pymunk_demo_platformer_05.py Full Listing

pymunk_demo_platformer_05.py
  1"""
  2Example of Pymunk Physics Engine Platformer
  3"""
  4
  5from typing import Optional
  6import arcade
  7
  8SCREEN_TITLE = "PyMunk Platformer"
  9
 10# How big are our image tiles?
 11SPRITE_IMAGE_SIZE = 128
 12
 13# Scale sprites up or down
 14SPRITE_SCALING_PLAYER = 0.5
 15SPRITE_SCALING_TILES = 0.5
 16
 17# Scaled sprite size for tiles
 18SPRITE_SIZE = int(SPRITE_IMAGE_SIZE * SPRITE_SCALING_PLAYER)
 19
 20# Size of grid to show on screen, in number of tiles
 21SCREEN_GRID_WIDTH = 25
 22SCREEN_GRID_HEIGHT = 15
 23
 24# Size of screen to show, in pixels
 25SCREEN_WIDTH = SPRITE_SIZE * SCREEN_GRID_WIDTH
 26SCREEN_HEIGHT = SPRITE_SIZE * SCREEN_GRID_HEIGHT
 27
 28# --- Physics forces. Higher number, faster accelerating.
 29
 30# Gravity
 31GRAVITY = 1500
 32
 33# Damping - Amount of speed lost per second
 34DEFAULT_DAMPING = 1.0
 35PLAYER_DAMPING = 0.4
 36
 37# Friction between objects
 38PLAYER_FRICTION = 1.0
 39WALL_FRICTION = 0.7
 40DYNAMIC_ITEM_FRICTION = 0.6
 41
 42# Mass (defaults to 1)
 43PLAYER_MASS = 2.0
 44
 45# Keep player from going too fast
 46PLAYER_MAX_HORIZONTAL_SPEED = 450
 47PLAYER_MAX_VERTICAL_SPEED = 1600
 48
 49
 50class GameWindow(arcade.Window):
 51    """Main Window"""
 52
 53    def __init__(self, width, height, title):
 54        """Create the variables"""
 55
 56        # Init the parent class
 57        super().__init__(width, height, title)
 58
 59        # Player sprite
 60        self.player_sprite: arcade.Sprite | None = None
 61
 62        # Sprite lists we need
 63        self.player_list: arcade.SpriteList | None = None
 64        self.wall_list: arcade.SpriteList | None = None
 65        self.bullet_list: arcade.SpriteList | None = None
 66        self.item_list: arcade.SpriteList | None = None
 67
 68        # Track the current state of what key is pressed
 69        self.left_pressed: bool = False
 70        self.right_pressed: bool = False
 71
 72        # Physics engine
 73        self.physics_engine: arcade.PymunkPhysicsEngine | None = None
 74
 75        # Set background color
 76        self.background_color = arcade.color.AMAZON
 77
 78    def setup(self):
 79        """Set up everything with the game"""
 80
 81        # Create the sprite lists
 82        self.player_list = arcade.SpriteList()
 83        self.bullet_list = arcade.SpriteList()
 84
 85        # Map name
 86        map_name = ":resources:/tiled_maps/pymunk_test_map.json"
 87
 88        # Load in TileMap
 89        tile_map = arcade.load_tilemap(map_name, SPRITE_SCALING_TILES)
 90
 91        # Pull the sprite layers out of the tile map
 92        self.wall_list = tile_map.sprite_lists["Platforms"]
 93        self.item_list = tile_map.sprite_lists["Dynamic Items"]
 94
 95        # Create player sprite
 96        self.player_sprite = arcade.Sprite(
 97            ":resources:images/animated_characters/female_person/femalePerson_idle.png",
 98            SPRITE_SCALING_PLAYER,
 99        )
100        # Set player location
101        grid_x = 1
102        grid_y = 1
103        self.player_sprite.center_x = SPRITE_SIZE * grid_x + SPRITE_SIZE / 2
104        self.player_sprite.center_y = SPRITE_SIZE * grid_y + SPRITE_SIZE / 2
105        # Add to player sprite list
106        self.player_list.append(self.player_sprite)
107
108        # --- Pymunk Physics Engine Setup ---
109
110        # The default damping for every object controls the percent of velocity
111        # the object will keep each second. A value of 1.0 is no speed loss,
112        # 0.9 is 10% per second, 0.1 is 90% per second.
113        # For top-down games, this is basically the friction for moving objects.
114        # For platformers with gravity, this should probably be set to 1.0.
115        # Default value is 1.0 if not specified.
116        damping = DEFAULT_DAMPING
117
118        # Set the gravity. (0, 0) is good for outer space and top-down.
119        gravity = (0, -GRAVITY)
120
121        # Create the physics engine
122        self.physics_engine = arcade.PymunkPhysicsEngine(damping=damping, gravity=gravity)
123
124        # Add the player.
125        # For the player, we set the damping to a lower value, which increases
126        # the damping rate. This prevents the character from traveling too far
127        # after the player lets off the movement keys.
128        # Setting the moment of inertia to PymunkPhysicsEngine.MOMENT_INF prevents it from
129        # rotating.
130        # Friction normally goes between 0 (no friction) and 1.0 (high friction)
131        # Friction is between two objects in contact. It is important to remember
132        # in top-down games that friction moving along the 'floor' is controlled
133        # by damping.
134        self.physics_engine.add_sprite(
135            self.player_sprite,
136            friction=PLAYER_FRICTION,
137            mass=PLAYER_MASS,
138            moment_of_inertia=arcade.PymunkPhysicsEngine.MOMENT_INF,
139            collision_type="player",
140            max_horizontal_velocity=PLAYER_MAX_HORIZONTAL_SPEED,
141            max_vertical_velocity=PLAYER_MAX_VERTICAL_SPEED,
142        )
143
144        # Create the walls.
145        # By setting the body type to PymunkPhysicsEngine.STATIC the walls can't
146        # move.
147        # Movable objects that respond to forces are PymunkPhysicsEngine.DYNAMIC
148        # PymunkPhysicsEngine.KINEMATIC objects will move, but are assumed to be
149        # repositioned by code and don't respond to physics forces.
150        # Dynamic is default.
151        self.physics_engine.add_sprite_list(
152            self.wall_list,
153            friction=WALL_FRICTION,
154            collision_type="wall",
155            body_type=arcade.PymunkPhysicsEngine.STATIC,
156        )
157
158        # Create the items
159        self.physics_engine.add_sprite_list(
160            self.item_list, friction=DYNAMIC_ITEM_FRICTION, collision_type="item"
161        )
162
163    def on_key_press(self, key, modifiers):
164        """Called whenever a key is pressed."""
165        pass
166
167    def on_key_release(self, key, modifiers):
168        """Called when the user releases a key."""
169        pass
170
171    def on_update(self, delta_time):
172        """Movement and game logic"""
173        self.physics_engine.step()
174
175    def on_draw(self):
176        """Draw everything"""
177        self.clear()
178        self.wall_list.draw()
179        self.bullet_list.draw()
180        self.item_list.draw()
181        self.player_list.draw()
182
183
184def main():
185    """Main function"""
186    window = GameWindow(SCREEN_WIDTH, SCREEN_HEIGHT, SCREEN_TITLE)
187    window.setup()
188    arcade.run()
189
190
191if __name__ == "__main__":
192    main()