Create world matrix uniform

shader/arc.vert

@@ -9,27 +9,11 @@ uniform vec2 winSize;
 uniform float zoom;
 uniform vec2 translation;
 uniform float rotation;
-
-vec2 tran(vec2 v)
-{
-  return (v -  translation);
-}
-vec2 rot(vec2 v)
-{
-  return vec2 ( v.x * cos(-rotation) - v.y * sin(-rotation)
-              , v.x * sin(-rotation) + v.y * cos(-rotation)
-              );
-}
-vec2 scal(vec2 v)
-{
-  return vec2 ( 2 * v.x * zoom / winSize.x
-              , 2 * v.y * zoom / winSize.y
-          );
-}
+uniform mat4 worldMat;
 
 void main()
 {
-  gl_Position = vec4(scal(rot(tran(position.xy))),position.z,1);
+  gl_Position = worldMat * vec4(position.xyz,1);
   vColor = color;
   vparams = saEaRadWdth;
 }