Add completed circle shader, add incomplete arc shader

shader/arc.vert

@@ -0,0 +1,13 @@
+#version 430 core
+layout (location = 0) in vec3 position;
+layout (location = 1) in vec4 color;
+layout (location = 2) in float rad;
+out vec4 vColor;
+out float vRad;
+void main()
+{
+  gl_Position = vec4(position,1);
+  //gl_Position = vec4(0,0,0,1);
+  vColor = color;
+  vRad = rad;
+}