Python and Pygame to make a platform game, second part… collitions, physics, maps.
In the second part of this tutorial to make a platform based on the dafluffypotato work, we will do this:
The video explanation
The initializing and the variables for movements
pygame.init()
clock = pygame.time.Clock()
pygame.display.set_caption('Game')
WINDOW_SIZE = (600, 400)
# This will be the Surface where we will blit everything
display = pygame.Surface((300, 200))
# Then we will scale (every frame) the display onto the screen
screen = pygame.display.set_mode(WINDOW_SIZE, 0, 32)
moving_right = False
moving_left = False
# For the pygame.transform.flip(player_img, 1, 0)
stay_right = True
momentum = 0
air_timer = 0
The variables holding the map and its tiles
game_map1 = """
<---->xxxx<----xxxx
ox<----ooo-------oo
o------ooo--------o
o--->xxoo-----xxxxo
o------ooxxx<-----o
oxx<---oo-------xxo
o------oo---------o
o--->xxooxxxxxxx<-o
o------oo---------o
oxxxxxxoo-xxxxxxxxo
ooooooooo----------
ooooooooooooooooooo
""".splitlines()
game_map = [list(lst) for lst in game_map1]
tl = {}
tl["o"] = dirt_img = pygame.image.load('dirt.png')
tl["x"] = grass_img = pygame.image.load('grass.png')
tl["<"] = grassr = pygame.image.load('grassr.png')
tl[">"] = grassr = pygame.image.load('grassl.png')
The player image converted to transparent and its rect object
player_img = pygame.image.load('player.png').convert()
player_img.set_colorkey((255, 255, 255))
player_rect = pygame.Rect(100, 100, 5, 13)
This returns a list of the tiles colliding with the player
def collision_test(rect, tiles):
"Returns the Rect of the tile with which the player collides"
hit_list = []
for tile in tiles:
if rect.colliderect(tile):
hit_list.append(tile)
return hit_list
This returns the player rect and where the collision is (up, left…)
def move(rect, movement, tiles):
collision_types = {
'top': False, 'bottom': False, 'right': False, 'left': False}
rect.x += movement[0]
hit_list = collision_test(rect, tiles)
for tile in hit_list:
if movement[0] > 0:
rect.right = tile.left
collision_types['right'] = True
elif movement[0] < 0:
rect.left = tile.right
collision_types['left'] = True
rect.y += movement[1]
hit_list = collision_test(rect, tiles)
for tile in hit_list:
if movement[1] > 0:
rect.bottom = tile.top
collision_types['bottom'] = True
elif movement[1] < 0:
rect.top = tile.bottom
collision_types['top'] = True
return rect, collision_types
The while loop that draw the map of tiles
loop = 1
while loop:
# CLEAR THE SCREEN
display.fill((146, 244, 255))
# Tiles are blitted ==========================
tile_rects = []
y = 0
for line_of_symbols in game_map:
x = 0
for symbol in line_of_symbols:
if symbol in tl:
# draw the symbol for image
display.blit(
tl[symbol], (x * 16, y * 16))
# draw a rectangle for every symbol except for the empty one
if symbol != "-":
tile_rects.append(pygame.Rect(x * 16, y * 16, 16, 16))
x += 1
y += 1
# ================================================
The movement detection to draw the player (in the while loop)
# MOVEMENT OF THE PLAYER
player_movement = [0, 0]
if moving_right:
player_movement[0] += 2
if moving_left:
player_movement[0] -= 2
player_movement[1] += momentum
momentum += 0.3
if momentum > 3:
momentum = 3
player_rect, collisions = move(player_rect, player_movement, tile_rects)
if collisions['bottom']:
air_timer = 0
momentum = 0
else:
air_timer += 1
# Flip the player image when goes to the left
if stay_right:
display.blit(
player_img, (player_rect.x, player_rect.y))
else:
display.blit(
pygame.transform.flip(player_img, 1, 0),
(player_rect.x, player_rect.y))
The key command to move the player
for event in pygame.event.get():
if event.type == QUIT:
loop = 0
if event.type == KEYDOWN:
if event.key == K_RIGHT:
moving_right = True
stay_right = True
if event.key == K_LEFT:
moving_left = True
stay_right = False
if event.key == K_SPACE:
if air_timer < 6:
