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How to make collision detection work when you have simulated gravity for your game?

I am creating a platform game using pygame, in my game I have simulated gravity and platforms that can be jumped on but I'm having trouble getting the collision detection to work correctly. By collision detection I mean when my character sprite jumps I want him to bounce off of the bottom and sides of the platform that will be above him. Now my character sprite jumps through the platform and lands on top of it.
My code is as follows:
My main class:
import pygame
import random
from settings import *
from sprites import *
from camera import *
from os import path
class Game:
def __init__(self):
pygame.init() # initialises pygame
pygame.mixer.init()
self.screen = pygame.display.set_mode((WIDTH, HEIGHT)) # sets the width and height of the pygame window
pygame.display.set_caption(TITLE)
self.clock = pygame.time.Clock()
self.running = True
self.font_name = pygame.font.match_font(FONT_NAME)
self.load_data()
def load_data(self):
pass
def new(self):
self.all_sprites = pygame.sprite.Group()
self.platforms = pygame.sprite.Group()
self.player = Player(self)
self.all_sprites.add(self.player)
for plat in PLATFORM_LIST:
p = Platform(*plat)
self.all_sprites.add(p)
self.platforms.add(p)
self.camera = Camera(WIDTH, HEIGHT) # creates the camera with WIDTH and HEIGHT of the screen
self.run()
def run(self): # Game Loop - runs the game
self.playing = True
while self.playing:
self.clock.tick(FPS)
self.events()
self.update()
self.draw()
def update(self): # Game loop - update
self.all_sprites.update()
# collision with a platform
if self.player.vel.y > 0:
hits = pygame.sprite.spritecollide(self.player, self.platforms, False) # returns a list of platform sprites that hit the player
if hits:
self.player.pos.y = hits[0].rect.top
self.player.vel.y = 0
# screen moves with player
self.camera.update(self.player) # is the camera that tracks players movement
def events(self): # Game loop - events
for event in pygame.event.get():
if event.type == pygame.QUIT:
if self.playing:
self.playing = False
self.running = False
if event.type == pygame.KEYDOWN:
if event.key == pygame.K_SPACE:
self.player.jump()
def draw(self): # Game loop - draw
self.screen.fill(RED)
#self.all_sprites.draw(self.screen)
for sprite in self.all_sprites:
self.screen.blit(sprite.image, self.camera.apply(sprite)) # loops through the all_sprites group and blit's each sprite onto the screen
pygame.display.flip()
def start_screen(self):
pass
def game_over_screen(self):
pass
def wait_for_key(self):
pass
def draw_text(self,text, size, colour, x, y):
pass
g = Game()
g.start_screen()
while g.running:
g.new()
g.game_over_screen()
pygame.quit()
my sprite classes:
# will hold the sprite classes
import pygame
from settings import *
import random
vec = pygame.math.Vector2
class Player(pygame.sprite.Sprite):
def __init__(self, game):
pygame.sprite.Sprite.__init__(self)
self.game = game
self.image = pygame.Surface((30, 40))
self.image.fill(BLUE)
self.rect = self.image.get_rect()
self.rect.center = (WIDTH / 2, HEIGHT / 2)
self.pos = vec(WIDTH / 2, HEIGHT / 2)
self.vel = vec(0, 0)
self.acc = vec(0, 0)
def jump(self):
# jump only if on a platform
self.rect.x += 1
hits = pygame.sprite.spritecollide(self, self.game.platforms, False)
self.rect.x -= 1
if hits:
self.vel.y = -20
def update(self):
self.acc = vec(0, PLAYER_GRAV)
keys = pygame.key.get_pressed()
if keys[pygame.K_LEFT]:
self.acc.x = -PLAYER_ACC
if keys[pygame.K_RIGHT]:
self.acc.x = PLAYER_ACC
# apply friction
self.acc.x += self.vel.x * PLAYER_FRICTION
# equations of motion
self.vel += self.acc
self.pos += self.vel + 0.5 * self.acc
# stop from running of the left side of the screen
if self.pos.x < 0:
self.pos.x = 0
self.rect.midbottom = self.pos
class Platform(pygame.sprite.Sprite):
def __init__(self, x, y, width, height):
pygame.sprite.Sprite.__init__(self)
self.image = pygame.Surface((width, height))
self.image.fill(GREEN)
self.rect = self.image.get_rect()
self.rect.x = x
self.rect.y = y
camera class
import pygame
from settings import *
# A camera that keeps track of an offset that will be, how far we want to draw the screen which will include all objects on the screen. We are just shifting the drawing of our screen according to the offset. Camera needs to do two things, apply the offset and then update the movement of where the player is on the screen.
class Camera:
def __init__(self, width, height): # we will need to tell the camera how wide and high we want it to be
self.camera = pygame.Rect(0, 0, width, height) # is the rectangle we set to keep track of the screen/be the camera
self.width = width
self.height = height
def apply(self, entity): # method to apply the offset to the screen, by shifting the screen according to the movement of the entity within the camera screen
return entity.rect.move(self.camera.topleft)
def update(self, target): # method to update where the player/target has moved to, updates are done according to last known position of the target
# as the target moves the camera moves in the opposite direction of the target and stays within the center of the screen
x = -target.rect.x + int(WIDTH/2) # left to right
y = -target.rect.y + int(HEIGHT/2) # up and down
# limit scrolling to map size, keeps the 'camera' from going over the edges
x = min(0, x) # left
y = min(0, y) # top
y = max(-(self.height - HEIGHT), y) # bottom
self.camera = pygame.Rect(x, y, self.width, self.height) # adjusts the camera's rectangle with the new x and y
settings module:
# Game options/settings
TITLE = 'Platformer'
WIDTH = 900
HEIGHT = 500
FPS = 60
FONT_NAME = 'arial'
HS_FILE = 'highscore.txt'
SPRITESHEET = 'spritesheet_jumper.png'
# Game colours
WHITE = (255, 255, 255)
BLACK = (0, 0, 0)
RED = (255, 0, 0)
GREEN = (0, 255, 0)
BLUE = (0, 0, 255)
YELLOW = (255, 255, 0)
# Starting Platforms:
PLATFORM_LIST = [(0, HEIGHT - 50, WIDTH, 50), (WIDTH / 2, HEIGHT * 1 / 2, 200, 30), (WIDTH + 150, HEIGHT - 50, WIDTH, 50)]
# player properties
PLAYER_ACC = 0.5
PLAYER_FRICTION = -0.12
PLAYER_GRAV = 0.8
P.S. added all my code for anyone that may need to see it.

