[Python] Spaceship游戏初步实现 Mini-project #7

本文主要是介绍[Python] Spaceship游戏初步实现 Mini-project #7，希望对大家解决编程问题提供一定的参考价值，需要的开发者们随着小编来一起学习吧！

Spaceship顾名思义是一款太空游戏，受经典的街机游戏Asteroid(1979)启发编写而成。在Mini-project #7中，我们先实现飞船的控制、导弹的发射、星球的随机出现和运动，简单设置UI，从而展示Lives和Score。在Mini-project #8中会增加更多功能。

具体思路如下（注：这次描述不是按照代码显示顺序，而是按照完成的思路写的）：

游戏细节描述在Coursera的interactive-python教程中，见此：https://www.coursera.org/learn/interactive-python-2/supplement/2ZVsF/mini-project-description

首先导入所需库，设置全局变量

import simplegui
import math
import random# globals for user interface
WIDTH = 800
HEIGHT = 600
score = 0
lives = 3
time = 0

1. 创建飞船类

# Ship class
class Ship:def __init__(self, pos, vel, angle, image, info):self.pos = [pos[0],pos[1]]self.vel = [vel[0],vel[1]]self.thrust = Falseself.angle = angleself.angle_vel = 0self.image = imageself.image_center = info.get_center()self.image_size = info.get_size()self.radius = info.get_radius()def draw(self,canvas):#canvas.draw_circle(self.pos, self.radius, 1, "White", "White")if self.thrust: #change image statuscanvas.draw_image(self.image, [130, 45], self.image_size, self.pos, self.image_size, self.angle)else:canvas.draw_image(self.image, self.image_center, self.image_size, self.pos, self.image_size, self.angle)def update(self): #这里是重头戏，飞船的加速度改变影响速度，速度也受阻力影响#update angleself.angle += self.angle_velc = 0.2#update positionself.pos[0] = (self.pos[0] + self.vel[0]) % WIDTHself.pos[1] = (self.pos[1] + self.vel[1]) % HEIGHT#update velocityself.vel[0] *= (1-c) #摩擦力self.vel[1] *= (1-c)if self.thrust:forward = angle_to_vector(self.angle)self.vel[0] += forward[0]self.vel[1] += forward[1]#change angle
def set_thrust(self, on):
self.thrust = on
if on: #add sound to thrust
ship_thrust_sound.rewind()
ship_thrust_sound.play()
else:
ship_thrust_sound.pause()

    def increase_angvel(self):self.angle_vel += .05def decrease_angvel(self):self.angle_vel -= .05#add missile and shootingdef shoot(self):global a_missileforward = angle_to_vector(self.angle)pos = [self.pos[0], self.pos[1]]pos[0] += vel[0] + self.radiuspos[1] += vel[1] + self.radiusvel[0] = self.vel[0] + (vel[0] * 6)vel[1] = self.vel[1] + (vel[1] * 6)a_missile = Sprite(pos, vel, self.angle, 0, missile_image, missile_info, missile_sound)

def increase_angvel(self): self.angle_vel += .05 #试合适的值 def decrease_angvel(self): self.angle_vel -= .05 #add missile and shooting 发射导弹 def shoot(self): global a_missile forward = angle_to_vector(self.angle) missile_pos = [self.pos[0]+self.radius*forward[0],self.pos[1]+self.radius*forward[1]] missile_vel = [self.vel[0]+5*forward[0], self.vel[1]+5*forward[1]] a_missile = Sprite(missile_pos, missile_vel, self.angle, 0, missile_image, missile_info, missile_sound) #使用Sprite类，见下面说明

键盘控制：

def keydown(key):if key == simplegui.KEY_MAP['left']: #逆时针旋转 所以decrease angle_velocitymy_ship.decrease_angvel()elif key == simplegui.KEY_MAP['right']:my_ship.increase_angvel()elif key == simplegui.KEY_MAP['up']:my_ship.set_thrust(True)elif key == simplegui.KEY_MAP['space']:my_ship.shoot()def keyup(key):if key == simplegui.KEY_MAP["left"]:my_ship.increase_angvel()elif key == simplegui.KEY_MAP['right']:my_ship.decrease_angvel()elif key == simplegui.KEY_MAP['up']:my_ship.set_thrust(False)

