用 Python 实现植物大战僵尸代码！

前言

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作者： marble_xu

GitHub地址：https://github.com/marblexu/PythonPlantsVsZombies

PS：如有需要Python学习资料的小伙伴可以加点击下方链接自行获取

http://note.youdao.com/noteshare?id=3054cce4add8a909e784ad934f956cef

功能介绍

最近一直在给这个植物大战僵尸游戏添加新的植物和僵尸, 因为网上的图片资源有限，能加的植物和僵尸比较少， 目前进展如下。

功能实现如下：

• 支持的植物类型：太阳花，豌豆射手，寒冰射手，坚果，樱桃炸弹。新增加植物：双重豌豆射手，三重豌豆射手，食人花 ，小喷菇，土豆地雷，倭瓜。

• 支持的僵尸类型：普通僵尸，棋子僵尸，路障僵尸，铁桶僵尸。新增加读报僵尸。

• 使用json文件保存关卡信息，设置僵尸出现的时间和位置。

• 增加每关开始时选择上场植物。

• 增加除草机。

下面是游戏的截图：

植物卡片选择和种植

如图所示，游戏中可以种植物的方格一共有45个（有5行，每行9列）。

这篇文章要介绍的是：

• 上方植物卡片栏的实现。

• 点击植物卡片，鼠标切换为植物图片。

• 鼠标移动时，判断当前在哪个方格中，并显示半透明的植物作为提示。

代码实现

所有的植物卡片的名称和属性都保存在单独的list中，每个list index都对应一种植物。

比如list index 0 就是太阳花：

• card_name_list[0] 是太阳花卡片的名字，用来获取太阳花卡片的图片。

• plant_name_list[0] 是太阳花的名字，用来获取太阳花卡片的图片。

• plant_sun_list[0] 是种植太阳花需要花费的太阳点数。

• plant_frozen_time_list[0] 是太阳花的冷却时间。

植物卡片类

每个植物卡片是一个单独的Card类，用来显示这个植物。

• checkMouseClick函数：判断鼠标是否点击到这个卡片；

• canClick：判断这个卡片是否能种植（有没有足够的点数，是否还在冷却时间内）；

• update 函数：通过设置图片的透明度来表示这个卡片是否能选择。

卡片栏类

MenuBar类显示图3中的植物卡片栏：

• self.sun_value：当前采集的太阳点数；

• self.card_list: 植物卡片的list；

• setupCards函数：遍历初始化init函数中传入这个关卡选好的植物卡片list，依次创建Card类，设置每个卡片的显示位置；

• checkCardClick函数：检查鼠标是否点击了卡片栏上的某个植物卡片，如果选择了一个可种植的卡片，返回结果。

代码：

 import pygame as pg
 from .. import tool
 from .. import constants as c
 ​
 PANEL_Y_START = 87
 PANEL_X_START = 22
 PANEL_Y_INTERNAL = 74
 PANEL_X_INTERNAL = 53
 CARD_LIST_NUM = 8
 ​
 card_name_list = [c.CARD_SUNFLOWER, c.CARD_PEASHOOTER, c.CARD_SNOWPEASHOOTER, c.CARD_WALLNUT,
                   c.CARD_CHERRYBOMB, c.CARD_THREEPEASHOOTER, c.CARD_REPEATERPEA, c.CARD_CHOMPER,
                   c.CARD_PUFFSHROOM, c.CARD_POTATOMINE, c.CARD_SQUASH, c.CARD_SPIKEWEED,
                   c.CARD_JALAPENO, c.CARD_SCAREDYSHROOM, c.CARD_SUNSHROOM, c.CARD_ICESHROOM]
 plant_name_list = [c.SUNFLOWER, c.PEASHOOTER, c.SNOWPEASHOOTER, c.WALLNUT,
                    c.CHERRYBOMB, c.THREEPEASHOOTER, c.REPEATERPEA, c.CHOMPER,
                    c.PUFFSHROOM, c.POTATOMINE, c.SQUASH, c.SPIKEWEED,
                    c.JALAPENO, c.SCAREDYSHROOM, c.SUNSHROOM, c.ICESHROOM]
 plant_sun_list = [50, 100, 175, 50, 150, 325, 200, 150, 0, 25, 50, 100, 125, 25, 25, 75]
 plant_frozen_time_list = [7500, 7500, 7500, 30000, 50000, 7500, 7500, 7500, 7500, 30000,
                           30000, 7500, 50000, 7500, 7500, 50000]
 all_card_list = [0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15]
 ​
 def getSunValueImage(sun_value):
     font = pg.font.SysFont(None, 22)
     width = 32
     msg_image = font.render(str(sun_value), True, c.NAVYBLUE, c.LIGHTYELLOW)
     msg_rect = msg_image.get_rect()
     msg_w = msg_rect.width
 ​
     image = pg.Surface([width, 17])
     x = width - msg_w
 ​
     image.fill(c.LIGHTYELLOW)
     image.blit(msg_image, (x, 0), (0, 0, msg_rect.w, msg_rect.h))
     image.set_colorkey(c.BLACK)
     return image
 ​
 class Card():
     def __init__(self, x, y, name_index, scale=0.78):