Your question says "when you have simulated gravity" but i don't understand how that would affect the bouncing. The answer below should work with your applied gravity so i don't think gravity will be an issue. So first, to bounce, we will need to know which side of the player is colliding with a particular side of the platform. For this the following functions can be used.
#Checks if right side of the player is colliding with left side of platform
def rightCheck(rect1, rect2):
if rect1.x + rect1.width > rect2.x:
if (rect1.y > rect2.y and rect1.y < rect2.y + rect2.height) or (rect1.y + rect1.height < rect2.y + rect2.height and rect1.y + rect1.height> rect2.y):
if rect1.x < rect2.x:
return True
return False
#Checks if bottom side of the player is colliding with top side of platform
def botCheck(rect1, rect2):
if rect1.y + rect1.height > rect2.y:
if (rect1.x > rect2.x and rect1.x < rect2.x + rect2.width) or (rect1.x + rect1.width > rect2.x and rect1.x + rect1.width < rect2.x + rect2.width):
if rect1.y < rect2.y:
return True
return False
# NOTICE they take pygame.Rect as arguments
For your game you are probably going to need one for left of the player and right side of the platform well, but i don't have it since i copied these from my game. I am sure you can write one yourself :). So, moving on. The code below shows how right side of the player colliding with left side of the platform can be implemented. So you can do this with all the sides. Also, bounce function is probably the only one you are interested in, others i has to put there to make it work.
import pygame
win = pygame.display
D = win.set_mode((1200, 600))
def rightCheck(rect1, rect2):
if rect1.x + rect1.width > rect2.x:
if (rect1.y > rect2.y and rect1.y < rect2.y + rect2.height) or (rect1.y + rect1.height < rect2.y + rect2.height and rect1.y + rect1.height> rect2.y):
if rect1.x < rect2.x:
return True
return False
class Player:
def __init__(self, ):
self.pos = [10, 10]
self.surf = pygame.Surface((50, 50)).convert()
self.energy = 10 #how much the player bounces to the left by
self.trigger = False #Triggers the left push if it is true
self.rightCheck = rightCheck # this is the function to check collision
self.rvel = 0.5 # This is the movement speed
def move(self):
key = pygame.key.get_pressed()
if key[pygame.K_RIGHT]:
self.pos[0] += self.rvel
if key[pygame.K_LEFT]:
self.pos[0] -= 0.5
if key[pygame.K_UP]:
self.pos[1] -= 0.5
if key[pygame.K_DOWN]:
self.pos[1] += 0.5
def draw(self):
D.blit(self.surf, (self.pos[0], self.pos[1]))
def bounce(self, platRect):
selfRect = pygame.Rect(self.pos[0], self.pos[1], 50, 50)
if self.rightCheck(selfRect, platRect):
self.trigger = True
self.rvel = 0
else:
self.rvel = 0.5
if self.trigger:
self.pos[0] -= self.energy*0.1
self.rvel = 0.1
self.energy -= 0.05
if self.energy <= 0:
self.trigger = False
else:
self.energy = 10
p = Player()
while True:
pygame.event.get()
D.fill((255, 255, 255))
platformRect = pygame.Rect(300, 150, 600, 200)
pygame.draw.rect(D, (0, 0, 0), platformRect)
p.bounce(platformRect)
p.move()
p.draw()
p.bounce(platformRect)
win.flip()
It basically just checks if they are colliding and if they are pushes the player a little to the left.

