Refactor arc drawing

shader/twoD/arc.frag

@@ -1,17 +1,12 @@
 #version 430 core
-in vec4 gColor;
-in float gRadIn;
-in vec2 angles;
-in vec2 dist;
+in vec4 vColor;
+in vec3 vparams;
+
 out vec4 fColor;
 
 void main()
 {
-  float sa = angles.x;
-  vec2 sv = vec2 (-sin(sa), cos(sa));
-  float ea = angles.y;
-  vec2 ev = vec2 (-sin(ea), cos(ea));
-  float d = (dist.x * dist.x) + (dist.y * dist.y);
-  if (d > 1 || d < gRadIn || dot(sv, dist) < 0 || dot(ev, dist) > 0) {discard;}
-  fColor = gColor;
+  float d = dot(vec2(vparams.xy),vec2(vparams.xy));
+  if ( d > 1 || d < vparams.z ) {discard;}
+  fColor = vColor;
 }