         self.loadFrame(card_name_list[name_index], scale)
         self.rect = self.orig_image.get_rect()
         self.rect.x = x
         self.rect.y = y

         self.name_index = name_index
         self.sun_cost = plant_sun_list[name_index]
         self.frozen_time = plant_frozen_time_list[name_index]
         self.frozen_timer = -self.frozen_time
         self.refresh_timer = 0
         self.select = True
 ​
     def loadFrame(self, name, scale):
         frame = tool.GFX[name]
         rect = frame.get_rect()
         width, height = rect.w, rect.h
 ​
         self.orig_image = tool.get_image(frame, 0, 0, width, height, c.BLACK, scale)
         self.image = self.orig_image
 ​
     def checkMouseClick(self, mouse_pos):
         x, y = mouse_pos
         if(x >= self.rect.x and x <= self.rect.right and
            y >= self.rect.y and y <= self.rect.bottom):
             return True
         return False
 ​
     def canClick(self, sun_value, current_time):
         if self.sun_cost <= sun_value and (current_time - self.frozen_timer) > self.frozen_time:
             return True
         return False
 ​
     def canSelect(self):
         return self.select
 ​
     def setSelect(self, can_select):
         self.select = can_select
         if can_select:
             self.image.set_alpha(255)
         else:
             self.image.set_alpha(128)
 ​
     def setFrozenTime(self, current_time):
         self.frozen_timer = current_time
 ​
     def createShowImage(self, sun_value, current_time):
         '''create a card image to show cool down status
            or disable status when have not enough sun value'''
         time = current_time - self.frozen_timer
         if time < self.frozen_time: #cool down status
             image = pg.Surface([self.rect.w, self.rect.h])
             frozen_image = self.orig_image.copy()
             frozen_image.set_alpha(128)
             frozen_height = (self.frozen_time - time)/self.frozen_time * self.rect.h

             image.blit(frozen_image, (0,0), (0, 0, self.rect.w, frozen_height))
             image.blit(self.orig_image, (0,frozen_height),
                        (0, frozen_height, self.rect.w, self.rect.h - frozen_height))
         elif self.sun_cost > sun_value: #disable status
             image = self.orig_image.copy()
             image.set_alpha(192)
         else:
             image = self.orig_image
         return image
 ​
     def update(self, sun_value, current_time):
         if (current_time - self.refresh_timer) >= 250:
             self.image = self.createShowImage(sun_value, current_time)
             self.refresh_timer = current_time
 ​
     def draw(self, surface):
         surface.blit(self.image, self.rect)
 ​
 class MenuBar():
     def __init__(self, card_list, sun_value):
         self.loadFrame(c.MENUBAR_BACKGROUND)
         self.rect = self.image.get_rect()
         self.rect.x = 10
         self.rect.y = 0

