Now there is a function in order to automatize the placement of a balls list so that they don't collide each other.

2 files changed, 25 insertions, 5 deletions

diff --git a/balls_collision.py b/balls_collision.py
index eed62ab..0aa8cf5 100644
--- a/balls_collision.py
+++ b/balls_collision.py
@@ -7,6 +7,7 @@ Created on Fri Sep 20 19:57:22 2013
 """
 
 from math import sqrt
+from random import randint
 
 def are_colliding_balls(ball_1, ball_2):
     """
@@ -38,4 +39,26 @@ def manage_colliding_balls(balls_list):
             snd_ball = balls_list[snd_ball_index]
             if (are_colliding_balls(fst_ball, snd_ball)):
                 fst_ball.oppose_velocity_and_move()
-                snd_ball.oppose_velocity_and_move()
\ No newline at end of file
+                snd_ball.oppose_velocity_and_move()
+                
+def place_balls(balls_list, balls_area):
+    """
+    Places all the balls of balls_list, randomly, within balls_area
+    but assuring that balls don't collide each other.
+    balls_list : list of balls => List of Ball
+    balls_area :  space where ball is allowed to be => Tuple of 4 integers (
+        left side x, top side y, right side x, bottom side y)
+    """
+    placed_balls = []
+    for ball in balls_list:
+        while True:
+            ball_x = randint(balls_area[0], balls_area[2] + 1)
+            ball_y = randint(balls_area[1], balls_area[3] + 1)
+            ball.move_to((ball_x, ball_y))
+            collides = False
+            for placed_ball in placed_balls:
+                curr_collision_state = are_colliding_balls(ball, placed_ball)
+                collides = collides or curr_collision_state
+            if not collides:
+                placed_balls.append(ball)                
+                break
diff --git a/main.py b/main.py
index 5ed65d8..8971051 100644
--- a/main.py
+++ b/main.py
@@ -55,10 +55,7 @@ def main():
                       Operation(120, 240, OPER_ADD), balls_area, (1.7, -1.2))]
                 
 
-    the_balls[0].move_to((430, 200))
-    the_balls[1].move_to((400, 360))
-    the_balls[2].move_to((200, 80))
-    the_balls[3].move_to((330, 100))
+    balls_collision.place_balls(the_balls, balls_area)
     
     while True:
         screen.fill(BACKGROUND)