皮蒙克物理引擎-联合构建器#
它使用Pymunk物理引擎来模拟具有关节的项目
pymunk_joint_builder.py#
1"""
2Pymunk 2
3
4If Python and Arcade are installed, this example can be run from the command line with:
5python -m arcade.examples.pymunk_joint_builder
6"""
7import arcade
8import pymunk
9import timeit
10import math
11
12SCREEN_WIDTH = 1200
13SCREEN_HEIGHT = 800
14SCREEN_TITLE = "Pymunk 2 Example"
15
16"""
17Key bindings:
18
191 - Drag mode
202 - Make box mode
213 - Make PinJoint mode
224 - Make DampedSpring mode
23
24S - No gravity or friction
25L - Layout, no gravity, lots of friction
26G - Gravity, little bit of friction
27
28Right-click, fire coin
29
30"""
31
32
33class PhysicsSprite(arcade.Sprite):
34 def __init__(self, pymunk_shape, filename):
35 super().__init__(filename, center_x=pymunk_shape.body.position.x, center_y=pymunk_shape.body.position.y)
36 self.pymunk_shape = pymunk_shape
37
38
39class CircleSprite(PhysicsSprite):
40 def __init__(self, pymunk_shape, filename):
41 super().__init__(pymunk_shape, filename)
42 self.width = pymunk_shape.radius * 4
43 self.height = pymunk_shape.radius * 4
44
45
46class BoxSprite(PhysicsSprite):
47 def __init__(self, pymunk_shape, filename, width, height):
48 super().__init__(pymunk_shape, filename)
49 self.width = width
50 self.height = height
51
52
53class MyApplication(arcade.Window):
54 """ Main application class. """
55
56 def __init__(self, width, height, title):
57 super().__init__(width, height, title)
58
59 self.background_color = arcade.color.DARK_SLATE_GRAY
60
61 # -- Pymunk
62 self.space = pymunk.Space()
63 self.space.gravity = (0.0, -900.0)
64
65 # Lists of sprites or lines
66 self.sprite_list: arcade.SpriteList[PhysicsSprite] = arcade.SpriteList()
67 self.static_lines = []
68
69 # Used for dragging shapes around with the mouse
70 self.shape_being_dragged = None
71 self.last_mouse_position = 0, 0
72
73 self.processing_time_text = None
74 self.draw_time_text = None
75 self.draw_mode_text = None
76 self.shape_1 = None
77 self.shape_2 = None
78 self.draw_time = 0
79 self.processing_time = 0
80 self.joints = []
81
82 self.physics = "Normal"
83 self.mode = "Make Box"
84
85 # Create the floor
86 self.floor_height = 80
87 body = pymunk.Body(body_type=pymunk.Body.STATIC)
88 shape = pymunk.Segment(body, (0, self.floor_height), (SCREEN_WIDTH, self.floor_height), 0.0)
89 shape.friction = 10
90 self.space.add(shape, body)
91 self.static_lines.append(shape)
92
93 def on_draw(self):
94 """
95 Render the screen.
96 """
97
98 # This command has to happen before we start drawing
99 self.clear()
100
101 # Start timing how long this takes
102 draw_start_time = timeit.default_timer()
103
104 # Draw all the sprites
105 self.sprite_list.draw()
106
107 # Draw the lines that aren't sprites
108 for line in self.static_lines:
109 body = line.body
110
111 pv1 = body.position + line.a.rotated(body.angle)
112 pv2 = body.position + line.b.rotated(body.angle)
113 arcade.draw_line(pv1.x, pv1.y, pv2.x, pv2.y, arcade.color.WHITE, 2)
114
115 for joint in self.joints:
116 color = arcade.color.WHITE
117 if isinstance(joint, pymunk.DampedSpring):
118 color = arcade.color.DARK_GREEN
119 arcade.draw_line(joint.a.position.x,
120 joint.a.position.y,
121 joint.b.position.x,
122 joint.b.position.y,
123 color, 3)
124
125 # arcade.draw_text(output, 10, 20, arcade.color.WHITE, 14)
126 # Display timings
127 output = f"Processing time: {self.processing_time:.3f}"
128 arcade.draw_text(output, 20, SCREEN_HEIGHT - 20, arcade.color.WHITE)
129
130 output = f"Drawing time: {self.draw_time:.3f}"
131 arcade.draw_text(output, 20, SCREEN_HEIGHT - 40, arcade.color.WHITE)
132
133 self.draw_time = timeit.default_timer() - draw_start_time
134
135 output = f"Mode: {self.mode}"
136 arcade.draw_text(output, 20, SCREEN_HEIGHT - 60, arcade.color.WHITE)
137
138 output = f"Physics: {self.physics}"
139 arcade.draw_text(output, 20, SCREEN_HEIGHT - 80, arcade.color.WHITE)
140
141 def make_box(self, x, y):
142 size = 45
143 mass = 12.0
144 moment = pymunk.moment_for_box(mass, (size, size))
145 body = pymunk.Body(mass, moment)
146 body.position = pymunk.Vec2d(x, y)
147 shape = pymunk.Poly.create_box(body, (size, size))
148 shape.friction = 0.3
149 self.space.add(body, shape)
150
151 sprite = BoxSprite(shape, ":resources:images/tiles/boxCrate_double.png", width=size, height=size)
152 self.sprite_list.append(sprite)
153
154 def make_circle(self, x, y):
155 size = 20
156 mass = 12.0
157 moment = pymunk.moment_for_circle(mass, 0, size, (0, 0))
158 body = pymunk.Body(mass, moment)
159 body.position = pymunk.Vec2d(x, y)
160 shape = pymunk.Circle(body, size, pymunk.Vec2d(0, 0))
161 shape.friction = 0.3
162 self.space.add(body, shape)
163
164 sprite = CircleSprite(shape, ":resources:images/items/coinGold.png")