         self.sun_value = sun_value
         self.card_offset_x = 32
         self.setupCards(card_list)
 ​
     def loadFrame(self, name):
         frame = tool.GFX[name]
         rect = frame.get_rect()
         frame_rect = (rect.x, rect.y, rect.w, rect.h)
 ​
         self.image = tool.get_image(tool.GFX[name], *frame_rect, c.WHITE, 1)
 ​
     def update(self, current_time):
         self.current_time = current_time
         for card in self.card_list:
             card.update(self.sun_value, self.current_time)
 ​
     def createImage(self, x, y, num):
         if num == 1:
             return
         img = self.image
         rect = self.image.get_rect()
         width = rect.w
         height = rect.h
         self.image = pg.Surface((width * num, height)).convert()
         self.rect = self.image.get_rect()
         self.rect.x = x
         self.rect.y = y
         for i in range(num):
             x = i * width
             self.image.blit(img, (x,0))
         self.image.set_colorkey(c.BLACK)

     def setupCards(self, card_list):
         self.card_list = []
         x = self.card_offset_x
         y = 8
         for index in card_list:
             x += 55
             self.card_list.append(Card(x, y, index))
 ​
     def checkCardClick(self, mouse_pos):
         result = None
         for card in self.card_list:
             if card.checkMouseClick(mouse_pos):
                 if card.canClick(self.sun_value, self.current_time):
                     result = (plant_name_list[card.name_index], card.sun_cost)
                 break
         return result

     def checkMenuBarClick(self, mouse_pos):
         x, y = mouse_pos
         if(x >= self.rect.x and x <= self.rect.right and
            y >= self.rect.y and y <= self.rect.bottom):
             return True
         return False
 ​
     def decreaseSunValue(self, value):
         self.sun_value -= value
 ​
     def increaseSunValue(self, value):
         self.sun_value += value
 ​
     def setCardFrozenTime(self, plant_name):
         for card in self.card_list:
             if plant_name_list[card.name_index] == plant_name:
                 card.setFrozenTime(self.current_time)
                 break
 ​
     def drawSunValue(self):
         self.value_image = getSunValueImage(self.sun_value)
         self.value_rect = self.value_image.get_rect()
         self.value_rect.x = 21
         self.value_rect.y = self.rect.bottom - 21

         self.image.blit(self.value_image, self.value_rect)
 ​
     def draw(self, surface):
         self.drawSunValue()
         surface.blit(self.image, self.rect)
         for card in self.card_list:
             card.draw(surface)
 ​
 class Panel():
     def __init__(self, card_list, sun_value):
         self.loadImages(sun_value)
         self.selected_cards = []
         self.selected_num = 0
         self.setupCards(card_list)
 ​
     def loadFrame(self, name):
         frame = tool.GFX[name]
         rect = frame.get_rect()
         frame_rect = (rect.x, rect.y, rect.w, rect.h)
 ​
         return tool.get_image(tool.GFX[name], *frame_rect, c.WHITE, 1)
 ​
     def loadImages(self, sun_value):
         self.menu_image = self.loadFrame(c.MENUBAR_BACKGROUND)
         self.menu_rect = self.menu_image.get_rect()
         self.menu_rect.x = 0
         self.menu_rect.y = 0
 ​
         self.panel_image = self.loadFrame(c.PANEL_BACKGROUND)
         self.panel_rect = self.panel_image.get_rect()
         self.panel_rect.x = 0
         self.panel_rect.y = PANEL_Y_START
 ​

