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
49# Force applied while on the ground
50PLAYER_MOVE_FORCE_ON_GROUND = 8000
51
52# Force applied when moving left/right in the air
53PLAYER_MOVE_FORCE_IN_AIR = 900
54
55# Strength of a jump
56PLAYER_JUMP_IMPULSE = 1800
57
58class GameWindow(arcade.Window):
59 """ Main Window """
60
61 def __init__(self, width, height, title):
62 """ Create the variables """
63
64 # Init the parent class
65 super().__init__(width, height, title)
66
67 # Player sprite
68 self.player_sprite: Optional[arcade.Sprite] = None
69
70 # Sprite lists we need
71 self.player_list: Optional[arcade.SpriteList] = None
72 self.wall_list: Optional[arcade.SpriteList] = None
73 self.bullet_list: Optional[arcade.SpriteList] = None
74 self.item_list: Optional[arcade.SpriteList] = None
75
76 # Track the current state of what key is pressed
77 self.left_pressed: bool = False
78 self.right_pressed: bool = False
79
80 # Physics engine
81 self.physics_engine = Optional[arcade.PymunkPhysicsEngine]
82
83 # Set background color
84 arcade.set_background_color(arcade.color.AMAZON)
85
86 def setup(self):
87 """ Set up everything with the game """
88
89 # Create the sprite lists
90 self.player_list = arcade.SpriteList()
91 self.bullet_list = arcade.SpriteList()
92
93 # Read in the tiled map
94 map_name = "pymunk_test_map.tmx"
95 my_map = arcade.tilemap.read_tmx(map_name)
96
97 # Read in the map layers
98 self.wall_list = arcade.tilemap.process_layer(my_map, 'Platforms', SPRITE_SCALING_TILES)
99 self.item_list = arcade.tilemap.process_layer(my_map, 'Dynamic Items', SPRITE_SCALING_TILES)
100
101 # Create player sprite
102 self.player_sprite = arcade.Sprite(":resources:images/animated_characters/female_person/femalePerson_idle.png",
103 SPRITE_SCALING_PLAYER)
104 # Set player location
105 grid_x = 1
106 grid_y = 1
107 self.player_sprite.center_x = SPRITE_SIZE * grid_x + SPRITE_SIZE / 2
108 self.player_sprite.center_y = SPRITE_SIZE * grid_y + SPRITE_SIZE / 2
109 # Add to player sprite list
110 self.player_list.append(self.player_sprite)
111
112 # --- Pymunk Physics Engine Setup ---
113
114 # The default damping for every object controls the percent of velocity
115 # the object will keep each second. A value of 1.0 is no speed loss,
116 # 0.9 is 10% per second, 0.1 is 90% per second.
117 # For top-down games, this is basically the friction for moving objects.
118 # For platformers with gravity, this should probably be set to 1.0.
119 # Default value is 1.0 if not specified.
120 damping = DEFAULT_DAMPING
121
122 # Set the gravity. (0, 0) is good for outer space and top-down.
123 gravity = (0, -GRAVITY)
124
125 # Create the physics engine
126 self.physics_engine = arcade.PymunkPhysicsEngine(damping=damping,
127 gravity=gravity)
128
129 # Add the player.
130 # For the player, we set the damping to a lower value, which increases
131 # the damping rate. This prevents the character from traveling too far
132 # after the player lets off the movement keys.
133 # Setting the moment to PymunkPhysicsEngine.MOMENT_INF prevents it from
134 # rotating.
135 # Friction normally goes between 0 (no friction) and 1.0 (high friction)
136 # Friction is between two objects in contact. It is important to remember
137 # in top-down games that friction moving along the 'floor' is controlled
138 # by damping.
139 self.physics_engine.add_sprite(self.player_sprite,
140 friction=PLAYER_FRICTION,
141 mass=PLAYER_MASS,
142 moment=arcade.PymunkPhysicsEngine.MOMENT_INF,
143 collision_type="player",
144 max_horizontal_velocity=PLAYER_MAX_HORIZONTAL_SPEED,
145 max_vertical_velocity=PLAYER_MAX_VERTICAL_SPEED)
146
147 # Create the walls.
148 # By setting the body type to PymunkPhysicsEngine.STATIC the walls can't
149 # move.
150 # Movable objects that respond to forces are PymunkPhysicsEngine.DYNAMIC
151 # PymunkPhysicsEngine.KINEMATIC objects will move, but are assumed to be
152 # repositioned by code and don't respond to physics forces.
153 # Dynamic is default.
154 self.physics_engine.add_sprite_list(self.wall_list,
155 friction=WALL_FRICTION,
156 collision_type="wall",
157 body_type=arcade.PymunkPhysicsEngine.STATIC)
158
159 # Create the items
160 self.physics_engine.add_sprite_list(self.item_list,
161 friction=DYNAMIC_ITEM_FRICTION,
162 collision_type="item")
163
164 def on_key_press(self, key, modifiers):
165 """Called whenever a key is pressed. """
166
167 if key == arcade.key.LEFT:
168 self.left_pressed = True
169 elif key == arcade.key.RIGHT:
170 self.right_pressed = True
171 elif key == arcade.key.UP:
172 # find out if player is standing on ground
173 if self.physics_engine.is_on_ground(self.player_sprite):
174 # She is! Go ahead and jump
175 impulse = (0, PLAYER_JUMP_IMPULSE)
176 self.physics_engine.apply_impulse(self.player_sprite, impulse)
177
178 def on_key_release(self, key, modifiers):
179 """Called when the user releases a key. """
180
181 if key == arcade.key.LEFT:
182 self.left_pressed = False
183 elif key == arcade.key.RIGHT:
184 self.right_pressed = False
185
186 def on_update(self, delta_time):
187 """ Movement and game logic """
188
189 is_on_ground = self.physics_engine.is_on_ground(self.player_sprite)
190 # Update player forces based on keys pressed
191 if self.left_pressed and not self.right_pressed:
192 # Create a force to the left. Apply it.
193 if is_on_ground:
194 force = (-PLAYER_MOVE_FORCE_ON_GROUND, 0)
195 else:
196 force = (-PLAYER_MOVE_FORCE_IN_AIR, 0)
197 self.physics_engine.apply_force(self.player_sprite, force)
198 # Set friction to zero for the player while moving
199 self.physics_engine.set_friction(self.player_sprite, 0)
200 elif self.right_pressed and not self.left_pressed:
201 # Create a force to the right. Apply it.
202 if is_on_ground:
203 force = (PLAYER_MOVE_FORCE_ON_GROUND, 0)
204 else:
205 force = (PLAYER_MOVE_FORCE_IN_AIR, 0)
206 self.physics_engine.apply_force(self.player_sprite, force)
207 # Set friction to zero for the player while moving
208 self.physics_engine.set_friction(self.player_sprite, 0)
209 else:
210 # Player's feet are not moving. Therefore up the friction so we stop.
211 self.physics_engine.set_friction(self.player_sprite, 1.0)
212
213 # Move items in the physics engine
214 self.physics_engine.step()
215
216 def on_draw(self):
217 """ Draw everything """
218 arcade.start_render()
219 self.wall_list.draw()
220 self.bullet_list.draw()
221 self.item_list.draw()
222 self.player_list.draw()
223
224def main():
225 """ Main method """
226 window = GameWindow(SCREEN_WIDTH, SCREEN_HEIGHT, SCREEN_TITLE)
227 window.setup()
228 arcade.run()
229
230
231if __name__ == "__main__":
232 main()