Как реализовать коллизии силами только PyGame и Python?

import pygame as pg
 
 
def collide(dx, dy, rect: pg.Rect):
    global player
    if player.colliderect(rect):
        if dx > 0:
            player.right = rect.left
        if dx < 0:
            player.left = rect.right
        if dy > 0:
            player.bottom = rect.top
        if dy < 0:
            player.top = rect.bottom
 
def get_axis(negative, positive):
    if negative:
        return -1
    if positive:
        return 1
    else:
        return 0
 
 
WIDTH, HEIGHT = 1280, 720
CENTER = (WIDTH // 2, HEIGHT // 2)
FPS = 30
 
screen = pg.display.set_mode((WIDTH, HEIGHT))
run = True
clock = pg.time.Clock()
elapsed = 1 / FPS
 
player = pg.Rect(0, 0, 40, 40)
player.center = CENTER
 
direction = [0, 0]
 
my_rect1 = pg.Rect(100, CENTER[1] + 100, WIDTH - 100, 20)
 
while run:
    screen.fill((0, 0, 0))
    for event in pg.event.get():
        if event.type == pg.QUIT:
            run = False
 
    pg.draw.rect(screen, pg.Color("red"), player)
    pg.draw.rect(screen, pg.Color("green"), my_rect1)
 
    keys = pg.key.get_pressed()
    direction = get_axis(keys[pg.K_a], keys[pg.K_d]), get_axis(keys[pg.K_w], keys[pg.K_s])
 
    player.right += direction[0] * elapsed
    collide(direction[0], 0, my_rect1)
    player.bottom += direction[1] * elapsed
    collide(0, direction[1], my_rect1)
 
 
    pg.display.flip()
    elapsed = clock.tick(FPS)