如何修复 Pygame 游戏中不需要的角色加速？

Question

我制作了一个游戏，角色必须在 2D 地图上获得金币（当你获得金币时，它会在随机位置重生），而运行远离移动的海绵宝宝类型角色随机的。如果你碰到海绵宝宝，你就会死。

我遇到的问题是我的角色有时会变慢，但有时当我用箭头键控制它时会随机变快。我在代码中更改值是不变的，所以有人可以向我解释这是行不通的吗？ Github Link

如果您不想打开 link，请使用以下代码：

import pygame
import random
import math
import time

pygame.init()
screen = pygame.display.set_mode((800,600))
pygame.display.set_caption("Survive the Spongey Boi")

#Sounds
game_over_sound = pygame.mixer.Sound("Game_Over.wav")
pygame.mixer.music.load("background.wav")
pygame.mixer.music.play(-1)

#Score
coins_collected = 0
font = pygame.font.Font('freesansbold.ttf', 32)
#coinfont = pygame.font.Font('freesansbold.ttf', 16)
#Positions of the text.
coin_textX = 10
coin_textY = 10

def show_coin_score(x,y):
    coins_text = font.render("Coins: " + str(coins_collected), True, (0,0,0))
    screen.blit(coins_text, (x,y))

#Player
playerImg = pygame.image.load('monster.png')
playerX = 370
playerY = 480
playerX_change = 0
playerY_change = 0

#Spongebob
enemyImg = pygame.image.load('sponge.png')
enemyX = random.randint(0,735)
enemyY = random.randint(10,400)
enemyX_change = 0
enemyY_change = 0

#Coin
coinImg = pygame.image.load('coin.png')
coinX = random.randint(0,735)
coinY = random.randint(0,535)

#Font for Game Over
over_font = pygame.font.Font('freesansbold.ttf', 64)

def player(x,y):
    screen.blit(playerImg, (x,y))

def enemy(x,y):
    screen.blit(enemyImg, (x,y))

def coin(x,y):
    screen.blit(coinImg, (x,y))

def isCollision(enemyX, enemyY, playerX, playerY):
    #Distance formula in Python
    distance = math.sqrt((math.pow(enemyX - playerX,2)) + (math.pow(enemyY - playerY,2))) 
    if distance < 27:
        return True
    else: 
        return False

def coin_collision(coinX, coinY, playerX, playerY):
    distance = math.sqrt((math.pow(coinX - playerX,2)) + (math.pow(coinY - playerY,2))) 
    if distance < 29:
        return True
    else: 
        return False

def game_over_text():
    over_text = over_font.render("GAME OVER", True, (0, 0, 0))
    screen.blit(over_text, (200,250))

#Game loop
running = True

while running:
    screen.fill((255,255,206))
    #Do the for loop here.
    for event in pygame.event.get():
        if event.type == pygame.QUIT:
            running = False
        #Do the keydown
        if event.type == pygame.KEYDOWN:
            if event.key == pygame.K_LEFT:
                playerX_change = -2
            if event.key == pygame.K_RIGHT:
                playerX_change = 2
            if event.key == pygame.K_UP:
                playerY_change = -2
            if event.key == pygame.K_DOWN:
                playerY_change = 2
        if event.type == pygame.KEYUP:
            if event.key == pygame.K_LEFT or event.key == pygame.K_RIGHT:
                playerX_change = 0
            if event.key == pygame.K_UP or event.key == pygame.K_DOWN:
                playerY_change = 0

    playerX += playerX_change
    playerY += playerY_change

    enemyX += enemyX_change
    enemyY += enemyY_change
    #Boundaries
    if playerX <= 0:
        playerX = 0
    elif playerX > 736:
        playerX = 736
    if playerY <= 0:
        playerY = 0
    elif playerY > 536:
        playerY = 536

    if enemyX <= 0:
        enemyX = 0
    elif enemyX > 736:
        enemyX = 736
    if enemyY <= 0:
        enemyY = 0
    elif enemyY > 536:
        enemyY = 536

    if isCollision(enemyX, enemyY, playerX, playerY):
        game_over_text()
        playerX = 10000
        enemyX = 10000
        pygame.mixer.Sound.play(game_over_sound)
        time.sleep(3.5)
        break
    if coin_collision(coinX, coinY, playerX, playerY):
        coins_collected += 1
        #time.sleep(0.00001)
        coinX = random.randint(0,735)
        coinY = random.randint(0,535)
    #CHANGE THIS LATER
    enemyX_change = random.randint(-15,15)
    enemyY_change = random.randint(-15,15)

    #score_value = score_value//1

    show_coin_score(coin_textX, coin_textY)
    coin(coinX, coinY)
    enemy(enemyX, enemyY)
    player(playerX, playerY)
    pygame.display.update()

Answer 1

不错的游戏！问题似乎是原因，因为您使用了 KEYDOW 和 KEYUP 事件。当您分别向上和向下更改左右之间的方向时，这可能会导致出现问题，因为移动在 KEYUP 上被取消了。

我建议使用 pygame.key.get_pressed 来获取密钥的当前状态。根据按键的状态分别设置playerX_changeplayerY_change：

while running:
    # [...]    

    for event in pygame.event.get():
        if event.type == pygame.QUIT:
            running = False

    keys = pygame.key.get_pressed()
    playerX_change, playerY_change = 0, 0
    if keys[pygame.K_LEFT]:
        playerX_change -= 2
    if keys[pygame.K_RIGHT]:
        playerX_change += 2
    if keys[pygame.K_UP]:
        playerY_change -= 2
    if keys[pygame.K_DOWN]:
        playerY_change += 2

旁注，使用 min and max 简化边界限制：

while running:
    # [...]

    #Boundaries
    playerX = max(0, min(736, playerX))
    playerY = max(0, min(536, playerY))
    enemyX  = max(0, min(736, enemyX))
    enemyY  = max(0, min(536, enemyY))

如何修复 Pygame 游戏中不需要的角色加速？

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pygame

game-physics