Dodger - Invent Your Own Computer Games with Python - page 379

20 - Dodger
If the player has closed the window while the program is waiting for the player to press a
key, Pygame will generate a QUIT event and we should terminate the program. We will
call our terminate() function here, rather than call pygame.quit() and sys.exit
() themselves.
25. if event.type == KEYDOWN:
26. if event.key == K_ESCAPE: # pressing
escape quits
27. terminate()
28. return
If we receive a KEYDOWN event, then we should first check if it is the Esc key that was
pressed. If we are waiting for the player to press a key, and the player presses the Esc key,
we want to terminate the program. If that wasn't the case, then execution will skip the if-
block on line 27 and go straight to the return statement, which exits the
waitForPlayerToPressKey() function.
If a QUIT or KEYDOWN event is not generated, then this loop will keep looping until it is.
This will freeze the game until the player presses a key or closes the window.
30. def playerHasHitBaddie(playerRect, baddies):
31. for b in baddies:
32. if playerRect.colliderect(b['rect']):
33. return True
34. return False
We will also define a function named playerHasHitBaddie() which will return
True if the player's character has collided with one of the baddies. The baddies
parameter is a list of baddie data structures. These data structures are just dictionaries, so it
is accurate to say that baddies is a list of dictionary objects. Each of these dictionaries
has a 'rect' key, and the value for that key is a Rect object that represents the baddie's
size and location.
playerRect is also a Rect object. Remember that Rect objects have a method
named colliderect() that returns True if the Rect object has collided with the Rect
object that is passed to the method. Otherwise, colliderect() will return False .
We can use this method in our playerHasHitBaddie() function. First we iterate
through each baddie data structure in the baddies list. If any of these baddies collide with
the player's character, then playerHasHitBaddie() will return True . If the code
manages to iterate through all the baddies in the baddies list without colliding with any
of them, we will return False .
36. def drawText(text, font, surface, x, y):