pymunk_demo_platformer_05.py Full Listing¶
pymunk_demo_platformer_05.py¶
1"""
2Example of Pymunk Physics Engine Platformer
3"""
4import math
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
49class GameWindow(arcade.Window):
50 """ Main Window """
51
52 def __init__(self, width, height, title):
53 """ Create the variables """
54
55 # Init the parent class
56 super().__init__(width, height, title)
57
58 # Player sprite
59 self.player_sprite: Optional[arcade.Sprite] = None
60
61 # Sprite lists we need
62 self.player_list: Optional[arcade.SpriteList] = None
63 self.wall_list: Optional[arcade.SpriteList] = None
64 self.bullet_list: Optional[arcade.SpriteList] = None
65 self.item_list: Optional[arcade.SpriteList] = None
66
67 # Track the current state of what key is pressed
68 self.left_pressed: bool = False
69 self.right_pressed: bool = False
70
71 # Physics engine
72 self.physics_engine = Optional[arcade.PymunkPhysicsEngine]
73
74 # Set background color
75 arcade.set_background_color(arcade.color.AMAZON)
76
77 def setup(self):
78 """ Set up everything with the game """
79
80 # Create the sprite lists
81 self.player_list = arcade.SpriteList()
82 self.bullet_list = arcade.SpriteList()
83
84 # Read in the tiled map
85 map_name = "pymunk_test_map.tmx"
86 my_map = arcade.tilemap.read_tmx(map_name)
87
88 # Read in the map layers
89 self.wall_list = arcade.tilemap.process_layer(my_map, 'Platforms', SPRITE_SCALING_TILES)
90 self.item_list = arcade.tilemap.process_layer(my_map, 'Dynamic Items', SPRITE_SCALING_TILES)
91
92 # Create player sprite
93 self.player_sprite = arcade.Sprite(":resources:images/animated_characters/female_person/femalePerson_idle.png",
94 SPRITE_SCALING_PLAYER)
95 # Set player location
96 grid_x = 1
97 grid_y = 1
98 self.player_sprite.center_x = SPRITE_SIZE * grid_x + SPRITE_SIZE / 2
99 self.player_sprite.center_y = SPRITE_SIZE * grid_y + SPRITE_SIZE / 2
100 # Add to player sprite list
101 self.player_list.append(self.player_sprite)
102
103 # --- Pymunk Physics Engine Setup ---
104
105 # The default damping for every object controls the percent of velocity
106 # the object will keep each second. A value of 1.0 is no speed loss,
107 # 0.9 is 10% per second, 0.1 is 90% per second.
108 # For top-down games, this is basically the friction for moving objects.
109 # For platformers with gravity, this should probably be set to 1.0.
110 # Default value is 1.0 if not specified.
111 damping = DEFAULT_DAMPING
112
113 # Set the gravity. (0, 0) is good for outer space and top-down.
114 gravity = (0, -GRAVITY)
115
116 # Create the physics engine
117 self.physics_engine = arcade.PymunkPhysicsEngine(damping=damping,
118 gravity=gravity)
119
120 # Add the player.
121 # For the player, we set the damping to a lower value, which increases
122 # the damping rate. This prevents the character from traveling too far
123 # after the player lets off the movement keys.
124 # Setting the moment to PymunkPhysicsEngine.MOMENT_INF prevents it from
125 # rotating.
126 # Friction normally goes between 0 (no friction) and 1.0 (high friction)
127 # Friction is between two objects in contact. It is important to remember
128 # in top-down games that friction moving along the 'floor' is controlled
129 # by damping.
130 self.physics_engine.add_sprite(self.player_sprite,
131 friction=PLAYER_FRICTION,
132 mass=PLAYER_MASS,
133 moment=arcade.PymunkPhysicsEngine.MOMENT_INF,
134 collision_type="player",
135 max_horizontal_velocity=PLAYER_MAX_HORIZONTAL_SPEED,
136 max_vertical_velocity=PLAYER_MAX_VERTICAL_SPEED)
137
138 # Create the walls.
139 # By setting the body type to PymunkPhysicsEngine.STATIC the walls can't
140 # move.
141 # Movable objects that respond to forces are PymunkPhysicsEngine.DYNAMIC
142 # PymunkPhysicsEngine.KINEMATIC objects will move, but are assumed to be
143 # repositioned by code and don't respond to physics forces.
144 # Dynamic is default.
145 self.physics_engine.add_sprite_list(self.wall_list,
146 friction=WALL_FRICTION,
147 collision_type="wall",
148 body_type=arcade.PymunkPhysicsEngine.STATIC)
149
150 # Create the items
151 self.physics_engine.add_sprite_list(self.item_list,
152 friction=DYNAMIC_ITEM_FRICTION,
153 collision_type="item")
154
155 def on_key_press(self, key, modifiers):
156 """Called whenever a key is pressed. """
157 pass
158
159 def on_key_release(self, key, modifiers):
160 """Called when the user releases a key. """
161 pass
162
163 def on_update(self, delta_time):
164 """ Movement and game logic """
165 self.physics_engine.step()
166
167 def on_draw(self):
168 """ Draw everything """
169 arcade.start_render()
170 self.wall_list.draw()
171 self.bullet_list.draw()
172 self.item_list.draw()
173 self.player_list.draw()
174
175def main():
176 """ Main method """
177 window = GameWindow(SCREEN_WIDTH, SCREEN_HEIGHT, SCREEN_TITLE)
178 window.setup()
179 arcade.run()
180
181
182if __name__ == "__main__":
183 main()