pygame製作遊戲人物精靈的行走及二段跳實現方法

不得不承認《Python 遊戲編程入門》這本書翻譯、排版非常之爛，但是裡面的demo還是很好的，之前做了些改編放到這裡。

先是素材：

背景

精靈

所有素材均取自此書

接下來就是精靈類的建立了：

 (self)        self.master_image === -1= 1= 1=== 1============rect == (rect.width // width) * (rect.height // height) - 1 update(self, current_time, rate=30 current_time > self.last_time ++= 1 self.frame >== self.frame !== (self.frame % self.columns) *= (self.frame // self.columns) *=== self.frame

將精靈類“放置”到遊戲螢幕上，並加上背景

pygame.init()screen = pygame.display.set_mode((800, 600))font = pygame.font.Font(None, 24)framerate = pygame.time.Clock()bg = pygame.image.load("background.png").convert_alpha()pl = pygame.image.load('caveman.png').convert_alpha()# 建立精靈組group = pygame.sprite.Group()player = MySprite(screen)player.load("caveman.png", 50, 64, 8)player.first_frame = 1player.last_frame = 7player.position = 400, 303group.add(player)while True:for event in pygame.event.get():if event.type == QUIT:            sys.exit()#   設定幀數framerate.tick(30)    ticks = pygame.time.get_ticks()

這樣的話精靈就在畫布上了，我們得讓它能左右移動：

keys = pygame.key.get_pressed()if keys[K_ESCAPE]:        sys.exit()if keys[K_RIGHT]:        player.X += 8if keys[K_LEFT]:if player.X > 0:            player.X -= 8

然後實現跳躍及二段跳躍

這裡需要說下二段跳躍的注意點：

1.直到落地前，只能跳兩次，也就是說精靈進行二次跳躍後不能再跳了

2.按下空格後，精靈的加速度重設

,這需要修改前面的代碼:

jump_vel = 0.0#   設定一個記錄跳躍次數的變數space_number = 0#   跳躍判斷player_jumping = Falseplayer_start_y = player.Ywhile True:for event in pygame.event.get():if event.type == QUIT:            sys.exit()if event.type == KEYDOWN:if event.key == K_SPACE:#   跳躍次數小於2次時，if space_number < 2:                    jump_vel = -15.0space_number += 1player_jumping = True    keys = pygame.key.get_pressed()if keys[K_ESCAPE]:        sys.exit()if keys[K_RIGHT]:        player.X += 8if keys[K_LEFT]:if player.X > 0:            player.X -= 8#   設定幀數framerate.tick(30)    ticks = pygame.time.get_ticks()#   當按下空格後，jump_vel變數不斷變大，直到接觸地面if player_jumping:        player.Y += jump_vel        jump_vel += 2#   落地後，重設跳躍速度和其他判斷變數if player.Y >= player_start_y:                player_jumping = False                player.Y = player_start_y                jump_vel = 0                space_number = 0#   建立背景    screen.blit(bg, (0, 0))# 精靈組更新group.update(ticks, 50)    group.draw(screen)    pygame.display.update()

所有代碼:

import sys, time, random, math, pygamefrom pygame.locals import *class MySprite(pygame.sprite.Sprite):def __init__(self, target):        pygame.sprite.Sprite.__init__(self)        self.master_image = None        self.frame = 0        self.old_frame = -1self.frame_width = 1self.frame_height = 1self.first_frame = 0        self.last_frame = 0        self.columns = 1self.last_time = 0# 　　使用property方法，讓精靈類對座標操作更方便def _getx(self):return self.rect.xdef _setx(self, value):        self.rect.x = value    X = property(_getx, _setx)def _gety(self):return self.rect.ydef _sety(self, value):        self.rect.y = value    Y = property(_gety, _sety)def _getpos(self):return self.rect.topleftdef _setpos(self, pos):        self.rect.topleft = pos    position = property(_getpos, _setpos)def load(self, filename, width, height, columns):        self.master_image = pygame.image.load(filename).convert_alpha()        self.frame_width = width        self.frame_height = height        self.rect = Rect(0, 0, width, height)        self.columns = columns        rect = self.master_image.get_rect()        self.last_frame = (rect.width // width) * (rect.height // height) - 1def update(self, current_time, rate=30):# 　　更新幀數if current_time > self.last_time + rate:            self.frame += 1if self.frame > self.last_frame:                self.frame = self.first_frame            self.last_time = current_time# 當幀數發生改變時，建立新的圖片if self.frame != self.old_frame:            frame_x = (self.frame % self.columns) * self.frame_width            frame_y = (self.frame // self.columns) * self.frame_height            rect = Rect(frame_x, frame_y, self.frame_width, self.frame_height)            self.image = self.master_image.subsurface(rect)            self.old_frame = self.framepygame.init()screen = pygame.display.set_mode((800, 600))font = pygame.font.Font(None, 24)framerate = pygame.time.Clock()bg = pygame.image.load("background.png").convert_alpha()pl = pygame.image.load('caveman.png').convert_alpha()# 建立精靈組group = pygame.sprite.Group()player = MySprite(screen)player.load("caveman.png", 50, 64, 8)player.first_frame = 1player.last_frame = 7player.position = 400, 303group.add(player)jump_vel = 0.0#   設定一個記錄跳躍次數的變數space_number = 0#   跳躍判斷player_jumping = Falseplayer_start_y = player.Ywhile True:for event in pygame.event.get():if event.type == QUIT:            sys.exit()if event.type == KEYDOWN:if event.key == K_SPACE:#   跳躍次數小於2次時，if space_number < 2:                    jump_vel = -15.0space_number += 1player_jumping = True    keys = pygame.key.get_pressed()if keys[K_ESCAPE]:        sys.exit()if keys[K_RIGHT]:        player.X += 8if keys[K_LEFT]:if player.X > 0:            player.X -= 8#   設定幀數framerate.tick(30)    ticks = pygame.time.get_ticks()#   當按下空格後，jump_vel變數不斷變大，直到接觸地面if player_jumping:        player.Y += jump_vel        jump_vel += 2#   落地後if player.Y >= player_start_y:                player_jumping = False                player.Y = player_start_y                jump_vel = 0                space_number = 0                rush_number = 0#   建立背景    screen.blit(bg, (0, 0))# 精靈組更新group.update(ticks, 50)    group.draw(screen)    pygame.display.update()

這樣，一個粗糙的、會二段跳的精靈就完成了。

很感謝這本書提供單次跳躍的思路，讓我有思考二段跳的想法。其實像二段跳這類看上去容易，但實現其實還是需要思考一番的。