试图在pygame上制作一个自上而下的射击游戏，但在试图找出玩家移动时如何滚动地图时遇到困难

Question

我目前正在尝试制作一个自上而下的射击游戏，但是我在试图弄清楚角色移动（上、下、左、右）时如何移动地图时遇到了一些麻烦。我希望贴图始终填充屏幕，但当角色移动时，贴图将随之移动。我在网上寻找了一些解决方案，但很难将其应用到我自己的程序中

import pygame
pygame.display.set_caption("TEST")

clock = pygame.time.Clock()

class Player():

  def __init__(self,x,y):
    self.Image = pygame.image.load("myAvatar.png").convert()

    self.rect  = self.Image.get_rect(topleft = (x,y))

  def getX(self):
    return self.rect.x

  def getY(self):
    return self.rect.y

  def handle_keys(self,screenHeight,screenWidth):
      key = pygame.key.get_pressed()
      dist = 1 

      if key[pygame.K_DOWN]: 
          self.rect.y += dist
          if self.rect.y > screenHeight:
            self.rect.y = screenHeight
    
      elif key[pygame.K_UP]: 
          self.rect.y -= dist
          if self.rect.y < 0:
            self.rect.y = 0  
      if key[pygame.K_RIGHT]: 
          self.rect.x += dist
          if self.rect.x > screenWidth:
            self.rect.x = screenWidth
      elif key[pygame.K_LEFT]: 
          self.rect.x -= dist
          if self.rect.x < 0:
            self.rect.x = 0 

  def draw(self, game_window,screenX,screenY):
    self.Image = pygame.transform.scale(self.Image,(20,20))
    game_window.blit(self.Image, (screenX, screenY))


class Map():
  def __init__(self):
    self.Image = pygame.image.load("testbackground.jpg").convert()
    self.rect = self.Image.get_rect()
    self.rect.x = 0
    self.rect.y = 0

  def getX(self):
    return self.rect.x

  def getY(self):
    return self.rect.y

  def setX(self,newX):
    self.rect.x = newX
  
  def setY(self,newY):
    self.rect.y = newY

  def draw(self, game_window,screenX,screenY):
    self.Image = pygame.transform.scale(self.Image,(800,800))
    game_window.blit(self.Image,(screenX, screenY))


class Enemy():

  def __init__ (self,x,y):
    self.Image = pygame.image.load("WC.jpg").convert()
    self.rect  = self.Image.get_rect(topleft = (x,y))

  def draw(self, game_window):
    self.Image = pygame.transform.scale(self.Image,(20,20))
    game_window.blit(self.Image, (self.rect.x, self.rect.y))


pygame.init()

clock = pygame.time.Clock()
screenWidth = 400
screenHeight = 400
game_window = pygame.display.set_mode((screenWidth,screenHeight))
player = Player(200,200)
map = Map()
enemy = Enemy(250,250)
leave = False
while not leave:
  for event in pygame.event.get():
    if event.type == pygame.QUIT:
      pygame.quit() 
      running = False

  playerX = player.getX()
  playerY = player.getY()

  mapX = map.getX()
  mapY = map.getY()

  screenX = playerX - (screenWidth/2)
  if screenX < 0:
    screenX = 0
  if screenX > (mapX - screenWidth):
    screenX = (mapX - screenWidth)

  screenY = playerY - (screenHeight/2)
  if screenY < 0:
    screenY = 0
  if screenY > (mapY - screenHeight):
    screenY = (mapY - screenHeight)
  
  player.handle_keys(screenHeight,screenWidth)

  map.draw(game_window,screenX,screenY)
  enemy.draw(game_window)
  player.draw(game_window,screenX,screenY)
  pygame.display.update()
  pygame.display.flip()
  clock.tick(60)


pygame.quit()
quit()

Answer 1

可以像this question中那样移动摄影机：

基本上，每个精灵都有一个位置，并在屏幕上绘制如下：

pos_on_the_screen = (posX - cameraX, posY - cameraY)

---

然后，摄像机会像这样跟随玩家：

width, height = sceen_size
camera_pos = (player.posX - width / 2, player.posY - height / 2)

在这种情况下，播放器停留在屏幕中央

---

如果您想让相机跟随播放器，但又不想让播放器一直处于中间（它可能会移动一点，但不会退出屏幕），可以使用以下方法：

width, height = screen_size
if cameraX - playerX > 2 * width / 3: # player exits to the right
    cameraX = playerX - 2 * width / 3
elif cameraX - playerX < width / 3: # player exits to the left
    cameraX = playerX - width / 3
if cameraY - playerY > 2 * height / 3: # player exits to the bottom
    cameraY = playerY - 2 * height / 3
elif cameraY - playerY < height / 3: # player exits to the top
    cameraY = playerY - height / 3

在本例中，玩家永远不会离开此空间：

您还可以使用更紧凑的形式：

width, height = screen_size
cameraX = min(max(cameraX, playerX - 2 * width / 3), playerX - width / 3)
cameraY = min(max(cameraY, playerY - 2 * height / 3), playerY - height / 3)

例如：