Improve ellipses

shader/ellipse.vert

@@ -1,9 +1,7 @@
 #version 430 core
 layout (location = 0) in vec3 position;
 layout (location = 1) in vec4 col;
-layout (location = 2) in float rad;
 out vec4 vCol;
-out float vRad;
 
 uniform vec2 winSize;
 uniform float zoom;
@@ -14,6 +12,5 @@ uniform mat4 worldMat;
 void main()
 {
   gl_Position = worldMat * vec4(position,1);
-  vRad = rad;
   vCol = col;
 }