From 3de372f83fb55821d9fa76c12217f457e853d8fb Mon Sep 17 00:00:00 2001
From: Stefan Dresselhaus <sdressel@techfak.uni-bielefeld.de>
Date: Mon, 21 Apr 2014 15:55:22 +0200
Subject: [PATCH] added fog.

---
 shaders/map/fragment.shader | 12 ++++++++++++
 shaders/map/tessEval.shader |  2 ++
 src/Render/Render.hs        |  2 +-
 3 files changed, 15 insertions(+), 1 deletion(-)

diff --git a/shaders/map/fragment.shader b/shaders/map/fragment.shader
index 285afcc..01649cb 100644
--- a/shaders/map/fragment.shader
+++ b/shaders/map/fragment.shader
@@ -94,18 +94,29 @@ float snoise(vec3 v)
                                 dot(p2,x2), dot(p3,x3) ) );
   }
 
+float fog(float dist) {
+    dist = max(0,dist - 50);
+    dist = dist * 0.05;
+    dist = dist;
+    return 1-exp(-dist);
+}
 
 smooth in vec3 teNormal;
 smooth in vec3 tePosition;
+smooth in float fogDist;
 smooth in float gmix;
 in vec4 teColor;
 
 out vec4 fgColor;
 
 uniform mat4 ViewMatrix;
+uniform mat4 ProjectionMatrix;
 
 void main(void)
 {
+    //fog color
+    vec4 fogColor = vec4(0.6,0.7,0.8,1.0);
+
     //heliospheric lighting
     vec4 light = vec4(1.0,1.0,1.0,1.0);
     vec4 dark  = vec4(0.0,0.0,0.0,1.0);
@@ -142,4 +153,5 @@ void main(void)
     vec4 Color = texColor;
 
     fgColor = Color * mix(dark, light, a);
+    fgColor = mix(fgColor,fogColor,fog(fogDist));
 }
\ No newline at end of file
diff --git a/shaders/map/tessEval.shader b/shaders/map/tessEval.shader
index 09f6483..11feec1 100644
--- a/shaders/map/tessEval.shader
+++ b/shaders/map/tessEval.shader
@@ -9,6 +9,7 @@ in vec3 tcNormal[];
 out vec4 teColor;
 smooth out vec3 tePosition;
 smooth out vec3 teNormal;
+out float fogDist;
 smooth out float gmix; //mixture of gravel
 //out vec3 tePatchDistance;
 //constant projection matrix
@@ -38,6 +39,7 @@ void main()
     float standout = i0+i1+i2;
     tePosition = tePosition+tessNormal*standout;
     gl_Position = ProjectionMatrix * ViewMatrix * vec4(tePosition, 1);
+    fogDist = gl_Position.z;
 
     //COLOR-BLENDING
     vec4 c0 = sqrt(gl_TessCoord.x) * tcColor[0];
diff --git a/src/Render/Render.hs b/src/Render/Render.hs
index dd8678a..1171d60 100644
--- a/src/Render/Render.hs
+++ b/src/Render/Render.hs
@@ -172,7 +172,7 @@ initHud = do
 
 initRendering :: IO ()
 initRendering = do
-        clearColor $= Color4 0 0 0 0
+        clearColor $= Color4 0.6 0.7 0.8 1
         depthFunc $= Just Less
         glCullFace gl_BACK
         checkError "initRendering"