further fragment shader optimizations

shaders/step.frag

@@ -27,7 +27,6 @@ uniform float t;
 
 uniform sampler2D texture1; //other state
 uniform sampler2D texture2; //damping
-uniform sampler2D texture3; //unnecessary
 
 //red is position, green is velocity
 
@@ -38,13 +37,14 @@ void main()
         float right = texture(texture1, rightCoordinates).r;
         float up = texture(texture1, upCoordinates).r;
         float down = texture(texture1, downCoordinates).r;
-        float old_center = texture(texture2, textureCoordinates).r
+
+        float damping = texture(texture2, textureCoordinates).r;
 
         //trial optimizations
         vec4 sum = vec4(left,right,up,down);
         const vec4 A = vec4(c1);
         float dp = dot(A,sum);
-        float newred = (dp + c2*onsite.r - onsite.g) * onsite.b;
+        float newred = (dp + c2*onsite.r - onsite.g) * damping;
 
-        FragColor = vec4(newred, onsite.rb, 1.);
+        FragColor = vec4(newred + onsite.b*source, onsite.rb, 1.);
 }