Use multi-pass rendering with seperate ambient and light shaders

shader/ambient.frag

@@ -0,0 +1,8 @@
+uniform sampler2D tex;
+
+varying vec4 ambient;
+
+
+void main() {
+  gl_FragColor = ambient * texture2D(tex, gl_TexCoord[0].st);
+}

shader/ambient.vert

@@ -0,0 +1,8 @@
+varying vec4 ambient;
+
+void main() {
+  ambient = gl_LightModel.ambient * gl_FrontMaterial.ambient;
+  
+  gl_TexCoord[0] = gl_MultiTexCoord0;
+  gl_Position = ftransform();
+}

shader/light.frag

@@ -1,6 +1,6 @@
 uniform sampler2D tex;
 
-varying vec4 diffuse, ambientGlobal, ambient;
+varying vec4 diffuse, ambient;
 varying vec3 normal, pos;
 
 
@@ -10,8 +10,6 @@ void main() {
   vec4 color, specularColor;
   float dist, att, specularFactor;
   
-  color = ambientGlobal;
-  
   n = normalize(normal);
   
   l = gl_LightSource[0].position.xyz - pos;
@@ -26,7 +24,7 @@ void main() {
     att = 1.0 / (gl_LightSource[0].constantAttenuation +
         gl_LightSource[0].linearAttenuation * dist +
         gl_LightSource[0].quadraticAttenuation * dist * dist);
-    color += att * (diffuse * NdotL + ambient);
+    color = att * (diffuse * NdotL + ambient);
     
     refl = normalize(reflect(-l, n));
     eye = normalize(-pos);
@@ -34,10 +32,10 @@ void main() {
     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 {
-    specularColor = vec4(0, 0, 0, 1);
+    gl_FragColor = vec4(0, 0, 0, 1);
   }
-  
-  gl_FragColor = color * texture2D(tex, gl_TexCoord[0].st) + specularColor;
 }

shader/light.vert

@@ -1,4 +1,4 @@
-varying vec4 diffuse, ambientGlobal, ambient;
+varying vec4 diffuse, ambient;
 varying vec3 normal, pos;
 
 
@@ -10,7 +10,6 @@ void main() {
   diffuse = gl_FrontMaterial.diffuse * gl_LightSource[0].diffuse;
   
   ambient = gl_FrontMaterial.ambient * gl_LightSource[0].ambient;
-  ambientGlobal = gl_LightModel.ambient * gl_FrontMaterial.ambient;
   
   gl_TexCoord[0] = gl_MultiTexCoord0;
   gl_Position = ftransform();