第八部分

settings.py

@@ -0,0 +1,48 @@
+class Settings():
+    """A class to store all settings for Alien Invasion."""
+
+    def __init__(self):
+        """Initialize the game's static settings."""
+        # Screen settings.
+        self.screen_width = 1200
+        self.screen_height = 800
+        self.bg_color = (230, 230, 230)
+        
+        # Ship settings.
+        self.ship_limit = 3
+            
+        # Bullet settings.
+        self.bullet_width = 3
+        self.bullet_height = 15
+        self.bullet_color = 60, 60, 60
+        self.bullets_allowed = 3
+        
+        # Alien settings.
+        self.fleet_drop_speed = 10
+            
+        # How quickly the game speeds up.
+        self.speedup_scale = 1.1
+        # How quickly the alien point values increase.
+        self.score_scale = 1.5
+    
+        self.initialize_dynamic_settings()
+
+    def initialize_dynamic_settings(self):
+        """Initialize settings that change throughout the game."""
+        self.ship_speed_factor = 1.5
+        self.bullet_speed_factor = 3
+        self.alien_speed_factor = 1
+        
+        # Scoring.
+        self.alien_points = 50
+    
+        # fleet_direction of 1 represents right, -1 represents left.
+        self.fleet_direction = 1
+        
+    def increase_speed(self):
+        """Increase speed settings and alien point values."""
+        self.ship_speed_factor *= self.speedup_scale
+        self.bullet_speed_factor *= self.speedup_scale
+        self.alien_speed_factor *= self.speedup_scale
+        
+        self.alien_points = int(self.alien_points * self.score_scale)