notes.txt

Jim Brooks
http://www.jimbrooks.org/python
2004/08, 2009/08
Notes about Python implementation of Space Invaders.

- The game is over if you let the space invaders successfully land,
  regardless of remaining lives.

- Developed using Python, PyGame, SDL.

- Demonstrating how easy programming in Python and PyGame is,
  this program was up-and-running in only 2 days!

- Animation is driven by a timer and based on a list of objects
  (player, aliens, missiles).

- Aliens are divided into "columns".
  Only the alien at the bottom of column can fire.

- Alien and missile objects will temporarily become invalid
  (.valid = False) and will be perodically pruned.
  The player object stays valid.
  Invalid objects should be excluded from rendering and
  collision detection.

- An sprite object's .hit is decremented every tick.
  When an object is struck, .hit is assigned a value > 0.
  The object becomes dead at the moment .hit transitions from 0 to 1.

- The first for event line works OK on Mandrake 8.1,
  but timer events simply stop after about 2 seconds on Redhat 8.
    #for event in pygame.event.get():
    for event in [ pygame.event.wait() ]:

- Apple Mac:
  This warning happens but program will run anyway:
  python[643] *** _NSAutoreleaseNoPool(): Object 0x1146400 of class NSCFString autoreleased with no pool in place - just leaking