I'm trying to find a way to make perfect collision in my platformer game for school. Most of it works but there is a slight problem. When I stand on a platform above ground level and move left or right off of it, the player continues to float in midair at the same height of the platform that I got off of. This can be fixed by jumping and the collision reverts to normal. I am using a state system to track if the player is standing or not by having a folder of possible player states and switching between them. This is set to "Falling" by default because the player starts in midair when the game runs. The code for the game is divided into three separate files below (main.py, obj.py and settings.py). Please tell me how I can fix this glitch.
Main.py
import pygame
import random
from settings import *
from obj import *
pygame.init()
pygame.mixer.init()
pygame.font.init()
pygame.display.set_caption(TITLE)
screen = pygame.display.set_mode([WIDTH,HEIGHT])
clock = pygame.time.Clock()
me = Player()
all_sprites.add(me)
platforms = []
pf = Wall(20,40,500,480, 0)
pf2 = Wall(WIDTH,40, 400,500, 0)
platforms.append(pf)
platforms.append(pf2)
for i in platforms:
wall_sprites.add(i)
running = True
while running:
clock.tick(FPS)
all_sprites.update()
wall_sprites.update()
for event in pygame.event.get():
if event.type == pygame.QUIT:
running = False
screen.fill(GREY)
all_sprites.draw(screen)
wall_sprites.draw(screen)
pygame.display.update()
pygame.quit()
obj.py
import pygame
import math
from settings import *
class Player(pygame.sprite.Sprite):
def __init__(self):
pygame.sprite.Sprite.__init__(self)
self.image = pygame.Surface((40,40))
self.image.fill(BLACK)
self.rect = self.image.get_rect()
self.rect.x = WIDTH / 2
self.rect.y = 70
self.vx = 0
self.vy = 0
self.SW = False # Can you screen wrap?
self.player_states = ["Standing","Falling"]
self.state = self.player_states[1]
def update(self):
self.vx = 0 # X speed set to 0 if no input is received
if self.state == self.player_states[1]:
self.vy += GRAVITY # Gravity only added while falling
else:
self.vy = 0
keys = pygame.key.get_pressed()
if keys[pygame.K_LEFT]:
self.vx = -SPEED
if keys[pygame.K_RIGHT]:
self.vx = SPEED
if keys[pygame.K_SPACE] and self.state == self.player_states[0]:
self.vy -= JUMP_SPEED
self.state = self.player_states[1]
self.rect.left += self.vx # X and Y positions are updated
self.collide(self.vx, 0, wall_sprites) # Collision is checked. Second param is 0 b/c we aren't checking for vertical collision here
self.rect.top += self.vy
self.collide(0, self.vy, wall_sprites)
if self.SW:
if self.rect.left > WIDTH:
self.rect.right = 0
if self.rect.right < 0:
self.rect.left = WIDTH
if self.rect.top > HEIGHT:
self.rect.bottom = 0
if self.rect.bottom < 0:
self.rect.top = HEIGHT
def collide(self, xDif, yDif, platform_list):
for i in platform_list: # Shuffle through list of platforms
if pygame.sprite.collide_rect(self, i): # If there is a collision between the player and a platform...
if xDif > 0: # And our x (horizontal) speed is greater than 0...
self.rect.right = i.rect.left # That means that we are moving right,
if xDif < 0: # So our right bounding box becomes equal to the left bounding box of all platforms and we don't collide
self.rect.left = i.rect.right
if yDif > 0:
self.rect.bottom = i.rect.top
self.state = self.player_states[0]
if yDif < 0:
self.rect.top = i.rect.bottom
class Wall(pygame.sprite.Sprite): # Collision is added for platforms just in case that they are moving. If they move to you, they push you
def __init__(self, width, height, xpos, ypos, speed):
pygame.sprite.Sprite.__init__(self)
self.image = pygame.Surface((width,height))
self.image.fill(BLUE)
self.rect = self.image.get_rect()
self.rect.centerx = xpos
self.rect.centery = ypos
self.speed = speed
def update(self):
self.rect.left += self.speed
self.collide(self.speed, all_sprites) # Collision only for platforms moving left and right. Not up and down yet
def collide(self, xDif, player_list):
for i in player_list:
if pygame.sprite.collide_rect(self, i):
if xDif > 0: # If the platform is moving right... (has positive speed)
i.rect.left += self.speed # Platform pushes player
self.rect.right = i.rect.left # Player sticks to the wall and is pushed
if xDif < 0:
i.rect.right -= self.speed
self.rect.left = i.rect.right
settings.py
import pygame
FPS = 60
WIDTH = 800
HEIGHT = 600
TITLE = "Perfect collision"
GREY = (150,150,150)
BLACK = (0,0,0)
BLUE = (0,0,255)
SPEED = 5
JUMP_SPEED = 9
GRAVITY = 0.3
all_sprites = pygame.sprite.Group()
wall_sprites = pygame.sprite.Group()