要想键盘能控制，在注册处理器(register handlers)时要添加set_keydown_handler和set_keyup_handler（最后代码中有写）

frame.set_keydown_handler(keydown)#添加键盘控制
frame.set_keyup_handler(keyup)

2. 创建Sprite类。星石(rock)、导弹(missile)都会使用该类

# Sprite class
class Sprite:def __init__(self, pos, vel, ang, ang_vel, image, info, sound = None):self.pos = [pos[0],pos[1]]self.vel = [vel[0],vel[1]]self.angle = angself.angle_vel = ang_velself.image = imageself.image_center = info.get_center()self.image_size = info.get_size()self.radius = info.get_radius()self.lifespan = info.get_lifespan()self.animated = info.get_animated()self.age = 0if sound:sound.rewind()sound.play()def draw(self, canvas):# 第二个self.image_size是指按图像大小显示canvas.draw_image(self.image, self.image_center, self.image_size, self.pos, self.image_size, self.angle)def update(self):self.angle += self.angle_vel # make the sprite move and rotateself.pos[0] = (self.pos[0]+self.vel[0])%WIDTHself.pos[1] = (self.pos[1]+self.vel[1])%HEIGHT

创建函数使星石定时随机产生

# timer handler that spawns a rock    
def rock_spawner(): #set a_rock to be a new rock on every tickglobal a_rocka_rock = Sprite([random.randrange(WIDTH),random.randrange(HEIGHT)], [random.randrange(-1,1),random.randrange(-1,1)], 0.05, 0.05, asteroid_image, asteroid_info)

3. 在画面中显示背景、星云等

def draw(canvas):global time#计时# animiate backgroundtime += 1wtime = (time / 4) % WIDTHcenter = debris_info.get_center()size = debris_info.get_size()canvas.draw_image(nebula_image, nebula_info.get_center(), nebula_info.get_size(), [WIDTH / 2, HEIGHT / 2], [WIDTH, HEIGHT])canvas.draw_image(debris_image, center, size, (wtime - WIDTH / 2, HEIGHT / 2), (WIDTH, HEIGHT))canvas.draw_image(debris_image, center, size, (wtime + WIDTH / 2, HEIGHT / 2), (WIDTH, HEIGHT))# draw ship and spritesmy_ship.draw(canvas)a_rock.draw(canvas)a_missile.draw(canvas)# update ship and spritesmy_ship.update()a_rock.update()a_missile.update()

添加UI，显示所剩生命（Lives）和所得分数（Score）：

    # draw score and livescanvas.draw_text('Lives:'+ str(lives), (50,50), 28, "Red")canvas.draw_text('Score:'+ str(score), (625,50), 28, "Red")

