Allow for multiple distortions at once

shader/texture/barrel.frag

@@ -1,12 +1,11 @@
 #version 450 core
 in vec2 texPos;
-in vec2 distmask;
-in vec2 pinch;
+in vec2 distmask[2];
+in vec2 pinch[2];
 out vec4 fColor;
 layout (binding = 1) uniform sampler2D screenTexture;
-float x = 1 - min(1, sqrt(distance(distmask,vec2(0,0))));
-float xab = abs(distmask.x);
-float yab = abs(distmask.y);
+float x = 1 - min(1, sqrt(distance(distmask[0],vec2(0,0))));
+//float x = 1 - min(1, dot(distmask,distmask));
 vec3 toYUV (vec3 rgb)
 { return rgb * mat3
     ( 0.299  , 0.587  , 0.114
@@ -23,14 +22,12 @@ vec3 toRGB (vec3 yuv)
 }
 void main()
 {
-    fColor = texture(screenTexture, (texPos + x * pinch));
-    //fColor = texture(screenTexture, (texPos + x*pinch));
-    //fColor = texture(screenTexture, (texPos + x*pinch));
-//    fColor = vec4
-//        ( texture(screenTexture, (texPos + x*pinch)).r
-//        , texture(screenTexture, (texPos + x*(-pinch))).g
-//        , texture(screenTexture, texPos).ba
-//        ) ;
+    float y = 1 - min(1, sqrt(distance(distmask[1],vec2(0,0))));
+    fColor = texture(screenTexture
+            , (texPos + x * pinch[0] 
+                + y * pinch[1]
+                ));
+}
 //    fColor = vec4
 //        ( toRGB(vec3(  toYUV(texture(screenTexture, texPos).rgb).r
 //                , toYUV(texture(screenTexture, (texPos + x*pinch)).rgb).g
@@ -38,4 +35,3 @@ void main()
 //                ) )
 //        , 1
 //        ) ;
-}

shader/texture/barrel.vert

@@ -3,8 +3,8 @@ struct DataS { vec2 pos; vec2 v1; vec2 v2; vec2 t1; vec2 t2; vec2 t3; };
 layout (std430, binding = 9) readonly buffer Data { DataS data[]; };
 layout (std140, binding = 0) uniform TheMat { mat4 theMat; } ;
 out vec2 texPos;
-out vec2 distmask;
-out vec2 pinch;
+out vec2 distmask[2];
+out vec2 pinch[2];
 const int ks[6] =   
     {0,1,2          //  2--3
     ,2,1,3          //  |  |
@@ -31,12 +31,14 @@ mat4 toTransMat (vec2 p)
 void main()
 {
   int k = ks[gl_VertexID];
-  DataS thedata = data[gl_VertexID/6];
-  vec4 off = theMat * vec4(data[gl_VertexID/6].pos, 0,1);
+  for(int i = 0; i < 2; ++i)
+  {
+  vec4 off = theMat * vec4(data[i + gl_VertexID/6].pos, 0,1);
+  DataS thedata = data[i + gl_VertexID/6];
   vec2 r1 = f(thedata.v1);
   vec2 r2 = f(thedata.v2);
   mat2 distT = inverse (mat2(r1,r2));
-  distmask = distT * (cs[k] - off.xy);
+  distmask[i] = (distT * (cs[k] - off.xy));
   vec4 pinchx = theMat 
       * toTransMat(thedata.t3) 
       * toTransMat(thedata.pos)
@@ -49,7 +51,8 @@ void main()
       * inverse(toTransMat(thedata.pos))
       * inverse(theMat) 
       * (vec4(cs[k],0,1));
-  pinch = ncToTex(pinchx.xy) - ncToTex(cs[k]);
+  pinch[i] = ncToTex(pinchx.xy) - ncToTex(cs[k]);
+  }
   texPos = ncToTex(cs[k]);
   gl_Position = vec4 (cs[k],0,1);
 }