How can I get my collisions to work with the sides of a platform in my platform?

I am currently creating a platform game using python pygame but have gotten stuck with the collisions. I have gotten the bottom and top collisions to work with my character sprite but as of now my character won't stop or bounce off the sides of a platform. when doing collisions, I am using the method sprite.spritecollide() which I would like to do in the same way if anyone can help. I have done the collision check correctly but my code for handling the collision I cannot seem to get it done correctly. My code where I do the collision detection is as follows in the main.py in the game update function:
import pygame
import random
from settings import *
from sprites import *
from camera import *
from os import path
class Game:
def __init__(self):
pygame.init() # initialises pygame
pygame.mixer.init()
self.screen = pygame.display.set_mode((WIDTH, HEIGHT)) # sets the width and height of the pygame window
pygame.display.set_caption(TITLE)
self.clock = pygame.time.Clock()
self.running = True
self.font_name = pygame.font.match_font(FONT_NAME)
self.load_data()
def load_data(self):
pass
def new(self):
self.all_sprites = pygame.sprite.Group()
self.platforms = pygame.sprite.Group()
self.player = Player(self)
self.all_sprites.add(self.player)
for plat in PLATFORM_LIST:
p = Platform(*plat)
self.all_sprites.add(p)
self.platforms.add(p)
self.camera = Camera(WIDTH, HEIGHT) # creates the camera with WIDTH and HEIGHT of the screen
self.run()
def run(self): # Game Loop - runs the game
self.playing = True
while self.playing:
self.clock.tick(FPS)
self.events()
self.update()
self.draw()
def update(self): # Game loop - update
self.all_sprites.update()
# collision with top of platform
if self.player.vel.y > 0:
hits = pygame.sprite.spritecollide(self.player, self.platforms, False) # returns a list of platform sprites that hit the player
if hits:
self.player.pos.y = hits[0].rect.top
self.player.vel.y = 0
# collision with the bottom of a platform
if self.player.vel.y < 0:
hits = pygame.sprite.spritecollide(self.player, self.platforms, False)
if hits:
self.player.top = hits[0].rect.bottom
self.player.vel.y = -self.player.vel.y
# collision with the right side of a platform (moving left), here is the code for the right side of the platform
if self.player.acc.x < 0:
hits = pygame.sprite.spritecollide(self.player, self.platforms, False)
if hits:
self.player.left = hits[0].rect.right
self.player.acc.x = 0
# screen moves with player
self.camera.update(self.player) # is the camera that tracks players movement
def events(self): # Game loop - events
for event in pygame.event.get():
if event.type == pygame.QUIT:
if self.playing:
self.playing = False
self.running = False
if event.type == pygame.KEYDOWN:
if event.key == pygame.K_SPACE:
self.player.jump()
def draw(self): # Game loop - draw
self.screen.fill(RED)
#self.all_sprites.draw(self.screen)
for sprite in self.all_sprites:
self.screen.blit(sprite.image, self.camera.apply(sprite)) # loops through the all_sprites group and blit's each sprite onto the screen
pygame.display.flip()
def start_screen(self):
pass
def game_over_screen(self):
pass
def wait_for_key(self):
pass
def draw_text(self,text, size, colour, x, y):
pass
g = Game()
g.start_screen()
while g.running:
g.new()
g.game_over_screen()
pygame.quit()
I have so far only tried doing collisions for the right side of the platforms, once I've done one side I can replicate for the other side.
