I am trying to make a simple platformer in pygame, with simulated gravity and collision. I can't make the collision working. On collision with a sprite, the player slowly falls through the sprite and continues falling at normal speed when reached through.
Main.py:
class Game:
def __init__(self):
# initialize pygame library
pg.init()
pg.mixer.init()
# initialize screen
self.screen = pg.display.set_mode((WIDTH, HEIGHT))
pg.display.set_caption(TITLE)
self.clock = pg.time.Clock()
self.font = pg.font.match_font(FONT_NAME)
self.running = True
self.playing = True
def new(self):
# initzialize sprite groups
self.sprites = pg.sprite.Group()
self.objects = pg.sprite.Group()
self.p = Player(self)
self.sprites.add(self.p)
self.g = Ground()
self.sprites.add(self.g)
self.objects.add(self.g)
self.o = Object(100, 350, 100, 20)
self.sprites.add(self.o)
self.objects.add(self.o)
self.collide = False
self.run()
# constant running functions
def run(self):
while self.playing:
self.clock.tick(FPS)
self.events()
self.update()
self.draw()
self.running = False
def events(self):
for event in pg.event.get():
if event.type == pg.QUIT:
self.playing = False
if event.type == pg.KEYDOWN:
if event.key == pg.K_UP:
self.p.jump()
def update(self):
self.sprites.update()
hits = pg.sprite.spritecollide(self.p, self.objects, False)
if hits:
self.collide = True
if self.p.vel.y >= 0.0:
self.p.x = hits[0].rect.top
print("Collide bottom")
elif self.p.vel.y < 0: self.p.top = hits[0].rect.bottom
elif self.p.vel.x > 0: self.p.rect.right = hits[0].rect.left
elif self.p.vel.x < 0: self.p.rect.left = hits[0].rect.right
self.p.vel.y = 0
#self.p.acc.y = 0
#print(f"Collision with {hits[0].name}")
else:
self.collide = False
def draw(self):
self.screen.fill(BLACK)
self.sprites.draw(self.screen)
self.drawtext(f"X Pos: = {int(self.p.pos.x)}", 15, WHITE, WIDTH - 5, 20, 3)
self.drawtext(f"Y Pos: = {int(self.p.pos.y)}", 15, WHITE, WIDTH - 5, 40, 3)
self.drawtext(f"Y Velocity = {self.p.vel.y}", 15, WHITE, 5, 50, 0)
self.drawtext(f"Y Accelleration = {self.p.acc.y}", 15, WHITE, 5, 70, 0)
self.drawtext(f"Collision: = {self.collide}", 15, WHITE, 5, 200, 0)
#print(self.p.vel.y)
pg.display.flip()
# other functions
def drawtext(self, text, size, color, x, y, align):
font = pg.font.Font(self.font, size)
text_surface = font.render(text, True, color)
text_rect = text_surface.get_rect()
if align == 0:
text_rect.midleft = (x, y)
elif align == 1:
text_rect.midtop = (x, y)
elif align == 2:
text_rect.midbottom = (x, y)
elif align == 3:
text_rect.midright = (x, y)
else:
text_rect.center = (x, y)
self.screen.blit(text_surface, text_rect)
# def checkCollisionY(self):
# hits = pg.sprite.spritecollide(self.p, self.objects, False)
# if hits:
# self.collide = True
# return True
# else:
# self.collide = False
# return False
g = Game()
while g.running:
g.new()
pg.quit()
Sprites.py:
from settings import *
import pygame as pg
vec = pg.math.Vector2
class Player(pg.sprite.Sprite):
def __init__(self, game):
pg.sprite.Sprite.__init__(self)
self.game = game
