Add barrel distortion shader

shader/texture/barrel.frag

@@ -0,0 +1,18 @@
+#version 430 core
+in vec2 cenPos;
+in vec2 texPos;
+in vec2 texDist;
+in float factor;
+out vec4 fColor;
+layout (binding = 1) uniform sampler2D screenTexture;
+float f ( float x) {
+ return max (1, 1 / (2 * x + 0.5)) ;
+// return min (1, x) ;
+}
+void main()
+{
+    vec4 tColor = vec4(texture(screenTexture , texPos) );
+    float t = distance(cenPos,texDist);
+    fColor = vec4(tColor.xy,t,tColor.w);
+      //, cenPos + f(distance(cenPos,texDist)) * (texPos - cenPos))) ;
+}

shader/texture/barrel.geom

@@ -0,0 +1,48 @@
+#version 430 core
+layout (points) in;
+layout (triangle_strip, max_vertices = 4) out;
+in vec2 vRad1[];
+in vec2 vRad2[];
+in float vFactor[];
+out vec2 cenPos;
+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)
+    { return vec2 
+        //(x,y);
+        (dot(rad1-cpos,vec2(x,y)-cpos)
+        ,dot(rad2-cpos,vec2(x,y)-cpos)
+        ); 
+    }
+void main() {
+  float factor = vFactor[0];
+  cenPos = cpos;
+  texPos = vec2(1,1);
+  //texDist = g(root,root);
+  texDist = vec2(root,root);
+  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);
+  gl_Position = vec4 (1,-1,0,1);
+  EmitVertex();
+  texPos = vec2(0,1);
+  //texDist = g(-root,root);
+  texDist = vec2(-root,root);
+  gl_Position = vec4 (-1,1,0,1);
+  EmitVertex();
+  texPos = vec2(0,0);
+  //texDist = g(-root,-root);
+  texDist = vec2(-root,-root);
+  gl_Position = vec4 (-1,-1,0,1);
+  EmitVertex();
+  EndPrimitive();
+}

shader/texture/barrel.vert

@@ -0,0 +1,17 @@
+#version 430 core
+layout (location = 0) in vec2 pos;
+layout (location = 1) in vec2 rad1;
+layout (location = 2) in vec2 rad2;
+layout (location = 3) in float factor;
+layout (std140, binding = 0) uniform TheMat { mat4 theMat; } ;
+out vec2 vRad1;
+out vec2 vRad2;
+out float vFactor;
+void main()
+{
+  gl_Position = theMat * vec4(pos,0,1);
+  //gl_Position = vec4(1,1,0,1);
+  vRad1 = (theMat * vec4(rad1,0,1)).xy;
+  vRad2 = (theMat * vec4(rad2,0,1)).xy;
+  vFactor = factor;
+}

shader/texture/colorBlur.frag

@@ -0,0 +1,57 @@
+#version 430 core
+in vec2 vTexPos;
+out vec4 fColor;
+
+uniform vec2 winSize;
+uniform sampler2D screenTexture;
+
+const float hOff = 2.0 / 600;
+const float vOff = 2.0 / 600;
+const float frac = 1.0 / 9;
+const vec2 off[9] = vec2[]
+    ( vec2( vOff,hOff )
+    , vec2( vOff,0.0 )
+    , vec2( vOff,-hOff )
+    , vec2( 0.0,hOff )
+    , vec2( 0.0,0.0 )
+    , vec2( 0.0,-hOff )
+    , vec2( -vOff,hOff )
+    , vec2( -vOff,0.0 )
+    , vec2( -vOff,-hOff )
+    );
+const vec2 fiveOff[5] = vec2[]
+    ( vec2( vOff,0.0 )
+    , vec2( 0.0,hOff )
+    , vec2( 0.0,0.0 )
+    , vec2( 0.0,-hOff )
+    , vec2( -vOff,0.0 )
+    );
+vec4 combinef (vec4 ac, vec4 bc)
+//{ return vec4 (max(ac.x,bc.x),max(ac.y,bc.y),max(ac.z,bc.z),ac.w + bc.w -
+//        ac.w*bc.w);
+//{ return vec4 (max(ac.x,bc.x),max(ac.y,bc.y),max(ac.z,bc.z),ac.w + bc.w);
+{ return vec4 (ac.rgb + bc.rgb * bc.a , ac.a + bc.a );
+}
+void main()
+{
+    vec4 sampleTex[9];
+    for(int i=0; i<9; i++)
+    {
+        sampleTex[i] = vec4(texture(screenTexture, vTexPos + off[i]));
+    }
+    vec4 col = vec4(0,0,0,0);
+    for (int i = 0; i < 9; i++)
+        col = combinef(col,sampleTex[i]);
+        //col += sampleTex[i] * frac;
+    float alph = 0.0;
+    for (int i = 0; i < 9; i++)
+        alph += sampleTex[i].a;
+    alph = min(sampleTex[4].a, alph/9.0);
+        //
+    //fColor = col;
+    fColor = vec4(col.rgb/col.a,alph);
+    //if (col.a == 0.0)
+    //{ fColor = vec4(0,0,0,0); }
+    //else
+    //{ fColor = vec4( col.r/col.a , col.g/col.a , col.b/col.a, col.a/9.0); }
+}

shader/texture/colorBlur.vert

@@ -0,0 +1,9 @@
+#version 430 core
+layout (location = 0) in vec2 pos;
+layout (location = 1) in vec2 texPos;
+out vec2 vTexPos;
+void main()
+{
+  gl_Position = vec4(pos,0,1);
+  vTexPos = texPos;
+}