week14.py

# Week 14: Explorer (Smooth Keyboard Control in Pygame Zero)
# Goal: Control a player with arrow keys using keyboard state checking
# New concept: keyboard object for smooth movement

WIDTH = 600
HEIGHT = 400

# Player position
x = WIDTH // 2
y = HEIGHT // 2
speed = 4  # Pixels to move per frame

# === UPDATE FUNCTION ===
def update():
    global x, y
    
    # Check keyboard state each frame
    # This allows smooth diagonal movement!
    if keyboard.left:
        x -= speed
    if keyboard.right:
        x += speed
    if keyboard.up:
        y -= speed
    if keyboard.down:
        y += speed
    
    # Keep player inside the screen (boundary checking)
    # max() ensures value doesn't go below minimum
    # min() ensures value doesn't go above maximum
    x = max(10, min(WIDTH - 10, x))
    y = max(10, min(HEIGHT - 10, y))

# === DRAW FUNCTION ===
def draw():
    screen.clear()
    screen.fill('darkblue')  # Background color
    
    # Instructions
    screen.draw.text("Explorer - Use arrow keys", (20, 20), color='white')
    
    # Draw player as white circle
    screen.draw.filled_circle((x, y), 10, "white")

# === KEY CONCEPTS ===
# 1. keyboard.left, keyboard.right, keyboard.up, keyboard.down
#    These are TRUE when key is held down
# 2. Checking multiple keys in same frame = diagonal movement
# 3. Boundary checking: max(min_val, min(max_val, current))
# 4. This feels smoother than on_key_down() events!