Start work on a pymunk physics engine front.

arcade/experimental/pymunk_physics_engine.py

@@ -0,0 +1,93 @@
+"""
+Pymunk Physics Engine
+"""
+
+import pymunk
+import math
+from arcade import Sprite
+from arcade import SpriteList
+
+class _PhysicsObject:
+    def __init__(self, body=None, shape=None):
+        self.body = body
+        self.shape = shape
+
+
+class PymunkPhysicsEngine:
+    """
+    Pymunk Physics Engine
+    """
+
+    DYNAMIC = pymunk.Body.DYNAMIC
+    STATIC = pymunk.Body.STATIC
+    KINEMATIC = pymunk.Body.KINEMATIC
+    MOMENT_INF = pymunk.inf
+
+    def __init__(self, gravity=(0,0)):
+        # -- Pymunk
+        self.space = pymunk.Space()
+        self.space.gravity = gravity
+        self.sprites = {}
+
+
+    def add_sprite(self,
+                   sprite: Sprite,
+                   mass: float=1,
+                   friction: float=0.2,
+                   moment=None,
+                   body_type=DYNAMIC,
+                   radius=0
+                   ):
+        if sprite in self.sprites:
+            print("Sprite already in added.")
+
+        if moment is None:
+            moment = pymunk.moment_for_box(mass, (sprite.width, sprite.height))
+
+        body = pymunk.Body(mass, moment, body_type=body_type)
+        body.position = pymunk.Vec2d(sprite.center_x, sprite.center_y)
+
+        scaled_poly = []
+        poly = sprite.get_hit_box()
+        for vert in poly:
+            scaled_vert = []
+            for coord in vert:
+                scaled_vert.append(coord * sprite.scale)
+            scaled_poly.append(scaled_vert)
+
+        shape = pymunk.Poly(body, scaled_poly, radius=radius)
+        shape.friction = friction
+
+        physics_object = _PhysicsObject(body, shape)
+        self.sprites[sprite] = physics_object
+
+        self.space.add(body, shape)
+
+    def add_sprite_list(self,
+                        sprite_list: SpriteList,
+                        mass: float = 1,
+                        friction: float = 0.2,
+                        moment=None,
+                        body_type=DYNAMIC
+                        ):
+
+        for sprite in sprite_list:
+            self.add_sprite(sprite, mass, friction, moment, body_type)
+
+    def resync_sprites(self):
+        for sprite in self.sprites:
+            physics_object = self.sprites[sprite]
+            sprite.center_x = physics_object.body.position.x
+            sprite.center_y = physics_object.body.position.y
+            sprite.angle = math.degrees(physics_object.body.angle)
+
+    def step(self, delta_time = 1/60.0):
+        # Update physics
+        # Use a constant time step, don't use delta_time
+        # See "Game loop / moving time forward"
+        # http://www.pymunk.org/en/latest/overview.html#game-loop-moving-time-forward
+        self.space.step(delta_time)
+
+    def apply_force(self, sprite, force):
+        physics_object = self.sprites[sprite]
+        physics_object.body.apply_force_at_local_point(force, (0, 0))

