_color_high_g, flame_color_high_b);
 
 vec3 color = mix(flame_color_low, flame_color_high, density2);
-color = mix(color, vec3(0.8, 1.0, 1.0), density1);
+color = mix(color, vec3(base_flame_r, base_flame_g, base_flame_b), density1);
 
 vec4 finalColor = vec4 (color.rgb, density);