Allow independent distortion of rgb channels

shader/texture/barrel.vert

@@ -1,11 +1,17 @@
 #version 450 core
-struct DataS { vec2 pos; vec2 v1; vec2 v2; vec2 t1; vec2 t2; vec2 t3; };
+struct DataS { vec2 pos; vec2 v1; vec2 v2; 
+    vec2 t1r; vec2 t2r; vec2 t3r; 
+    vec2 t1g; vec2 t2g; vec2 t3g; 
+    vec2 t1b; vec2 t2b; vec2 t3b; 
+};
 layout (std430, binding = 9) readonly buffer Data { DataS data[]; };
 layout (std140, binding = 0) uniform TheMat { mat4 theMat; } ;
 layout (location = 0) uniform int n;
 out vec2 texPos;
 out vec2 distmask[10];
-out vec2 pinch[10];
+out vec2 pinchr[10];
+out vec2 pinchg[10];
+out vec2 pinchb[10];
 const int ks[6] =   
     {0,1,2          //  2--3
     ,2,1,3          //  |  |
@@ -40,19 +46,45 @@ void main()
   vec2 r2 = f(thedata.v2);
   mat2 distT = inverse (mat2(r1,r2));
   distmask[i] = (distT * (cs[k] - off.xy));
-  vec4 pinchx = theMat 
-      * toTransMat(thedata.t3) 
+  vec4 pinchxr = theMat 
+      * toTransMat(thedata.t3r) 
       * toTransMat(thedata.pos)
       * mat4
-        (thedata.t1 , 0, 0
-        ,thedata.t2 , 0, 0
+        (thedata.t1r , 0, 0
+        ,thedata.t2r , 0, 0
         , 0,      0 , 0, 0
         , 0,      0 , 0, 1
         )
       * inverse(toTransMat(thedata.pos))
       * inverse(theMat) 
       * (vec4(cs[k],0,1));
-  pinch[i] = ncToTex(pinchx.xy) - ncToTex(cs[k]);
+  pinchr[i] = ncToTex(pinchxr.xy) - ncToTex(cs[k]);
+  vec4 pinchxg = theMat 
+      * toTransMat(thedata.t3g) 
+      * toTransMat(thedata.pos)
+      * mat4
+        (thedata.t1g , 0, 0
+        ,thedata.t2g , 0, 0
+        , 0,      0 , 0, 0
+        , 0,      0 , 0, 1
+        )
+      * inverse(toTransMat(thedata.pos))
+      * inverse(theMat) 
+      * (vec4(cs[k],0,1));
+  pinchg[i] = ncToTex(pinchxg.xy) - ncToTex(cs[k]);
+  vec4 pinchxb = theMat 
+      * toTransMat(thedata.t3b) 
+      * toTransMat(thedata.pos)
+      * mat4
+        (thedata.t1b , 0, 0
+        ,thedata.t2b , 0, 0
+        , 0,      0 , 0, 0
+        , 0,      0 , 0, 1
+        )
+      * inverse(toTransMat(thedata.pos))
+      * inverse(theMat) 
+      * (vec4(cs[k],0,1));
+  pinchb[i] = ncToTex(pinchxb.xy) - ncToTex(cs[k]);
   }
   texPos = ncToTex(cs[k]);
   gl_Position = vec4 (cs[k],0,1);