From 4e3efa239c9bcb5dd26b4ad9a4d43d4d6a266e6f Mon Sep 17 00:00:00 2001
From: Matthias Schiffer <matthias@gamezock.de>
Date: Fri, 18 Dec 2009 13:31:07 +0100
Subject: Use multi-pass rendering with seperate ambient and light shaders

---
 shader/light.frag | 41 +++++++++++++++++++++++++++++++++++++++++
 1 file changed, 41 insertions(+)
 create mode 100644 shader/light.frag

(limited to 'shader/light.frag')

diff --git a/shader/light.frag b/shader/light.frag
new file mode 100644
index 0000000..c3cdbfb
--- /dev/null
+++ b/shader/light.frag
@@ -0,0 +1,41 @@
+uniform sampler2D tex;
+
+varying vec4 diffuse, ambient;
+varying vec3 normal, pos;
+
+
+void main() {
+  vec3 n, l, refl, eye;
+  float NdotL, RdotE;
+  vec4 color, specularColor;
+  float dist, att, specularFactor;
+  
+  n = normalize(normal);
+  
+  l = gl_LightSource[0].position.xyz - pos;
+  
+  dist = length(l);
+  l /= dist;
+  
+  /* compute the dot product between normal and normalized lightdir */
+  NdotL = max(dot(n, l), 0.0);
+
+  if (NdotL > 0.0) {
+    att = 1.0 / (gl_LightSource[0].constantAttenuation +
+        gl_LightSource[0].linearAttenuation * dist +
+        gl_LightSource[0].quadraticAttenuation * dist * dist);
+    color = att * (diffuse * NdotL + ambient);
+    
+    refl = normalize(reflect(-l, n));
+    eye = normalize(-pos);
+    
+    RdotE = max(dot(refl, eye), 0.0);
+    specularFactor = att * pow(RdotE, gl_FrontMaterial.shininess);
+    specularColor = specularFactor * gl_FrontMaterial.specular * gl_LightSource[0].specular;
+    
+    gl_FragColor = color * texture2D(tex, gl_TexCoord[0].st) + specularColor;
+  }
+  else {
+    gl_FragColor = vec4(0, 0, 0, 1);
+  }
+}
-- 
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