         self.value_image = getSunValueImage(sun_value)
         self.value_rect = self.value_image.get_rect()
         self.value_rect.x = 21
         self.value_rect.y = self.menu_rect.bottom - 21
 ​
         self.button_image =  self.loadFrame(c.START_BUTTON)
         self.button_rect = self.button_image.get_rect()
         self.button_rect.x = 155
         self.button_rect.y = 547
 ​
     def setupCards(self, card_list):
         self.card_list = []
         x = PANEL_X_START - PANEL_X_INTERNAL
         y = PANEL_Y_START + 43 - PANEL_Y_INTERNAL
         for i, index in enumerate(card_list):
             if i % 8 == 0:
                 x = PANEL_X_START - PANEL_X_INTERNAL
                 y += PANEL_Y_INTERNAL
             x += PANEL_X_INTERNAL
             self.card_list.append(Card(x, y, index, 0.75))
 ​
     def checkCardClick(self, mouse_pos):
         delete_card = None
         for card in self.selected_cards:
             if delete_card: # when delete a card, move right cards to left
                 card.rect.x -= 55
             elif card.checkMouseClick(mouse_pos):
                 self.deleteCard(card.name_index)
                 delete_card = card
 ​
         if delete_card:
             self.selected_cards.remove(delete_card)
             self.selected_num -= 1
 ​
         if self.selected_num == CARD_LIST_NUM:
             return
 ​
         for card in self.card_list:
             if card.checkMouseClick(mouse_pos):
                 if card.canSelect():
                     self.addCard(card)
                 break
 ​
     def addCard(self, card):
         card.setSelect(False)
         y = 8
         x = 78 + self.selected_num * 55
         self.selected_cards.append(Card(x, y, card.name_index))
         self.selected_num += 1
 ​
     def deleteCard(self, index):
         self.card_list[index].setSelect(True)
 ​
     def checkStartButtonClick(self, mouse_pos):
         if self.selected_num < CARD_LIST_NUM:
             return False
 ​
         x, y = mouse_pos
         if (x >= self.button_rect.x and x <= self.button_rect.right and
             y >= self.button_rect.y and y <= self.button_rect.bottom):
            return True
         return False
 ​
     def getSelectedCards(self):
         card_index_list = []
         for card in self.selected_cards:
             card_index_list.append(card.name_index)
         return card_index_list
 ​
     def draw(self, surface):
         self.menu_image.blit(self.value_image, self.value_rect)
         surface.blit(self.menu_image, self.menu_rect)
         surface.blit(self.panel_image, self.panel_rect)
         for card in self.card_list:
             card.draw(surface)
         for card in self.selected_cards:
             card.draw(surface)
 ​
         if self.selected_num == CARD_LIST_NUM:
             surface.blit(self.button_image, self.button_rect)

鼠标图片切换

setupMouseImage 函数实现鼠标图片切换为选中的植物：

• self.mouse_image ：根据 plant_name 获取选中的植物图片；

• self.mouse_rect：选中植物图片的位置，在drawMouseShow函数中，需要将植物图片的位置设置成当前鼠标的位置；

• pg.mouse.set_visible(False)：隐藏默认的鼠标显示，这样效果就是鼠标图片切换为选中的植物了。

    def setupMouseImage(self, plant_name, plant_cost):
         frame_list = tool.GFX[plant_name]
         if plant_name in tool.PLANT_RECT:
             data = tool.PLANT_RECT[plant_name]
             x, y, width, height = data['x'], data['y'], data['width'], data['height']
         else:
             x, y = 0, 0
             rect = frame_list[0].get_rect()
             width, height = rect.w, rect.h
 ​
 ​
         if plant_name == c.POTATOMINE or plant_name == c.SQUASH:
             color = c.WHITE
         else:
             color = c.BLACK
         self.mouse_image = tool.get_image(frame_list[0], x, y, width, height, color, 1)
         self.mouse_rect = self.mouse_image.get_rect()
         pg.mouse.set_visible(False)
         self.drag_plant = True
         self.plant_name = plant_name
         self.plant_cost = plant_cost
 ​
 ​
     def drawMouseShow(self, surface):
         if self.hint_plant:
             surface.blit(self.hint_image, self.hint_rect)
         x, y = pg.mouse.get_pos()
         self.mouse_rect.centerx = x
         self.mouse_rect.centery = y
         surface.blit(self.mouse_image, self.mouse_rect)

