def draw():
"""Frame drawing function.
Wipes the screen, blits all game sprites then screen sprites
(and calling update on them), then scales the screen and updates
the main display.
"""
# wipe game screen
# to be replaced with background drawing
game_screen.fill((0, 0, 0))
# draw each map layer
for map_layer in map:
map_layer.draw(game_screen)
# update and draw each game sprite
for sprite in game_sprites:
if sprite.is_particle:
# check collision on only certain particles
# i.e. projectiles
if hasattr(sprite, "collide_sprite"):
if sprite.collide_map() \
or any(sprite.collide_sprite(s) for s in game_sprites):
# the particle will then be removed and freed
remove_game_sprites(sprite)
# update all sprites, then draw
sprite.update()
sprite.draw(game_screen)
# update and draw each screen sprite
# these are rendered after all game sprites because
# they need to always show over other sprites.
for sprite in screen_sprites:
sprite.update()
sprite.draw(game_screen)
# blit the low-res screen onto the main screen and scale it
screen.blit(pygame.transform.scale(game_screen, options.dimensions()), (0, 0))
# update the display
pygame.display.update()
def init():
"""Initialise the screen and game screen, and set default options.
"""
try:
flags = 0
if options.fullscreen():
flags |= FULLSCREEN
# flags |= RESIZABLE
# initialise the screen
global screen
screen = pygame.display.set_mode(options.dimensions(), flags)
# initialise the game_screen
global game_screen
game_screen = pygame.Surface(options.game_dimensions())
pygame.mouse.set_visible(False)
pygame.display.update()
except pygame.error as msg:
raise pygame.error("Failed to initialize render engine {0}".format(str(msg)))