4. 导入飞船、导弹、星石、星云等图片（这个步骤中的代码写在“创建飞船类”之前，我是按照功能的实现描述的）

在一开始先创建好图片信息类：

class ImageInfo:def __init__(self, center, size, radius = 0, lifespan = None, animated = False):self.center = centerself.size = sizeself.radius = radiusif lifespan:self.lifespan = lifespanelse:self.lifespan = float('inf')self.animated = animateddef get_center(self):return self.centerdef get_size(self):return self.sizedef get_radius(self):return self.radiusdef get_lifespan(self):return self.lifespandef get_animated(self):return self.animated#导入图片    
# art assets created by Kim Lathrop, may be freely re-used in non-commercial projects, please credit Kim# debris images - debris1_brown.png, debris2_brown.png, debris3_brown.png, debris4_brown.png
#碎片               debris1_blue.png, debris2_blue.png, debris3_blue.png, debris4_blue.png, debris_blend.png
debris_info = ImageInfo([320, 240], [640, 480])
debris_image = simplegui.load_image("http://commondatastorage.googleapis.com/codeskulptor-assets/lathrop/debris2_blue.png")
#星云
# nebula images - nebula_brown.png, nebula_blue.png
nebula_info = ImageInfo([400, 300], [800, 600])
nebula_image = simplegui.load_image("http://commondatastorage.googleapis.com/codeskulptor-assets/lathrop/nebula_blue.f2014.png")
#飞溅
# splash image
splash_info = ImageInfo([200, 150], [400, 300])
splash_image = simplegui.load_image("http://commondatastorage.googleapis.com/codeskulptor-assets/lathrop/splash.png")
#飞船
# ship image
ship_info = ImageInfo([45, 45], [90, 90], 35)
ship_image = simplegui.load_image("http://commondatastorage.googleapis.com/codeskulptor-assets/lathrop/double_ship.png")
#导弹
# missile image - shot1.png, shot2.png, shot3.png
missile_info = ImageInfo([5,5], [10, 10], 3, 50)
missile_image = simplegui.load_image("http://commondatastorage.googleapis.com/codeskulptor-assets/lathrop/shot2.png")
#小行星
# asteroid images - asteroid_blue.png, asteroid_brown.png, asteroid_blend.png
asteroid_info = ImageInfo([45, 45], [90, 90], 40)
asteroid_image = simplegui.load_image("http://commondatastorage.googleapis.com/codeskulptor-assets/lathrop/asteroid_blue.png")
#爆炸
# animated explosion - explosion_orange.png, explosion_blue.png, explosion_blue2.png, explosion_alpha.png
explosion_info = ImageInfo([64, 64], [128, 128], 17, 24, True)
explosion_image = simplegui.load_image("http://commondatastorage.googleapis.com/codeskulptor-assets/lathrop/explosion_alpha.png")
#声音
# sound assets purchased from sounddogs.com, please do not redistribute
soundtrack = simplegui.load_sound("http://commondatastorage.googleapis.com/codeskulptor-assets/sounddogs/soundtrack.mp3")
missile_sound = simplegui.load_sound("http://commondatastorage.googleapis.com/codeskulptor-assets/sounddogs/missile.mp3")
missile_sound.set_volume(.5)
ship_thrust_sound = simplegui.load_sound("http://commondatastorage.googleapis.com/codeskulptor-assets/sounddogs/thrust.mp3")
explosion_sound = simplegui.load_sound("http://commondatastorage.googleapis.com/codeskulptor-assets/sounddogs/explosion.mp3")# alternative upbeat soundtrack by composer and former IIPP student Emiel Stopler
# please do not redistribute without permission from Emiel at http://www.filmcomposer.nl
#soundtrack = simplegui.load_sound("https://storage.googleapis.com/codeskulptor-assets/ricerocks_theme.mp3")

设置基本函数

#角度转为向量
# helper functions to handle transformations
def angle_to_vector(ang):return [math.cos(ang), math.sin(ang)]
#p，q距离，(a^2+b^2)^0.5
def dist(p,q):return math.sqrt((p[0] - q[0]) ** 2+(p[1] - q[1]) ** 2)

5. 初始化画面设置与开始

# initialize frame
frame = simplegui.create_frame("Asteroids", WIDTH, HEIGHT)# initialize ship and two sprites
my_ship = Ship([WIDTH / 2, HEIGHT / 2], [0, 0], 0, ship_image, ship_info)
a_rock = Sprite([WIDTH / 3, HEIGHT / 3], [1, 1], 0, 0.05, asteroid_image, asteroid_info) #0.05秒旋转一下
a_missile = Sprite([2 * WIDTH / 3, 2 * HEIGHT / 3], [-1,1], 0, 0, missile_image, missile_info, missile_sound)# register handlers
frame.set_draw_handler(draw)
frame.set_keydown_handler(keydown)#添加键盘控制
frame.set_keyup_handler(keyup)
timer = simplegui.create_timer(1000.0, rock_spawner)# get things rolling
timer.start()
frame.start()

6. 游戏界面展示：