提示种在哪个方格中

先看下map类，代码在source\component\map.py 中：

• self.map：二维list，用来保存每个方格的状态。每个entry初始化为 0, 表示可以种植物，值为1时表示这个方格已经种了植物。

• getMapIndex 函数：传入参数是游戏中的坐标位置（比如当前鼠标的位置），返回该位置在地图的哪个方格中。

• getMapGridPos 函数：传入一个方格的index，返回在该方格中种植物的坐标位置。

• showPlant 函数：根据传入的坐标位置，判断该位置所在的方格是否能种植物，如果能种，就返回返回在该方格中种植物的坐标位置。

 MAP_EMPTY = 0
 MAP_EXIST = 1
 ​
 ​
 class Map():
     def __init__(self, width, height):
         self.width = width
         self.height = height
         self.map = [[0 for x in range(self.width)] for y in range(self.height)]
 ​
 ​
     def isValid(self, map_x, map_y):
         if (map_x < 0 or map_x >= self.width or
             map_y < 0 or map_y >= self.height):
             return False
         return True
 ​
     def isMovable(self, map_x, map_y):
         return (self.map[map_y][map_x] == c.MAP_EMPTY)
 ​
     def getMapIndex(self, x, y):
         x -= c.MAP_OFFSET_X
         y -= c.MAP_OFFSET_Y
         return (x // c.GRID_X_SIZE, y // c.GRID_Y_SIZE)
 ​
     def getMapGridPos(self, map_x, map_y):
         return (map_x * c.GRID_X_SIZE + c.GRID_X_SIZE//2 + c.MAP_OFFSET_X,
                 map_y * c.GRID_Y_SIZE + c.GRID_Y_SIZE//5 * 3 + c.MAP_OFFSET_Y)
 ​
     def setMapGridType(self, map_x, map_y, type):
         self.map[map_y][map_x] = type
 ​
 ​
     def getRandomMapIndex(self):
         map_x = random.randint(0, self.width-1)
         map_y = random.randint(0, self.height-1)
         return (map_x, map_y)
 ​
 ​
     def showPlant(self, x, y):
         pos = None
         map_x, map_y = self.getMapIndex(x, y)
         if self.isValid(map_x, map_y) and self.isMovable(map_x, map_y):
             pos = self.getMapGridPos(map_x, map_y)
         return pos

代码在source\state\level.py中：

• canSeedPlant 函数：判断当前鼠标位置能否种植物；

• setupHintImage 函数：如果当前鼠标位置能种植物，且有选择了一个植物卡片，则设置self.hint_image 显示当前会在哪一个方格中种植物，self.hint_rect 是植物种的坐标位置。

     def canSeedPlant(self):
         x, y = pg.mouse.get_pos()
         return self.map.showPlant(x, y)
 ​
     def setupHintImage(self):
         pos = self.canSeedPlant()
         if pos and self.mouse_image:
             if (self.hint_image and pos[0] == self.hint_rect.x and
                 pos[1] == self.hint_rect.y):
                 return
             width, height = self.mouse_rect.w, self.mouse_rect.h
             image = pg.Surface([width, height])
             image.blit(self.mouse_image, (0, 0), (0, 0, width, height))
             image.set_colorkey(c.BLACK)
             image.set_alpha(128)
             self.hint_image = image
             self.hint_rect = image.get_rect()
             self.hint_rect.centerx = pos[0]
             self.hint_rect.bottom = pos[1]
             self.hint_plant = True
         else:
             self.hint_plant = False