P.S. if you need more of my code I will add it to the question if asked to.
EDIT
sprites.py
# will hold the sprite classes
import pygame
from settings import *
import random
vec = pygame.math.Vector2
class Player(pygame.sprite.Sprite):
def __init__(self, game):
pygame.sprite.Sprite.__init__(self)
self.game = game
self.image = pygame.Surface((30, 40))
self.image.fill(BLUE)
self.rect = self.image.get_rect()
self.rect.center = (WIDTH / 2, HEIGHT / 2)
self.pos = vec(WIDTH / 2, HEIGHT / 2)
self.vel = vec(0, 0)
self.acc = vec(0, 0)
def jump(self):
# jump only if on a platform
self.rect.x += 1
hits = pygame.sprite.spritecollide(self, self.game.platforms, False)
self.rect.x -= 1
if hits:
self.vel.y = -20
def update(self):
self.acc = vec(0, PLAYER_GRAV)
keys = pygame.key.get_pressed()
if keys[pygame.K_LEFT]:
self.acc.x = -PLAYER_ACC
if keys[pygame.K_RIGHT]:
self.acc.x = PLAYER_ACC
# apply friction
self.acc.x += self.vel.x * PLAYER_FRICTION
# equations of motion
self.vel += self.acc
self.pos += self.vel + 0.5 * self.acc
# stop from running of the left side of the screen
if self.pos.x < 0:
self.pos.x = 0
self.rect.midbottom = self.pos
class Platform(pygame.sprite.Sprite):
def __init__(self, x, y, width, height):
pygame.sprite.Sprite.__init__(self)
self.image = pygame.Surface((width, height))
self.image.fill(GREEN)
self.rect = self.image.get_rect()
self.rect.x = x
self.rect.y = y
camera.py
import pygame
from settings import *
# A camera that keeps track of an offset that will be, how far we want to draw the screen which will include all objects on the screen. We are just shifting the drawing of our screen according to the offset. Camera needs to do two things, apply the offset and then update the movement of where the player is on the screen.
class Camera:
def __init__(self, width, height): # we will need to tell the camera how wide and high we want it to be
self.camera = pygame.Rect(0, 0, width, height) # is the rectangle we set to keep track of the screen/be the camera
self.width = width
self.height = height
def apply(self, entity): # method to apply the offset to the screen, by shifting the screen according to the movement of the entity within the camera screen
return entity.rect.move(self.camera.topleft)
def update(self, target): # method to update where the player/target has moved to, updates are done according to last known position of the target
# as the target moves the camera moves in the opposite direction of the target and stays within the center of the screen
x = -target.rect.x + int(WIDTH/2) # left to right
y = -target.rect.y + int(HEIGHT/2) # up and down
# limit scrolling to map size, keeps the 'camera' from going over the edges
x = min(0, x) # left
y = min(0, y) # top
y = max(-(self.height - HEIGHT), y) # bottom
self.camera = pygame.Rect(x, y, self.width, self.height) # adjusts the camera's rectangle with the new x and y
settings.py
# Game options/settings
TITLE = 'Platformer'
WIDTH = 900
HEIGHT = 500
FPS = 60
FONT_NAME = 'arial'
HS_FILE = 'highscore.txt'
SPRITESHEET = 'spritesheet_jumper.png'
# Game colours
WHITE = (255, 255, 255)
BLACK = (0, 0, 0)
RED = (255, 0, 0)
GREEN = (0, 255, 0)
BLUE = (0, 0, 255)
YELLOW = (255, 255, 0)
# Starting Platforms:
PLATFORM_LIST = [(0, HEIGHT - 50, WIDTH, 50), (WIDTH / 2, HEIGHT * 1 / 2, 200, 30), (WIDTH + 150, HEIGHT - 50, WIDTH, 50), (WIDTH / 2, HEIGHT * 4 / 5, 200, 30)]
# player properties
PLAYER_ACC = 0.5
PLAYER_FRICTION = -0.12
PLAYER_GRAV = 0.8