arcade/experimental/pymunk_test_1.py

@@ -0,0 +1,161 @@
+import arcade
+
+SCREEN_TITLE = "Starting Template Simple"
+SPRITE_SCALING_PLAYER = 0.5
+MOVEMENT_SPEED = 5
+PLAYER_MOVE_FORCE = 700
+
+SPRITE_IMAGE_SIZE = 128
+SPRITE_SIZE = int(SPRITE_IMAGE_SIZE * SPRITE_SCALING_PLAYER)
+
+SCREEN_WIDTH = SPRITE_SIZE * 20
+SCREEN_HEIGHT = SPRITE_SIZE * 15
+
+from arcade.experimental.pymunk_physics_engine import PymunkPhysicsEngine
+
+class MyWindow(arcade.Window):
+    def __init__(self, width, height, title):
+        super().__init__(width, height, title)
+
+        arcade.set_background_color(arcade.color.AMAZON)
+
+        self.player_list = None
+        self.wall_list = None
+        self.item_list = None
+        self.player_sprite = None
+        self.physics_engine = None
+
+        # Track the current state of what key is pressed
+        self.left_pressed = False
+        self.right_pressed = False
+        self.up_pressed = False
+        self.down_pressed = False
+
+    def setup(self):
+        # Create the sprite lists
+        self.player_list = arcade.SpriteList()
+        self.wall_list = arcade.SpriteList()
+        self.item_list = arcade.SpriteList()
+
+        # Set up the player
+        self.player_sprite = arcade.Sprite(":resources:images/animated_characters/female_person/femalePerson_idle.png",
+                                           SPRITE_SCALING_PLAYER)
+        self.player_sprite.center_x = 250
+        self.player_sprite.center_y = 250
+        self.player_list.append(self.player_sprite)
+
+        # Set up the walls
+        for x in range(0, SCREEN_WIDTH + 1, SPRITE_SIZE):
+            wall = arcade.Sprite(":resources:images/tiles/grassCenter.png",
+                                 SPRITE_SCALING_PLAYER)
+            wall.center_x = x
+            wall.center_y = 0
+            self.wall_list.append(wall)
+
+            wall = arcade.Sprite(":resources:images/tiles/grassCenter.png",
+                                 SPRITE_SCALING_PLAYER)
+            wall.center_x = x
+            wall.center_y = SCREEN_HEIGHT
+            self.wall_list.append(wall)
+
+        # Set up the walls
+        for y in range(SPRITE_SIZE, SCREEN_HEIGHT, SPRITE_SIZE):
+            wall = arcade.Sprite(":resources:images/tiles/grassCenter.png",
+                                 SPRITE_SCALING_PLAYER)
+            wall.center_x = 0
+            wall.center_y = y
+            self.wall_list.append(wall)
+
+            wall = arcade.Sprite(":resources:images/tiles/grassCenter.png",
+                                 SPRITE_SCALING_PLAYER)
+            wall.center_x = SCREEN_WIDTH
+            wall.center_y = y
+            self.wall_list.append(wall)
+
+        # Add some movable boxes
+        for x in range(SPRITE_SIZE * 3, SPRITE_SIZE * 6, SPRITE_SIZE):
+            item = arcade.Sprite(":resources:images/tiles/boxCrate.png",
+                                 SPRITE_SCALING_PLAYER)
+            item.center_x = x
+            item.center_y = 400
+            self.item_list.append(item)
+
+        # Create the physics engine
+        self.physics_engine = PymunkPhysicsEngine()
+        self.physics_engine.add_sprite(self.player_sprite, moment=PymunkPhysicsEngine.MOMENT_INF)
+
+        self.physics_engine.add_sprite_list(self.wall_list,
+                                            mass=1,
+                                            friction=0,
+                                            moment=None,
+                                            body_type=PymunkPhysicsEngine.STATIC)
+
+        self.physics_engine.add_sprite_list(self.item_list,
+                                            mass=1,
+                                            friction=0,
+                                            moment=None,
+                                            body_type=PymunkPhysicsEngine.DYNAMIC)
+
+
+    def on_key_press(self, key, modifiers):
+        """Called whenever a key is pressed. """
+
+        if key == arcade.key.UP:
+            self.up_pressed = True
+        elif key == arcade.key.DOWN:
+            self.down_pressed = True
+        elif key == arcade.key.LEFT:
+            self.left_pressed = True
+        elif key == arcade.key.RIGHT:
+            self.right_pressed = True
+
+    def on_key_release(self, key, modifiers):
+        """Called when the user releases a key. """
+
+        if key == arcade.key.UP:
+            self.up_pressed = False
+        elif key == arcade.key.DOWN:
+            self.down_pressed = False
+        elif key == arcade.key.LEFT:
+            self.left_pressed = False
+        elif key == arcade.key.RIGHT:
+            self.right_pressed = False
+
+    def on_update(self, delta_time):
+        """ Movement and game logic """
+
+        # Calculate speed based on the keys pressed
+        self.player_sprite.change_x = 0
+        self.player_sprite.change_y = 0
+
+        if self.up_pressed and not self.down_pressed:
+            force = (0, PLAYER_MOVE_FORCE)
+            self.physics_engine.apply_force(self.player_sprite, force)
+        elif self.down_pressed and not self.up_pressed:
+            force = (0, -PLAYER_MOVE_FORCE)
+            self.physics_engine.apply_force(self.player_sprite, force)
+        if self.left_pressed and not self.right_pressed:
+            self.player_sprite.change_x = -MOVEMENT_SPEED
+            force = (-PLAYER_MOVE_FORCE, 0)
+            self.physics_engine.apply_force(self.player_sprite, force)
+        elif self.right_pressed and not self.left_pressed:
+            force = (PLAYER_MOVE_FORCE, 0)
+            self.physics_engine.apply_force(self.player_sprite, force)
+
+        self.physics_engine.step()
+        self.physics_engine.resync_sprites()
+
+    def on_draw(self):
+        arcade.start_render()
+        self.wall_list.draw()
+        self.item_list.draw()
+        self.player_list.draw()
+
+def main():
+    window = MyWindow(SCREEN_WIDTH, SCREEN_HEIGHT, SCREEN_TITLE)
+    window.setup()
+    arcade.run()
+
+
+if __name__ == "__main__":
+    main()