momentum = -5
if event.type == KEYUP:
if event.key == K_RIGHT:
moving_right = False
if event.key == K_LEFT:
moving_left = False
Scaling the display on the screen (and quitting)
screen.blit(pygame.transform.scale(display, (600, 400)), (0, 0))
pygame.display.update()
clock.tick(60)
pygame.quit()
and now …
The whole code
import pygame
import sys
from pygame.locals import *
pygame.init()
clock = pygame.time.Clock()
pygame.display.set_caption('Game')
WINDOW_SIZE = (600, 400)
# This will be the Surface where we will blit everything
display = pygame.Surface((300, 200))
# Then we will scale (every frame) the display onto the screen
screen = pygame.display.set_mode(WINDOW_SIZE, 0, 32)
moving_right = False
moving_left = False
# For the pygame.transform.flip(player_img, 1, 0)
stay_right = True
momentum = 0
air_timer = 0
game_map1 = """
<---->xxxx<----xxxx
ox<----ooo-------oo
o------ooo--------o
o--->xxoo-----xxxxo
o------ooxxx<-----o
oxx<---oo-------xxo
o------oo---------o
o--->xxooxxxxxxx<-o
o------oo---------o
oxxxxxxoo-xxxxxxxxo
ooooooooo----------
ooooooooooooooooooo
""".splitlines()
game_map = [list(lst) for lst in game_map1]
tl = {}
tl["o"] = dirt_img = pygame.image.load('dirt.png')
tl["x"] = grass_img = pygame.image.load('grass.png')
tl["<"] = grassr = pygame.image.load('grassr.png')
tl[">"] = grassr = pygame.image.load('grassl.png')
player_img = pygame.image.load('player.png').convert()
player_img.set_colorkey((255, 255, 255))
player_rect = pygame.Rect(100, 100, 5, 13)
def collision_test(rect, tiles):
"Returns the Rect of the tile with which the player collides"
hit_list = []
for tile in tiles:
if rect.colliderect(tile):
hit_list.append(tile)
return hit_list
def move(rect, movement, tiles):
collision_types = {
'top': False, 'bottom': False, 'right': False, 'left': False}
rect.x += movement[0]
hit_list = collision_test(rect, tiles)
for tile in hit_list:
if movement[0] > 0:
rect.right = tile.left
collision_types['right'] = True
elif movement[0] < 0:
rect.left = tile.right
collision_types['left'] = True
rect.y += movement[1]
hit_list = collision_test(rect, tiles)
for tile in hit_list:
if movement[1] > 0:
rect.bottom = tile.top
collision_types['bottom'] = True
elif movement[1] < 0:
rect.top = tile.bottom
collision_types['top'] = True
return rect, collision_types
loop = 1
while loop:
# CLEAR THE SCREEN
display.fill((146, 244, 255))
# Tiles are blitted ==========================
tile_rects = []
y = 0
for line_of_symbols in game_map:
x = 0
for symbol in line_of_symbols:
if symbol in tl:
# draw the symbol for image
display.blit(
tl[symbol], (x * 16, y * 16))
# draw a rectangle for every symbol except for the empty one
if symbol != "-":
tile_rects.append(pygame.Rect(x * 16, y * 16, 16, 16))
x += 1
y += 1
# ================================================
# MOVEMENT OF THE PLAYER
player_movement = [0, 0]
if moving_right:
player_movement[0] += 2
if moving_left:
player_movement[0] -= 2
player_movement[1] += momentum
momentum += 0.3
if momentum > 3:
momentum = 3
player_rect, collisions = move(player_rect, player_movement, tile_rects)
if collisions['bottom']:
air_timer = 0
momentum = 0
else:
air_timer += 1
# Flip the player image when goes to the left
if stay_right:
display.blit(
player_img, (player_rect.x, player_rect.y))
else:
display.blit(
pygame.transform.flip(player_img, 1, 0),
(player_rect.x, player_rect.y))
for event in pygame.event.get():
if event.type == QUIT:
loop = 0
if event.type == KEYDOWN:
if event.key == K_RIGHT:
moving_right = True
stay_right = True
if event.key == K_LEFT:
moving_left = True
stay_right = False
if event.key == K_SPACE:
if air_timer < 6:
momentum = -5
if event.type == KEYUP:
if event.key == K_RIGHT:
moving_right = False
if event.key == K_LEFT:
moving_left = False
screen.blit(pygame.transform.scale(display, (600, 400)), (0, 0))
pygame.display.update()
clock.tick(60)
pygame.quit()
Pygame's Platform Game