I can't test your code but usually problem is that spritecollide doesn't inform if you collide on x or y or both.
When you move x and y at once and check collision then you don't know if you collided on x or y or both. If you collided only on y and you will check vel.x and move player then you get wrong result. The same if you collided only on x and you will check vel.y and move player then you get also wrong result.
You have to do it separatelly:
first move only x, check collisions and check only vel.x,
next move only y, check collisions again and check only vel.y,
Something like this:
def update(self):
#self.all_sprites.update()
# collision with top and bottom of platform
# update only y
self.player.pos.y += self.player.vel.y + 0.5 * self.player.acc.y
hits = pygame.sprite.spritecollide(self.player, self.platforms, False)
if hits:
if self.player.vel.y > 0:
self.player.pos.y = hits[0].rect.top
self.player.vel.y = 0
elif self.player.vel.y < 0:
self.player.top = hits[0].rect.bottom
self.player.vel.y = -self.player.vel.y
# collision with left and right of platform
# update only x
self.player.pos.x += self.player.vel.x + 0.5 * self.player.acc.x
hits = pygame.sprite.spritecollide(self.player, self.platforms, False)
if hits:
if self.player.acc.x < 0:
self.player.left = hits[0].rect.right
self.player.acc.x = 0
elif self.player.acc.x > 0:
self.player.right = hits[0].rect.left
self.player.acc.x = 0
You should see working example in platform examples on page Program Arcade Games With Python And Pygame
EDIT:
Full code
main.py
#import random
#from os import path
import pygame
from settings import *
from sprites import *
from camera import *
class Game:
def __init__(self):
# initialises pygame
pygame.init()
#pygame.mixer.init() # `pygame.init()` should aready runs `pygame.mixer.init()`
# sets the width and height of the pygame window
self.screen = pygame.display.set_mode((WIDTH, HEIGHT))
pygame.display.set_caption(TITLE)
self.font_name = pygame.font.match_font(FONT_NAME)
self.load_data()
# main loop elements
self.clock = pygame.time.Clock()
self.running = True
def load_data(self):
pass
def new(self):
"""Run game"""
self.reset()
self.run()
def reset(self):
"""Reset data"""
self.all_sprites = pygame.sprite.Group()
self.platforms = pygame.sprite.Group()
self.player = Player(self)
self.all_sprites.add(self.player)
for plat in PLATFORM_LIST:
p = Platform(*plat)
self.all_sprites.add(p)
self.platforms.add(p)
# creates the camera with WIDTH and HEIGHT of the screen
self.camera = Camera(WIDTH, HEIGHT)
def run(self):
"""Game Loop - runs the game"""
self.playing = True
while self.playing:
self.clock.tick(FPS)
self.events()
self.update()
self.draw()
def update(self):
"""Game loop - update"""
self.all_sprites.update()
# screen moves with player
self.camera.update(self.player) # is the camera that tracks players movement
def events(self):
"""Game loop - events"""
for event in pygame.event.get():
if event.type == pygame.QUIT:
if self.playing:
self.playing = False
self.running = False
if event.type == pygame.KEYDOWN:
# reset game but not exit
if event.key == pygame.K_ESCAPE:
if self.playing:
self.playing = False
# send event(s) to sprite(s)
self.player.events(event)
def draw(self):
"""Game loop - draw"""
self.screen.fill(RED)
# loops through the all_sprites group and blit's each sprite onto the screen
for sprite in self.all_sprites:
sprite.draw(self.screen, self.camera)
pygame.display.flip()
def start_screen(self):
pass
def game_over_screen(self):
pass
def wait_for_key(self):
