Render bezier curves using distance fields

shader/bezierQuad.frag

@@ -1,32 +1,18 @@
 #version 430 core
-in vec4 gColor;
-in vec3 gBoundingBox;
-in vec2 box2;
-in float wStart;
-in float wEnd;
-// the width is calculated along the line a-c
-// this should instead be along the lines a-b (for start width)
-// and b-c (for end width)
+in vec4 vColor;
+in vec2 boxOut;
+in vec2 boxIn;
 
 out vec4 fColor;
 
-float x = gBoundingBox.x;
-float y = gBoundingBox.y;
-float z = gBoundingBox.z;
-
-float f (float a, float b)
-{   
-    float c = 1 / (1 - 2*b) ;
-    return c * (a - 0.5) + 0.5 ;
-}
 void main()
 {
   //float d = x - y - 1 + 2* sqrt(y);
-  float d = sqrt(x) + sqrt(y) - 1;
+  float d = sqrt(boxOut.x) + sqrt(boxOut.y) - 1;
 //  float e = sqrt(f(x,wStart)) + sqrt(f(y,wEnd)) - 1.0;
-  float e = sqrt(box2.x) + sqrt(box2.y) - 1.0;
+  float e = sqrt(boxIn.x) + sqrt(boxIn.y) - 1.0;
 //  if ( d < 0 || e > 0) { discard; }
-  fColor = gColor;
+  fColor = vColor;
 //  if ( d < 0 || e > 0) { fColor = vec4(0,0,1,1); }
   if ( d < 0 || e > 0) { fColor = vec4(0,0,1,1); }
 }

shader/bezierQuad.vert

@@ -1,10 +1,10 @@
 #version 430 core
 layout (location = 0) in vec3 position;
 layout (location = 1) in vec4 color;
-layout (location = 2) in vec3 radVec;
+layout (location = 2) in vec4 boxes;
 out vec4 vColor;
-out vec2 vPosOff;
-out float vRadMag;
+out vec2 boxOut;
+out vec2 boxIn;
 
 uniform vec2 winSize;
 uniform float zoom;
@@ -16,6 +16,6 @@ void main()
 {
   gl_Position = worldMat * vec4(position.xyz,1);
   vColor  = color;
-  vPosOff = ( worldMat * vec4(radVec.xy,0,1) ).xy ;
-  vRadMag = radVec.z ;
+  boxOut = boxes.xy ;
+  boxIn = boxes.zw ;
 }