第 2 周：构建互动游戏

第三课：游戏物理与运动

3.1 理解游戏物理

游戏物理涉及模拟现实世界的物理，使游戏更加真实和引人入胜。速度、加速度和重力等基本物理原理可以使游戏中的动作和交互感觉自然。

3.1.1 速度和加速度

• 速度是物体位置的变化率。
• 加速度是速度的变化率。

示例：基本速度运动

import pygame

# Initialize Pygame
pygame.init()

# Screen setup
screen = pygame.display.set_mode((800, 600))
pygame.display.set_caption("Basic Movement with Velocity")

# Colors
white = (255, 255, 255)
black = (0, 0, 0)

# Player setup
player = pygame.Rect(375, 275, 50, 50)
velocity = pygame.Vector2(0, 0)

# Main game loop
running = True
while running:
    for event in pygame.event.get():
        if event.type == pygame.QUIT:
            running = False

    # Keyboard input for movement
    keys = pygame.key.get_pressed()
    if keys[pygame.K_LEFT]:
        velocity.x = -5
    elif keys[pygame.K_RIGHT]:
        velocity.x = 5
    else:
        velocity.x = 0

    if keys[pygame.K_UP]:
        velocity.y = -5
    elif keys[pygame.K_DOWN]:
        velocity.y = 5
    else:
        velocity.y = 0

    # Update player position
    player.move_ip(velocity)

    # Clear screen
    screen.fill(white)

    # Draw player
    pygame.draw.rect(screen, black, player)

    # Update display
    pygame.display.flip()

pygame.quit()

3.1.2 重力模拟

重力通过向下拉物体来模拟地球上的重力效果，从而为游戏增添真实感。

示例：向下落物体添加重力

import pygame

# Initialize Pygame
pygame.init()

# Screen setup
screen = pygame.display.set_mode((800, 600))
pygame.display.set_caption("Gravity Simulation")

# Colors
white = (255, 255, 255)
black = (0, 0, 0)

# Object setup
object = pygame.Rect(375, 50, 50, 50)
gravity = 0.5
velocity_y = 0

# Main game loop
running = True
while running:
    for event in pygame.event.get():
        if event.type == pygame.QUIT:
            running = False

    # Apply gravity
    velocity_y  = gravity
    object.y  = velocity_y

    # Reset object position if it falls off-screen
    if object.y > 600:
        object.y = 50
        velocity_y = 0

    # Clear screen
    screen.fill(white)

    # Draw object
    pygame.draw.rect(screen, black, object)

    # Update display
    pygame.display.flip()

pygame.quit()

3.2 物体的弹跳和反射

要创建动态游戏，通常需要模拟弹跳物体，例如从墙壁反弹的球。

示例：弹跳球模拟

import pygame

# Initialize Pygame
pygame.init()

# Screen setup
screen = pygame.display.set_mode((800, 600))
pygame.display.set_caption("Bouncing Ball")

# Colors
white = (255, 255, 255)
black = (0, 0, 0)

# Ball setup
ball = pygame.Rect(375, 275, 50, 50)
velocity = pygame.Vector2(4, 4)

# Main game loop
running = True
while running:
    for event in pygame.event.get():
        if event.type == pygame.QUIT:
            running = False

    # Move ball
    ball.move_ip(velocity)

    # Bounce off walls
    if ball.left = 800:
        velocity.x = -velocity.x
    if ball.top = 600:
        velocity.y = -velocity.y

    # Clear screen
    screen.fill(white)

    # Draw ball
    pygame.draw.ellipse(screen, black, ball)

    # Update display
    pygame.display.flip()

pygame.quit()