self.width = 30
self.height = 30
self.image = pg.Surface((self.width, self.height))
self.image.fill(YELLOW)
self.rect = self.image.get_rect()
self.rect.center = vec(150, 100)
self.pos = vec(150, 100)
self.vel = vec(0, 0)
self.acc = vec(0, 0)
def update(self):
self.acc = vec(0, PLAYER_GRAV)
#input
keys = pg.key.get_pressed()
if keys[pg.K_LEFT]:
self.acc.x = -PLAYER_ACC
if keys[pg.K_RIGHT]:
self.acc.x = PLAYER_ACC
self.acc.x += self.vel.x * PLAYER_FRICTION
self.vel += self.acc
self.pos += self.vel + 0.5 * self.acc
print(f"{self.vel.y} + 0.5 * {self.acc.y} = {self.vel.y + 0.5 * self.acc.y}")
self.rect.topleft = self.pos
def jump(self):
hits = pg.sprite.spritecollide(self, self.game.objects, False)
if hits:
self.vel.y = -20
class Object(pg.sprite.Sprite):
def __init__(self, x, y, w, h):
pg.sprite.Sprite.__init__(self)
self.image = pg.Surface((w, h))
self.image.fill((255, 0, 144))
self.name = "Object"
self.rect = self.image.get_rect()
self.rect.x = x
self.rect.y = y
class Ground(pg.sprite.Sprite):
def __init__(self):
pg.sprite.Sprite.__init__(self)
self.name = "Ground"
self.image = pg.image.load("ground.png")
self.rect = self.image.get_rect()
self.rect.x = -100
self.rect.y = 550
Settings.py:
# game settings
TITLE = "My Game"
WIDTH = 480
HEIGHT = 800
FPS = 60
FONT_NAME = 'impact'
#Player properties
PLAYER_ACC = 0.7
PLAYER_FRICTION = -0.12
PLAYER_GRAV = 0.7
# define colors
WHITE = (255, 255, 255)
BLACK = (0, 0, 0)
RED = (255, 0, 0)
GREEN = (0, 255, 0)
BLUE = (0, 0, 255)
YELLOW = (255, 255, 0)
CYAN = (0, 255, 255)
PURPLE = (255, 0, 255)
The important code here is the update() in main.py and update() in sprites.py. Help?
EDIT
hits = pg.sprite.spritecollide(self.p, self.objects, False)
for hit in hits:
self.collide = True
if self.p.vel.x > 0.0:
self.p.rect.right = hit.rect.left
self.p.pos.x = self.p.rect.centerx
self.p.vel.x = 0
elif self.p.vel.x < 0.0:
self.p.rect.left = hit.rect.right
self.p.pos.x = self.p.rect.centerx
self.p.vel.x = 0
self.p.pos.x = self.p.rect.x
else:
self.collide = False
hits = pg.sprite.spritecollide(self.p, self.objects, False)
for hit in hits:
self.collide = True
if self.p.vel.y >= 0.0:
self.p.rect.bottom = hit.rect.top
self.p.pos.y = self.p.rect.centery
self.p.vel.y = 0
elif self.p.vel.y < 0.0:
self.p.rect.top = hit.rect.bottom
self.p.pos.y = self.p.rect.centery
self.p.vel.y = 0
self.p.pos.y = self.p.rect.y
else:
self.collide = False
Your Player class doesn't have x and y attributes but a pos attribute which you need to change after a collision. The rect of the object needs to be updated as well and it's better to do that first and then set the pos.y coordinate to the rect.centery coordinate afterwards.
if self.p.vel.y >= 0.0:
self.p.rect.bottom = hits[0].rect.top
self.p.pos.y = self.p.rect.centery
self.p.vel.y = 0
Do the same for the other directions.
Also, the horizontal and vertical movement should be handled separately, otherwise you'll see odd jumps for example from the side to the top of a platform. Take a look at the first part of this platformer example.
And in the jump method you need to move the rect down by 1 pixel so that it's able to collide with the platform sprites.
def jump(self):
self.rect.y += 1
# ...
Here's a complete, runnable example:
import pygame as pg
# game settings
TITLE = "My Game"
WIDTH = 480
HEIGHT = 800
FPS = 60
FONT_NAME = 'impact'
#Player properties
PLAYER_ACC = 0.7
PLAYER_FRICTION = -0.12
PLAYER_GRAV = 0.7
# define colors
WHITE = (255, 255, 255)
BLACK = (0, 0, 0)
YELLOW = (255, 255, 0)
vec = pg.math.Vector2
class Player(pg.sprite.Sprite):
def __init__(self, game):
pg.sprite.Sprite.__init__(self)
self.game = game
self.image = pg.Surface((30, 30))
self.image.fill(YELLOW)
self.rect = self.image.get_rect(center=(150, 100))
self.pos = vec(150, 100)
self.vel = vec(0, 0)
self.acc = vec(0, 0)
self.objects = game.objects
def update(self):
self.acc = vec(0, PLAYER_GRAV)
#input
keys = pg.key.get_pressed()
if keys[pg.K_LEFT]:
self.acc.x = -PLAYER_ACC
if keys[pg.K_RIGHT]:
self.acc.x = PLAYER_ACC
self.acc.x += self.vel.x * PLAYER_FRICTION
self.vel += self.acc
# Move along the x-axis first.
self.pos.x += self.vel.x + 0.5 * self.acc.x
# print(f"{self.vel.y} + 0.5 * {self.acc.y} = {self.vel.y + 0.5 * self.acc.y}")
self.rect.centerx = self.pos.x
# Check if the sprite collides with a platform.
hits = pg.sprite.spritecollide(self, self.objects, False)
if hits:
# Reset the x position.
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
# Move along the y-axis.
self.pos.y += self.vel.y + 0.5 * self.acc.y
self.rect.centery = self.pos.y
# Check if the sprite collides with a platform.
hits = pg.sprite.spritecollide(self, self.objects, False)
if hits:
# Reset the y position.
if self.vel.y >= 0.0:
self.rect.bottom = hits[0].rect.top
self.pos.y = self.rect.centery
self.vel.y = 0
elif self.vel.y < 0:
self.rect.top = hits[0].rect.bottom
self.pos.y = self.rect.centery
self.vel.y = 0
def jump(self):
self.rect.y += 1 # Move it down to check if it collides with a platform.
hits = pg.sprite.spritecollide(self, self.game.objects, False)
if hits:
self.vel.y = -20
self.rect.y -= 1 # Move it up again after the collision check.
class Object(pg.sprite.Sprite):
def __init__(self, x, y, w, h):
pg.sprite.Sprite.__init__(self)
self.image = pg.Surface((w, h))
self.image.fill((255, 0, 144))
self.name = "Object"
self.rect = self.image.get_rect()
self.rect.x = x
self.rect.y = y
class Ground(pg.sprite.Sprite):
def __init__(self):
pg.sprite.Sprite.__init__(self)
self.name = "Ground"
self.image = pg.Surface((500, 300))
self.image.fill((90, 30, 30))
self.rect = self.image.get_rect()
self.rect.x = -100
self.rect.y = 550
class Game:
def __init__(self):
pg.init()
pg.mixer.init()
self.screen = pg.display.set_mode((WIDTH, HEIGHT))
pg.display.set_caption(TITLE)
self.clock = pg.time.Clock()
self.font = pg.font.match_font(FONT_NAME)
self.running = True
self.playing = True
def new(self):
self.sprites = pg.sprite.Group()
self.objects = pg.sprite.Group()
self.p = Player(self)
self.sprites.add(self.p)
self.g = Ground()
self.sprites.add(self.g)
self.objects.add(self.g)
rects = [(100, 350, 100, 20), (50, 380, 100, 20),
(200, 450, 100, 100)]
for x, y, w, h in rects:
obj = Object(x, y, w, h)
self.sprites.add(obj)
self.objects.add(obj)
self.collide = False
self.run()
def run(self):
while self.playing:
self.clock.tick(FPS)
self.events()
self.update()
self.draw()
self.running = False
def events(self):
for event in pg.event.get():
if event.type == pg.QUIT:
self.playing = False
if event.type == pg.KEYDOWN:
if event.key == pg.K_UP:
self.p.jump()
def update(self):
self.sprites.update()
def draw(self):
self.screen.fill(BLACK)
self.sprites.draw(self.screen)
pg.display.flip()
g = Game()
while g.running:
g.new()
pg.quit()