pass
def draw_text(self,text, size, colour, x, y):
pass
# --- main ---
g = Game()
g.start_screen()
while g.running:
g.new()
g.game_over_screen()
#g.exit_screen()
pygame.quit()
sprites.py
# will hold the sprite classes
import random
import pygame
from settings import *
vec = pygame.math.Vector2
class BaseSprite(pygame.sprite.Sprite):
"""Base class with functions for all sprites"""
def draw(self, screen, camera):
screen.blit(self.image, camera.apply(self))
class Player(BaseSprite):
def __init__(self, game):
#pygame.sprite.Sprite.__init__(self)
super().__init__()
self.game = game
self.image = pygame.Surface((30, 40))
self.image.fill(BLUE)
self.pos = vec(WIDTH / 2, HEIGHT / 2)
self.vel = vec(0, 0)
self.acc = vec(0, 0)
self.rect = self.image.get_rect()
self.rect.center = self.pos
self.on_ground = True
def jump(self):
if self.on_ground:
self.vel.y = -20
self.on_ground = False
def events(self, event):
if event.type == pygame.KEYDOWN:
if event.key == pygame.K_SPACE:
self.jump()
def update(self):
self.acc = vec(0, PLAYER_GRAV)
keys = pygame.key.get_pressed()
if keys[pygame.K_LEFT]:
self.acc.x = -PLAYER_ACC
if keys[pygame.K_RIGHT]:
self.acc.x = PLAYER_ACC
# apply friction
self.acc.x += self.vel.x * PLAYER_FRICTION
# equations of motion
self.vel += self.acc
# --- horizontal collision ---
self.pos.x += self.vel.x + 0.5 * self.acc.x
self.rect.centerx = self.pos.x
# stop from running of the left side of the screen
if self.rect.left < 0:
self.rect.left = 0
self.pos.x = self.rect.centerx
hits = pygame.sprite.spritecollide(self, self.game.platforms, False)
if hits:
if self.vel.x > 0:
self.rect.right = hits[0].rect.left
self.pos.x = self.rect.centerx
self.vel.x = 0
elif self.vel.x < 0:
self.rect.left = hits[0].rect.right
self.pos.x = self.rect.centerx
self.vel.x = 0
# --- vertical collision ---
self.pos.y += self.vel.y + 0.5 * self.acc.y
self.rect.centery = self.pos.y
# game over when left screen
if self.rect.top > HEIGHT:
self.game.playing = False
hits = pygame.sprite.spritecollide(self, self.game.platforms, False)
if hits:
if self.vel.y > 0:
self.rect.bottom = hits[0].rect.top
self.pos.y = self.rect.centery
self.vel.y = 0
self.on_ground = True
elif self.vel.y < 0:
self.rect.top = hits[0].rect.bottom
self.pos.y = self.rect.centery
self.vel.y = 0
class Platform(BaseSprite):
def __init__(self, x, y, width, height, color):
#pygame.sprite.Sprite.__init__(self)
super().__init__()
self.image = pygame.Surface((width, height))
self.image.fill(color)
#self.rect = self.image.get_rect()
#self.rect.x = x
#self.rect.y = y
# shorter
self.rect = self.image.get_rect(x=x, y=y)
camera.py
without changes
settings.py
I added few platforms
# Game options/settings
TITLE = 'Platformer'
WIDTH = 900
HEIGHT = 500
FPS = 60
FONT_NAME = 'arial'
HS_FILE = 'highscore.txt'
SPRITESHEET = 'spritesheet_jumper.png'
# Game colours
WHITE = (255, 255, 255)
BLACK = (0, 0, 0)
RED = (255, 0, 0)
GREEN = (0, 255, 0)
BLUE = (0, 0, 255)
YELLOW = (255, 255, 0)
# Starting Platforms:
PLATFORM_LIST = [
# grounds
(0, HEIGHT - 50, WIDTH, 50, GREEN),
(WIDTH + 150, HEIGHT - 50, WIDTH, 50, GREEN),
# platforms
(WIDTH / 2, HEIGHT * 1 / 2, 200, 30, YELLOW),
(WIDTH / 2, HEIGHT * 4 / 5, 200, 30, YELLOW),
# walls
(WIDTH - 30, HEIGHT - 250, 30, 200, WHITE),
(WIDTH + 150, HEIGHT - 250, 30, 200, WHITE),
]
# player properties
PLAYER_ACC = 0.5
PLAYER_FRICTION = -0.12
PLAYER_GRAV = 0.8
I was thinging to moves some code to class Screen and then I would use this class to create GameScreen, StartScreen, GameOverScreen, etc.