3.3 迷你项目：弹跳球游戏

目标： 创建一个游戏，球在屏幕上弹跳，撞到墙壁时改变方向。

3.3.1 代码示例

import pygame

# Initialize Pygame
pygame.init()

# Screen setup
screen = pygame.display.set_mode((800, 600))
pygame.display.set_caption("Bouncing Ball Game")

# Colors
white = (255, 255, 255)
black = (0, 0, 0)

# Ball setup
ball = pygame.Rect(375, 275, 50, 50)
velocity = pygame.Vector2(3, 3)

# Main game loop
running = True
while running:
    for event in pygame.event.get():
        if event.type == pygame.QUIT:
            running = False

    # Move ball
    ball.move_ip(velocity)

    # Bounce off walls
    if ball.left = 800:
        velocity.x = -velocity.x
    if ball.top = 600:
        velocity.y = -velocity.y

    # Clear screen
    screen.fill(white)

    # Draw ball
    pygame.draw.ellipse(screen, black, ball)

    # Update display
    pygame.display.flip()

pygame.quit()

3.4 练习

1. 添加障碍：
   • 引入球可以弹开的固定障碍物。
2. 更改球颜色：
   • 让球每次从墙上弹起时改变颜色。

第 4 课：使用声音和音乐

4.1 添加音效和音乐

音效和音乐对于创造身临其境的游戏体验至关重要。 Pygame 允许您轻松地为游戏添加声音。

4.1.1 加载和播放声音

• 要在Pygame中使用声音，您必须首先加载声音文件，然后播放它。

示例：添加音效

import pygame

# Initialize Pygame and Mixer
pygame.init()
pygame.mixer.init()

# Load sound effect
bounce_sound = pygame.mixer.Sound("bounce.wav")

# Screen setup
screen = pygame.display.set_mode((800, 600))
pygame.display.set_caption("Sound Effects")

# Colors
white = (255, 255, 255)
black = (0, 0, 0)

# Ball setup
ball = pygame.Rect(375, 275, 50, 50)
velocity = pygame.Vector2(3, 3)

# Main game loop
running = True
while running:
    for event in pygame.event.get():
        if event.type == pygame.QUIT:
            running = False

    # Move ball
    ball.move_ip(velocity)

    # Bounce off walls and play sound
    if ball.left = 800:
        velocity.x = -velocity.x
        bounce_sound.play()  # Play sound on bounce
    if ball.top = 600:
        velocity.y = -velocity.y
        bounce_sound.play()

    # Clear screen
    screen.fill(white)

    # Draw ball
    pygame.draw.ellipse(screen, black, ball)

    # Update display
    pygame.display.flip()

pygame.quit()

4.1.2 背景音乐

• 您还可以添加游戏过程中持续播放的背景音乐。

示例：添加背景音乐

import pygame

# Initialize Pygame and Mixer
pygame.init()
pygame.mixer.init()

# Load and play background music
pygame.mixer.music.load("background_music.mp3")
pygame.mixer.music.play(-1)  # Loop indefinitely

# Screen setup
screen = pygame.display.set_mode((800, 600))
pygame.display.set_caption("Background Music")

# Colors
white = (255, 255, 255)
black = (0, 0, 0)

# Main game loop
running = True
while running:
    for event in pygame.event.get():
        if event.type == pygame.QUIT:
            running = False

    # Clear screen
    screen.fill(white)

    # Update display
    pygame.display.flip()

pygame.quit()

4.2 根据事件触发声音

音效可以根据特定的游戏事件触发，例如碰撞或玩家动作。

示例：声音记忆游戏

python
import pygame
import random

# Initialize Pygame and Mixer
pygame.init()
pygame.mixer.init()

# Load sounds
sounds = [pygame.mixer.Sound(f"sound{i}.wav") for i in range(4)]

# Screen setup
screen = pygame.display.set_mode((800, 600))
pygame.display.set_caption("Sound Memory Game")

# Colors
white = (255, 255, 255)
black = (0, 0, 0)

# Generate random sequence of sounds
sequence = [random.choice(sounds) for _ in range(5)]
current_step = 0

# Main game loop
running = True
while running: