Python 如何在pygame中鼠标在2D平铺地图上滚动？

我正在尝试使用pygame，我使用了一些我发现的示例来学习和创建一个简单的应用程序。我的下一个目标是创建一个比屏幕大的2D平铺贴图，然后能够用鼠标滚动。我想做一个类似于战略游戏的东西，如果你将鼠标移动到屏幕边缘，“卡马拉”将朝那个方向移动，显示地图的那一部分（如果卡马拉到达地图的末端，我也想停止它）。此时，如果我将鼠标悬停在边缘上，它将只移动一次

import pygame, os
from pygame.locals import *

BLACK = (0, 0, 0)
WHITE = (255, 255, 255)
RED = (255, 0, 0)

SCREEN_WIDTH = 5*40
SCREEN_HEIGHT = 7*40

#functions to create our resources
def load_image(name, colorkey=None):
    try:
        image = pygame.image.load(name) 
    except pygame.error, message:
        print 'Cannot load image:', name
        raise SystemExit, message
    image = image.convert_alpha()
    if colorkey is not None:
        if colorkey is -1:
            colorkey = image.get_at((0,0))
        image.set_colorkey(colorkey, RLEACCEL)
    return image, image.get_rect()

#classes for our game objects
class Camera(object):
    def __init__(self, camera_func, width, height):
        self.camera_func = camera_func
        self.state = pygame.Rect(100,100, width, height)

    def apply(self, rect):
        l, t, w, h = rect

        if 0 <= self.state[0] <= (SCREEN_WIDTH/5):
            l += 10
        elif (SCREEN_WIDTH - (SCREEN_WIDTH/5)) < self.state[0] <= SCREEN_WIDTH:
            l -=10

        if 0 <= self.state[1] <= (SCREEN_HEIGHT/5):
            t += 10
        elif (SCREEN_HEIGHT - (SCREEN_HEIGHT/5)) < self.state[1] <= SCREEN_HEIGHT:
            t -=10

        return rect.move(l,t)

    def update(self):
        pos = pygame.mouse.get_pos()
        self.state.topleft = pos
        #self.state = self.camera_func(self.state)

def complex_camera(camera):
    l, t, w, h = camera
    l, t, _, _ = -l, -t, w, h

    l = min(0, l)                           # stop scrolling at the left edge
    l = max(-(camera.width-SCREEN_WIDTH), l)   # stop scrolling at the right edge
    t = max(-(camera.height-SCREEN_HEIGHT), t) # stop scrolling at the bottom
    t = min(0, t)                           # stop scrolling at the top
    return pygame.Rect(l, t, w, h)

def main ():

    pygame.init()

    screen = pygame.display.set_mode([SCREEN_WIDTH, SCREEN_HEIGHT])

    pygame.display.set_caption("W40K")

    grasstile = pygame.image.load('./textures/grass.png')
    watertile = pygame.image.load('./textures/water.png')
    waterbeach = pygame.image.load('./textures/dirt.png')

    grassrect = grasstile.get_rect()
    waterrect = watertile.get_rect()
    waterb = waterbeach.get_rect()

    TILESIZE = 40

    tilemap = [

        [grasstile,grasstile,waterbeach,waterbeach,watertile,watertile,waterbeach,waterbeach,grasstile,grasstile,waterbeach,watertile,watertile,watertile,waterbeach,waterbeach,waterbeach,grasstile,grasstile,waterbeach],   
        [grasstile,waterbeach,waterbeach,waterbeach,watertile,watertile,watertile,waterbeach,grasstile,grasstile,waterbeach,watertile,watertile,watertile,waterbeach,waterbeach,waterbeach,grasstile,grasstile,waterbeach],
        [waterbeach,waterbeach,waterbeach,waterbeach,watertile,watertile,watertile,waterbeach,grasstile,grasstile,waterbeach,watertile,watertile,watertile,waterbeach,waterbeach,waterbeach,grasstile,grasstile,waterbeach],
        [grasstile,waterbeach,waterbeach,waterbeach,waterbeach,waterbeach,grasstile,waterbeach,grasstile,grasstile,waterbeach,watertile,watertile,watertile,waterbeach,waterbeach,waterbeach,grasstile,grasstile,waterbeach],
        [grasstile,grasstile,waterbeach,waterbeach,watertile,watertile,waterbeach,waterbeach,grasstile,grasstile,waterbeach,waterbeach,watertile,watertile,waterbeach,waterbeach,waterbeach,grasstile,grasstile,waterbeach],
        [watertile,grasstile,waterbeach,watertile,watertile,watertile,waterbeach,waterbeach,grasstile,grasstile,waterbeach,watertile,watertile,watertile,waterbeach,waterbeach,waterbeach,grasstile,grasstile,waterbeach],
        [watertile,watertile,waterbeach,waterbeach,waterbeach,waterbeach,waterbeach,waterbeach,grasstile,grasstile,waterbeach,waterbeach,watertile,watertile,waterbeach,waterbeach,waterbeach,grasstile,grasstile,waterbeach],
        [grasstile,watertile,waterbeach,waterbeach,grasstile,grasstile,waterbeach,waterbeach,grasstile,grasstile,waterbeach,waterbeach,waterbeach,waterbeach,waterbeach,waterbeach,waterbeach,grasstile,grasstile,waterbeach],
        [grasstile,grasstile,waterbeach,waterbeach,watertile,watertile,waterbeach,waterbeach,grasstile,grasstile,waterbeach,watertile,watertile,watertile,waterbeach,waterbeach,waterbeach,grasstile,grasstile,waterbeach],
        [grasstile,grasstile,waterbeach,waterbeach,watertile,watertile,waterbeach,waterbeach,grasstile,grasstile,waterbeach,grasstile,watertile,watertile,waterbeach,waterbeach,waterbeach,grasstile,grasstile,waterbeach],
        [grasstile,grasstile,waterbeach,waterbeach,watertile,watertile,waterbeach,waterbeach,grasstile,grasstile,waterbeach,watertile,grasstile,watertile,waterbeach,waterbeach,waterbeach,grasstile,grasstile,waterbeach],
        [grasstile,grasstile,waterbeach,waterbeach,watertile,watertile,waterbeach,waterbeach,grasstile,grasstile,waterbeach,watertile,watertile,watertile,waterbeach,waterbeach,waterbeach,grasstile,grasstile,waterbeach],
        [grasstile,grasstile,waterbeach,waterbeach,watertile,watertile,waterbeach,waterbeach,grasstile,grasstile,waterbeach,watertile,watertile,watertile,waterbeach,waterbeach,waterbeach,grasstile,grasstile,waterbeach],
        [grasstile,grasstile,waterbeach,waterbeach,watertile,watertile,waterbeach,waterbeach,grasstile,grasstile,waterbeach,watertile,watertile,watertile,waterbeach,waterbeach,waterbeach,grasstile,grasstile,waterbeach],
        [grasstile,grasstile,waterbeach,waterbeach,watertile,watertile,waterbeach,waterbeach,grasstile,grasstile,waterbeach,watertile,watertile,watertile,waterbeach,waterbeach,waterbeach,grasstile,grasstile,waterbeach],
    ]

    #Creates surface of the background
    map_surface = pygame.Surface((len(tilemap[0])*TILESIZE, len(tilemap)*TILESIZE))
    #Display the surface
    for y,row in enumerate(tilemap):
        for x,tile_surface in enumerate(row):
            map_surface.blit(tile_surface,(x*TILESIZE,y*TILESIZE))

    total_level_width = len(tilemap[0]) * 40
    total_level_height = len(tilemap) * 40

    camera = Camera(complex_camera,total_level_width, total_level_height)

    #mouse = Mouse()
    #allsprites = pygame.sprite.RenderPlain((mouse))

    clock = pygame.time.Clock()

    while 1:
        clock.tick(60)

    #Handle Input Events
        for event in pygame.event.get():
            if event.type == QUIT:
                return
            elif event.type == KEYDOWN and event.key == K_ESCAPE:
                return

        screen.fill(BLACK)

        #Camera moves.
        camera.update()

        #Display background.
        screen.blit(map_surface, camera.apply(waterrect))

        pygame.display.flip()

if __name__ == "__main__":
    main()

pygame.quit()

导入pygame，操作系统
从pygame.locals导入*
黑色=（0,0,0）
白色=（255，255，255）
红色=（255,0,0）
屏幕宽度=5*40
屏幕高度=7*40
#创建我们的资源的功能
def load_图像（名称，colorkey=None）：
尝试：
image=pygame.image.load（名称）
除了pygame.error，消息：
打印“无法加载图像：”，名称
升起系统退出，消息
image=image.convert_alpha（）
如果colorkey不是None：
如果colorkey为-1：
colorkey=image.get_位于（（0,0））
图像。设置颜色键（颜色键，RLEACCEL）
返回image，image.get_rect（）
#我们的游戏对象的类
类摄影机（对象）：
定义初始值（自身、相机功能、宽度、高度）：
self.camera\u func=camera\u func
self.state=pygame.Rect（100100，宽度，高度）
def应用（自身、rect）：
l、 t，w，h=rect
如果0我很难说你的sode到底出了什么问题（我在编码方面的经验太少），但我刚刚意识到在我的脚本中用鼠标移动屏幕，我做到了：

screen=pygame.display.set_mode((WINDOWWIDTH,WINDOWHEIGHT),32)

Map=pygame.image.load(os.path.join('Image','MAP.png')).convert_alpha()

startX,startY=0,0                   # starting coordinates for Map

while 1:
    screen.fill(white)
    screen.blit(Map,(startX,startY))

    for event in pygame.event.get():
        if event.type == MOUSEMOTION :
            mousepos=pygame.mouse.get_pos()

    if WINDOWHEIGHT-mousepos[1]<50:     # if  y-position of mouse is 50 pixel far from lower edge ..
        startY -= 5                     # ..move Map by 5 px
    if mousepos [1]<50:
        startY += 5
    if mousepos [0]<50 :
        startX += 5
    if WINDOWWIDTH - mousepos[0]<50:
        startX -= 5

    pygame.display.flip()

screen=pygame.display.set_模式（（窗口宽度，窗口高度），32）
Map=pygame.image.load（os.path.join（'image'，'Map.png'））.convert_alpha（）
startX，startY=0,0#地图的起始坐标
而1：
屏幕填充（白色）
屏幕。blit（地图，（startX，startY））
对于pygame.event.get（）中的事件：
如果event.type==MOUSEMOTION：
mousepos=pygame.mouse.get_pos（）
如果WINDOWHEIGHT鼠标点[1]无人愿意回答：(