Now the program manages balls collisions with themselves.

3 files changed, 76 insertions, 8 deletions

diff --git a/ball.py b/ball.py
index 01a0fdf..d4d1d46 100644
--- a/ball.py
+++ b/ball.py
@@ -22,7 +22,8 @@ class Ball(object):
         velocity : current direction of move => A tuple of 2 floats (x,y)
         """
         info = pygame.display.Info()
-        self._SCREEN_WIDTH, self._SCREEN_HEIGTH = info.current_w, info.current_h        
+        self._SCREEN_WIDTH = info.current_w
+        self._SCREEN_HEIGHT = info.current_h        
         self._txt_font = txt_font
         self._txt_color = txt_color
         self._bg_color = bg_color
@@ -102,7 +103,15 @@ class Ball(object):
             self._center = (self._center[0] + self._velocity[0],
                             self._center[1] + self._velocity[1])
         elif (self._center[1] < radius
-             or self._center[1] > self._SCREEN_HEIGTH - radius):
+             or self._center[1] > self._SCREEN_HEIGHT - radius):
             self._velocity = (self._velocity[0], -self._velocity[1])
             self._center = (self._center[0] + self._velocity[0],
-                            self._center[1] + self._velocity[1])
\ No newline at end of file
+                            self._center[1] + self._velocity[1])
+                            
+    def oppose_velocity_and_move(self):
+        """
+        Alters the velocity, by multiplying each of its values
+        by -1, then move it from one step (calling move).
+        """
+        self._velocity = (self._velocity[0] * -1,
+                          self._velocity[1] * -1)
\ No newline at end of file
diff --git a/balls_collision.py b/balls_collision.py
new file mode 100644
index 0000000..eed62ab
--- /dev/null
+++ b/balls_collision.py
@@ -0,0 +1,41 @@
+# -*- coding: utf-8 -*-
+"""
+Manages balls collisions
+Created on Fri Sep 20 19:57:22 2013
+
+@author: laurent-bernabe
+"""
+
+from math import sqrt
+
+def are_colliding_balls(ball_1, ball_2):
+    """
+    Says whether two balls collides.
+    ball_1 : ball to test => Ball
+    ball_2 : ball to test => Ball
+    => Boolean
+    """
+    b1_x, b1_y = ball_1.get_center()
+    b2_x, b2_y = ball_2.get_center()
+    x_dist = abs(b1_x - b2_x)
+    y_dist = abs(b1_y - b2_y)
+    b1_radius = ball_1.get_diameter() / 2
+    b2_radius = ball_2.get_diameter() / 2
+    centers_dist = sqrt(x_dist**2 + y_dist**2)
+    return centers_dist <= (b1_radius + b2_radius)
+    
+def manage_colliding_balls(balls_list):
+    """
+    Detects all colliding balls couples of balls_list,
+    and, for each colliding balls couple, alter both ball
+    velocity and make a move for both.
+    balls_list : list of balls => List of Ball
+    """
+    for fst_ball_index in range(len(balls_list[:-1])):
+        fst_ball = balls_list[fst_ball_index]        
+        inner_range = range(fst_ball_index + 1, len(balls_list))
+        for snd_ball_index in inner_range:
+            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
diff --git a/main.py b/main.py
index 13b5cf8..1761878 100644
--- a/main.py
+++ b/main.py
@@ -13,6 +13,7 @@ from pygame.locals import QUIT
 from ball import *
 from operation import *
 from elements_painter import *
+import balls_collision
 
 
 def main():
@@ -31,20 +32,37 @@ def main():
     font = PangoFont(family='Helvetica', size=16, bold=True)
     BLACK = (0, 0, 0)
     BLUE = (0, 0, 255)
-    the_ball = Ball(font, BLACK, BLUE, Operation(1000, 3000, OPER_MUL),
-                    (2, 1.2))
-    the_ball.move_to((140, 170))
+    YELLOW = (255, 255, 0)
+    RED = (255, 0, 0)
+    GREEN = (0, 255, 0)
+    the_balls = [Ball(font, BLACK, BLUE, 
+                      Operation(1000, 3000, OPER_MUL), (2, 1.2)),
+                 Ball(font, BLACK, YELLOW, 
+                      Operation(120, 45, OPER_SUB), (1.6,-0.4)),
+                 Ball(font, BLACK, RED, 
+                      Operation(9, 3, OPER_DIV), (-0.8, 1.6)),
+                 Ball(font, BLACK, GREEN,
+                      Operation(120, 240, OPER_ADD), (1.7, -1.2))]
+                
+
+    the_balls[0].move_to((140, 170))
+    the_balls[1].move_to((400, 300))
+    the_balls[2].move_to((200, 80))
+    the_balls[3].move_to((330, 70))
     
     while True:
         screen.fill(BACKGROUND)
-        paint_ball(the_ball, screen)
+        for ball in the_balls:
+            paint_ball(ball, screen)
         for event in pygame.event.get():
             if event.type == QUIT:
                 pygame.quit()
                 exit()
         pygame.display.update()
         clock.tick(FPS)
-        the_ball.move()
+        for ball in the_balls:
+            ball.move()
+        balls_collision.manage_colliding_balls(the_balls)
 
 if __name__ == "__main__":
     main()