Working radial distortion

shader/texture/barrel.geom

@@ -3,45 +3,43 @@ layout (points) in;
 layout (triangle_strip, max_vertices = 4) out;
 in vec2 vRad1[];
 in vec2 vRad2[];
+in vec2 vCen[];
 in float vFactor[];
-out vec2 cenPos;
+out vec2 vcpos;
 out vec2 texPos;
 out vec2 texDist;
-out float factor;
-//const float root = 1 / sqrt(2);
-const float root = 1;
-vec2 cpos = gl_in[0].gl_Position.xy;
-vec2 rad1 = vRad1[0];
-vec2 rad2 = vRad2[0];
-vec2 g(float x,float y)
+out float gfactor;
+
+vec2 g(float x,float y, vec2 v, vec2 r1, vec2 r2)
     { return vec2 
-        //(x,y);
-        (dot(rad1-cpos,vec2(x,y)-cpos)
-        ,dot(rad2-cpos,vec2(x,y)-cpos)
+        (dot(normalize(r1-v),vec2(x,y)-v) / length(r1-v)
+        ,dot(normalize(r2-v),vec2(x,y)-v) / length(r2-v)
         ); 
     }
 void main() {
-  float factor = vFactor[0];
-  cenPos = cpos;
+  vec2 cpos = vCen[0];
+  //vcpos = 2*cpos - vec2(1,1);
+  vcpos = cpos;
+  vec2 grad1 = vRad1[0];
+  vec2 grad2 = vRad2[0];
+  gfactor = vFactor[0];
   texPos = vec2(1,1);
-  //texDist = g(root,root);
-  texDist = vec2(root,root);
+  texDist = g(1,1,cpos,grad1,grad2);
   gl_Position = vec4 (1,1,0,1);
-  //gl_Position = vec4 (cenPos,0,1);
   EmitVertex();
   texPos = vec2(1,0);
-  //texDist = g(root,-root);
-  texDist = vec2(root,-root);
+  texPos = vec2(1,-1);
+  texDist = g(1,-1,cpos,grad1,grad2);
   gl_Position = vec4 (1,-1,0,1);
   EmitVertex();
   texPos = vec2(0,1);
-  //texDist = g(-root,root);
-  texDist = vec2(-root,root);
+  texPos = vec2(-1,1);
+  texDist = g(-1,1,cpos,grad1,grad2);
   gl_Position = vec4 (-1,1,0,1);
   EmitVertex();
   texPos = vec2(0,0);
-  //texDist = g(-root,-root);
-  texDist = vec2(-root,-root);
+  texPos = vec2(-1,-1);
+  texDist = g(-1,-1,cpos,grad1,grad2);
   gl_Position = vec4 (-1,-1,0,1);
   EmitVertex();
   EndPrimitive();