From 8dea8d1ed9e94085577a835ecd2cbc59060fb366 Mon Sep 17 00:00:00 2001
From: Stefan Dresselhaus <sdressel@techfak.uni-bielefeld.de>
Date: Sun, 11 May 2014 10:52:45 +0200
Subject: [PATCH] refined shaders

- grid is now visible
- grid-points are different colored
- tesselated triangles wont get "gridded".
---
 shaders/map/fragment.shader | 14 +++++++++++++-
 shaders/map/tessEval.shader |  2 ++
 2 files changed, 15 insertions(+), 1 deletion(-)

diff --git a/shaders/map/fragment.shader b/shaders/map/fragment.shader
index ec6ac9f..e211418 100644
--- a/shaders/map/fragment.shader
+++ b/shaders/map/fragment.shader
@@ -106,6 +106,7 @@ smooth in vec3 tePosition;
 smooth in float fogDist;
 smooth in float gmix;
 in vec4 teColor;
+in vec3 tePatchDistance;
 
 out vec4 fgColor;
 
@@ -116,6 +117,10 @@ void main(void)
 {
     //fog color
     vec4 fogColor = vec4(0.6,0.7,0.8,1.0);
+    //grid color
+    vec4 grid = vec4(0.0,0.0,0.0,1.0);
+    //point color
+    vec4 point = vec4(1.0,0.9,0.1,1.0);
 
     //heliospheric lighting
     vec4 light = vec4(1.0,1.0,1.0,1.0);
@@ -154,4 +159,11 @@ void main(void)
 
     fgColor = Color * mix(dark, light, a);
     fgColor = mix(fgColor,fogColor,fog(fogDist));
-}
\ No newline at end of file
+
+    //mix onto tri-borders
+    float mixer = clamp(exp(1.0-50.0*min(tePatchDistance.x,min(tePatchDistance.y,tePatchDistance.z))),0,1);
+    fgColor = mix(fgColor, grid, mixer);
+    
+    mixer = clamp(exp(1.0-50.0*min(tePatchDistance.x+tePatchDistance.y,min(tePatchDistance.x+tePatchDistance.z,tePatchDistance.y+tePatchDistance.z))),0,1);
+    fgColor = mix(fgColor, point, mixer);
+}
diff --git a/shaders/map/tessEval.shader b/shaders/map/tessEval.shader
index 513df69..c4abf04 100644
--- a/shaders/map/tessEval.shader
+++ b/shaders/map/tessEval.shader
@@ -106,6 +106,7 @@ smooth out vec3 tePosition;
 smooth out vec3 teNormal;
 smooth out float fogDist;
 smooth out float gmix; //mixture of gravel
+out vec3 tePatchDistance;
 //out vec3 tePatchDistance;
 //constant projection matrix
 uniform mat4 ProjectionMatrix;
@@ -126,6 +127,7 @@ void main()
     vec3 p1 = gl_TessCoord.y * tcPosition[1];
     vec3 p2 = gl_TessCoord.z * tcPosition[2];
     tePosition = p0 + p1 + p2;
+    tePatchDistance = gl_TessCoord;
 
     //sin(a,b) = length(cross(a,b))
     float i0 = (1-gl_TessCoord.x)*gl_TessCoord.x * length(cross(tcNormal[0],tessNormal));