Update polygon.h

include/polygon.h

@@ -11,8 +11,6 @@ typedef struct polygon polygon_t;
  * Initialize a polygon object given a list of vertices.
  *
  * @param points the list of vertices that make up the polygon
- * @param initial_position a vector representing the initial center position of
- * the polygon
  * @param initial_velocity a vector representing the initial velocity of the
  * polygon
  * @param rotation_speed the rotation angle of the polygon per unit time
@@ -22,9 +20,9 @@ typedef struct polygon polygon_t;
  * @param blue double value between 0 and 1 representing the blue of the polygon
  * @return a polygon object pointer
  */
-polygon_t *polygon_init(list_t *points, vector_t initial_position,
-                        vector_t initial_velocity, double rotation_speed,
-                        double red, double green, double blue);
+polygon_t *polygon_init(list_t *points, vector_t initial_velocity, 
+                        double rotation_speed, double red, double green,
+                        double blue);
 
 /**
  * Return the list of vectors representing the vertices of the polygon.