OOP pygame movement issues

I am just getting started with pygame. My Player instances position does not update on the surface even though it's x value is changed accordingly.
'''__main__.py'''
import script
if __name__ == '__main__':
script.setup()
script.update()
-
'''script.py'''
import pygame
from player import Player
from enemy import Enemy
from ball import Ball
def setup():
global window, player, enemy, ball
pygame.init()
pygame.display.set_caption('Pong')
window = pygame.display.set_mode((800, 600))
player = Player(40, window.get_height() / 2 - 100 / 2, 20, 100)
enemy = Enemy(window.get_width() - 40 - 20, window.get_height() / 2 - 100 / 2, 20, 100)
def draw():
player.update()
enemy.update()
pygame.display.update()
player.draw(window)
enemy.draw(window)
def update():
running = True
while running:
for event in pygame.event.get():
if event.type == pygame.QUIT:
running = False
keys = pygame.key.get_pressed()
if keys[pygame.K_UP]:
player.up = True
if keys[pygame.K_DOWN]:
player.down = True
if not keys[pygame.K_UP]:
player.up = False
if not keys[pygame.K_DOWN]:
player.down = False
draw()
pygame.quit()
-
'''player.py'''
import pygame
class Player:
'''Player'''
def __init__(self, x, y, width, height):
self.x = x
self.y = y
self.width = width
self.height = height
self.color = (255, 255, 255)
self.rect = (self.x, self.y, self.width, self.height)
self.vel = 10
self.up = False
self.down = False
def draw(self, surface):
pygame.draw.rect(surface, self.color, self.rect)
def update(self):
if self.up:
self.x -= self.vel
if self.down:
self.x += self.vel
The instance's x value changes when I press up or down, but for some reason it does not get drawn on screen. I have tried moving the draw method and the player.update method but can't seem to get it to work properly.

Look at the Player.draw method. It draws using self.rect.
The problem with your update method is that it never updates self.rect. So self.rect stays the same as after constructor.
Remove self.rect as attribute and replace it with either simple method (Option A) or property (Option B):
class Player:
# Options A:
def get_rect(self):
return (self.x, self.y, self.width, self.height)
# Option B:
#property
def rect(self):
return (self.x, self.y, self.width, self.height)
Or update self.rect inside update method. But I do not recommend that. Having it separately was a reason why you got your no-changing-position-bug in the first place.

How do I break up my PyGame game into separate files?

I am teaching a fortnightly coding class to a group of dozen super bright young enthusiasts. We have already covered OOP and created a text based adventure using OOP.
Now I am planning to teach PyGame and continue using objects, and I am wondering if games could be built in such a way where the code for each object is in a separate file?, this would be really neat and easier to build on.
Well For the code below I tried making separate files for each object. This was only partially successful because the draw method never works quite well, I believe the issue that I cannot have separate files referencing the same pygame screen.
import pygame
import random
import time
# Define some colors
BLACK = (0, 0, 0)
WHITE = (255, 255, 255)
BLUE = (0,0,255)
SCREEN_WIDTH = 700
SCREEN_HEIGHT = 500
pygame.init()
class Paddle:
'''Class to keep players location'''
def __init__(self,x=350, y=480, width =70,height=20):
self.x = x
self.y = y
self.change_x = 0
self.change_y = 0
self.width = width
self.height = height
self.score = 0
def move(self):
self.x += self.change_x
self.y += self.change_y
def draw(self):
pygame.draw.rect(screen, BLUE, [self.x,self.y, self.width, self.height])
def check_collision(self,ball):
if ball.y>460:
if abs(35+ self.x - ball.x) < 30:
self.score += 1
ball.draw(BLUE)
ball.y = 0
ball.x = random.randint(0,650)
ball.change_y = random.randint(2,3+int(self.score/5))
class Ball:
"""Class to keep track of a ball's location and vector."""
def __init__(self,x=350,y=250,size=25):
self.x = x
self.y = y
self.change_x = 0
self.change_y = 0
self.size = size
def move(self):
self.x += self.change_x
self.y += self.change_y
def draw(self,colour = WHITE):
pygame.draw.circle(screen,WHITE, [self.x, self.y], self.size)
# Set the height and width of the screen
size = [SCREEN_WIDTH, SCREEN_HEIGHT]
screen = pygame.display.set_mode(size)
pygame.display.set_caption("Bouncing Balls")
done = False
clock = pygame.time.Clock()
screen.fill(BLACK)
ball = Ball()
player = Paddle()
ball.change_y = 2
ball.draw()
while not done:
screen.fill(BLACK)
# --- Event Processing
for event in pygame.event.get():
if event.type == pygame.QUIT:
done = True
if event.type == pygame.KEYDOWN:
if event.key == pygame.K_SPACE:
pass
if event.key == pygame.K_LEFT:
player.change_x = -5
if event.key == pygame.K_RIGHT:
player.change_x = 5
else:
ball.change_x = 0
player.change_x = 0
if ball.y > 500:
print('YOUR SCORE: ',player.score)
time.sleep(2)
pygame.quit()
#move ball and player and check if they collide
ball.move()
player.move()
player.check_collision(ball)
#draw ball and player
ball.draw()
player.draw()
#render frame
clock.tick(60)
pygame.display.flip()
# Print score and exit
print('YOUR SCORE: ',player.score)
pygame.quit()
When I had separate files this is the error that I got in relation to screen
line 20, in draw
pygame.draw.circle(screen,WHITE, [self.x, self.y], self.size)
NameError: name 'screen' is not defined

