pygame 精靈的行走及二段跳實現方法
阿新 • • 發佈：2017-07-10
blank wid port rdquo mas dem nbsp turn 改變
不得不承認《Python遊戲編程入門》這本書翻譯、排版非常之爛，但是裏面的demo還是很好的，之前做了些改編放到這裏。
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創建了：
class MySprite(pygame.sprite.Sprite): def __init__(self, target): pygame.sprite.Sprite.__init__(self) self.master_image = None self.frame = 0 self.old_frame= -1 self.frame_width = 1 self.frame_height = 1 self.first_frame = 0 self.last_frame = 0 self.columns = 1 self.last_time = 0 # 使用property方法，讓精靈類對坐標操作更方便 def _getx(self): return self.rect.x def _setx(self, value): self.rect.x= value X = property(_getx, _setx) def _gety(self): return self.rect.y def _sety(self, value): self.rect.y = value Y = property(_gety, _sety) def _getpos(self): return self.rect.topleft def _setpos(self, pos): self.rect.topleft= pos position = property(_getpos, _setpos)
# load方法中定義了圖片位置，長寬和幀的列數，由此來將素材切成一幀一幀 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) - 1 def update(self, current_time, rate=30): # 更新幀數 if current_time > self.last_time + rate: self.frame += 1 if self.frame > self.last_frame: self.frame = self.first_frame self.last_time = current_time # 當幀數發生改變時，創建新的圖片 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.frame
將精靈類“放置”到遊戲屏幕上，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() # 創建精靈組 group = pygame.sprite.Group() player = MySprite(screen) player.load("caveman.png", 50, 64, 8) player.first_frame = 1 player.last_frame = 7 player.position = 400, 303 group.add(player) while True: for event in pygame.event.get(): if event.type == QUIT: sys.exit() # 設置幀數 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 += 8 if keys[K_LEFT]: if player.X > 0: player.X -= 8
然後實現跳躍及二段跳躍
這裏需要說下二段跳躍的註意點：
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，精靈的加速度重置
,這需要修改前面的代碼:
jump_vel = 0.0 # 設置一個記錄跳躍次數的變量 space_number = 0 # 跳躍判斷 player_jumping = False player_start_y = player.Y while 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 = -15.0 space_number += 1 player_jumping = True keys = pygame.key.get_pressed() if keys[K_ESCAPE]: sys.exit() if keys[K_RIGHT]: player.X += 8 if keys[K_LEFT]: if player.X > 0: player.X -= 8 # 設置幀數 framerate.tick(30) ticks = pygame.time.get_ticks() # 當按下空格後，jump_vel變量不斷變大，直到接觸地面 if player_jumping: player.Y += jump_vel jump_vel += 2 # 落地後，重置跳躍速度和其他判斷變量 if player.Y >= player_start_y: player_jumping = False player.Y = player_start_y jump_vel = 0 space_number = 0 # 創建背景 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, pygame from 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 = -1 self.frame_width = 1 self.frame_height = 1 self.first_frame = 0 self.last_frame = 0 self.columns = 1 self.last_time = 0 # 使用property方法，讓精靈類對坐標操作更方便 def _getx(self): return self.rect.x def _setx(self, value): self.rect.x = value X = property(_getx, _setx) def _gety(self): return self.rect.y def _sety(self, value): self.rect.y = value Y = property(_gety, _sety) def _getpos(self): return self.rect.topleft def _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) - 1 def update(self, current_time, rate=30): # 更新幀數 if current_time > self.last_time + rate: self.frame += 1 if self.frame > self.last_frame: self.frame = self.first_frame self.last_time = current_time # 當幀數發生改變時，創建新的圖片 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.frame 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() # 創建精靈組 group = pygame.sprite.Group() player = MySprite(screen) player.load("caveman.png", 50, 64, 8) player.first_frame = 1 player.last_frame = 7 player.position = 400, 303 group.add(player) jump_vel = 0.0 # 設置一個記錄跳躍次數的變量 space_number = 0 # 跳躍判斷 player_jumping = False player_start_y = player.Y while 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 = -15.0 space_number += 1 player_jumping = True keys = pygame.key.get_pressed() if keys[K_ESCAPE]: sys.exit() if keys[K_RIGHT]: player.X += 8 if keys[K_LEFT]: if player.X > 0: player.X -= 8 # 設置幀數 framerate.tick(30) ticks = pygame.time.get_ticks() # 當按下空格後，jump_vel變量不斷變大，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 # 創建背景 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。
pygame 精靈的行走及二段跳實現方法