Add a surface argument to the draw() methods of the classes Paddle and Ball and draw the object on the surface which is passed to the method:
class Paddle:
# [...]
def draw(self, surface):
pygame.draw.rect(surface, BLUE, [self.x,self.y, self.width, self.height])
class Ball:
# [...]
def draw(self, surface, colour = WHITE):
pygame.draw.circle(surface, colour, [self.x, self.y], self.size)
Now you can draw the objects on any pygame.Surface you want, e.g. screen:
ball.draw(screen)
player.draw(screen)

Building a keyboard controlled game in pygame. I'm getting an indentation error but I dont know why

This is my game so far. I was able to display the Player and make it move with the keyboard. On a separate program I displayed the Enemy class randomly within the range. When I combined the two programs I started getting a bunch of indentation errors. If I fix one, another one pops ups. Please help!
import pygame
import os
import random
black = (0,0,0)
white = (255,255,255)
red = (255, 0, 0)
green = (0, 100, 0)
# This class represents the bar at the bottom that the player controls
class Player(object):
def __init__(self):
self.image = pygame.image.load("player_one.png").convert()
self.image.set_colorkey(white)
self.width = 15
self.height = 15
self.x = 940
self.y = 240
def handle_keys(self):
key = pygame.key.get_pressed()
if key[pygame.K_DOWN]:
if self.y < 470:
self.y += self.height
elif key[pygame.K_UP]:
if self.y > 0:
self.y -= self.height
if key[pygame.K_RIGHT]:
if self.x < 940:
self.x += self.width
elif key[pygame.K_LEFT]:
if self.x > 0:
self.x -= self.width
def draw(self, surface):
surface.blit(self.image, (self.x, self.y))
class Enemy(object):
def __init__(self):
self.image = pygame.image.load(image).convert()
self.image.set_colorkey(white)
image_rect = image.get_rect()
self.rect = self.image.get_rect()
self.rect.centerx = x
self.rect.centery = y
def draw(self, screen):
surface.blit(self.image, self.rect)
def update(self):
self.rect.topleft = random.randint(60, 220+1), random.randint( 0, 475+1)
class Game():
def __init__(self):
pygame.init()
pygame.display.set_caption('Best Football Game Ever!')
self.screen = pygame.display.set_mode((1000, 500))
self.multi_enemies = []
for i in range(1, 4):
enemy = Enemy("enemy_"+str(i)+".png")
enemy.update()
self.multi_enemies.append(enemy)
def run(self):
clock = pygame.time.Clock()
running = True
while running:
for event in pygame.event.get():
if event.type == pygame.QUIT:
running = False
if event.type == pygame.KEYDOWN:
if event.key == pygame.K_ESCAPE:
running = False
for enemy in self.multi_enemies:
enemy.update()
#---updates----
# place for updates
# --- draws ---
for enemy in self.multi_enemies:
enemy.draw(self.screen)
for x in range(60,940,35):
pygame.draw.line(screen, white, [x, 0], [x, 500], 1)
player.handle_keys()
self.screen.fill(green)
pygame.display.flip()
clock.tick(20)
pygame.quit()
Game().run()

You are mixing tabs with spaces for indentation. The only way this "works" is if you have your tabstop set to 8
Since nearly everyone uses 4 spaces for indentation, a tab looks like two levels of indentation, but Python only counts it as one
Here tabs are highlighted in yellow:

Edit-Select All
then go to
Format- Untabify
That should fix your problem