165 self.sprite_list.append(sprite)
166
167 def make_pin_joint(self, x, y):
168 shape_selected = self.get_shape(x, y)
169 if shape_selected is None:
170 return
171
172 if self.shape_1 is None:
173 print("Shape 1 Selected")
174 self.shape_1 = shape_selected
175 elif self.shape_2 is None:
176 print("Shape 2 Selected")
177 self.shape_2 = shape_selected
178 joint = pymunk.PinJoint(self.shape_1.shape.body, self.shape_2.shape.body)
179 self.space.add(joint)
180 self.joints.append(joint)
181 self.shape_1 = None
182 self.shape_2 = None
183 print("Joint Made")
184
185 def make_damped_spring(self, x, y):
186 shape_selected = self.get_shape(x, y)
187 if shape_selected is None:
188 return
189
190 if self.shape_1 is None:
191 print("Shape 1 Selected")
192 self.shape_1 = shape_selected
193 elif self.shape_2 is None:
194 print("Shape 2 Selected")
195 self.shape_2 = shape_selected
196 joint = pymunk.DampedSpring(self.shape_1.shape.body, self.shape_2.shape.body, (0, 0), (0, 0), 45, 300, 30)
197 self.space.add(joint)
198 self.joints.append(joint)
199 self.shape_1 = None
200 self.shape_2 = None
201 print("Joint Made")
202
203 def get_shape(self, x, y):
204 # See if we clicked on anything
205 shape_list = self.space.point_query((x, y), 1, pymunk.ShapeFilter())
206
207 # If we did, remember what we clicked on
208 if len(shape_list) > 0:
209 shape = shape_list[0]
210 else:
211 shape = None
212
213 return shape
214
215 def on_mouse_press(self, x, y, button, modifiers):
216
217 if button == 1 and self.mode == "Drag":
218 self.last_mouse_position = x, y
219 self.shape_being_dragged = self.get_shape(x, y)
220
221 elif button == 1 and self.mode == "Make Box":
222 self.make_box(x, y)
223
224 elif button == 1 and self.mode == "Make Circle":
225 self.make_circle(x, y)
226
227 elif button == 1 and self.mode == "Make PinJoint":
228 self.make_pin_joint(x, y)
229
230 elif button == 1 and self.mode == "Make DampedSpring":
231 self.make_damped_spring(x, y)
232
233 elif button == 4:
234 # With right mouse button, shoot a heavy coin fast.
235 mass = 60
236 radius = 10
237 inertia = pymunk.moment_for_circle(mass, 0, radius, (0, 0))
238 body = pymunk.Body(mass, inertia)
239 body.position = x, y
240 body.velocity = 2000, 0
241 shape = pymunk.Circle(body, radius, pymunk.Vec2d(0, 0))
242 shape.friction = 0.3
243 self.space.add(body, shape)
244
245 sprite = CircleSprite(shape, ":resources:images/items/coinGold.png")
246 self.sprite_list.append(sprite)
247
248 def on_mouse_release(self, x, y, button, modifiers):
249 if button == 1:
250 # Release the item we are holding (if any)
251 self.shape_being_dragged = None
252
253 def on_mouse_motion(self, x, y, dx, dy):
254 if self.shape_being_dragged is not None:
255 # If we are holding an object, move it with the mouse
256 self.last_mouse_position = x, y
257 self.shape_being_dragged.shape.body.position = self.last_mouse_position
258 self.shape_being_dragged.shape.body.velocity = dx * 20, dy * 20
259
260 def on_key_press(self, symbol: int, modifiers: int):
261 if symbol == arcade.key.KEY_1:
262 self.mode = "Drag"
263 elif symbol == arcade.key.KEY_2:
264 self.mode = "Make Box"
265 elif symbol == arcade.key.KEY_3:
266 self.mode = "Make Circle"
267
268 elif symbol == arcade.key.KEY_4:
269 self.mode = "Make PinJoint"
270 elif symbol == arcade.key.KEY_5:
271 self.mode = "Make DampedSpring"
272
273 elif symbol == arcade.key.S:
274 self.space.gravity = (0.0, 0.0)
275 self.space.damping = 1
276 self.physics = "Outer Space"
277 elif symbol == arcade.key.L:
278 self.space.gravity = (0.0, 0.0)
279 self.space.damping = 0
280 self.physics = "Layout"
281 elif symbol == arcade.key.G:
282 self.space.damping = 0.95
283 self.space.gravity = (0.0, -900.0)
284 self.physics = "Normal"
285
286 def on_update(self, delta_time):
287 start_time = timeit.default_timer()
288
289 # Check for balls that fall off the screen
290 for sprite in self.sprite_list:
291 if sprite.pymunk_shape.body.position.y < 0:
292 # Remove balls from physics space
293 self.space.remove(sprite.pymunk_shape, sprite.pymunk_shape.body)
294 # Remove balls from physics list
295 sprite.kill()
296
297 # Update physics
298 self.space.step(1 / 80.0)
299
300 # If we are dragging an object, make sure it stays with the mouse. Otherwise
301 # gravity will drag it down.
302 if self.shape_being_dragged is not None:
303 self.shape_being_dragged.shape.body.position = self.last_mouse_position
304 self.shape_being_dragged.shape.body.velocity = 0, 0
305
306 # Move sprites to where physics objects are
307 for sprite in self.sprite_list:
308 sprite.center_x = sprite.pymunk_shape.body.position.x
309 sprite.center_y = sprite.pymunk_shape.body.position.y
310 # Reverse angle because pymunk rotates ccw
311 sprite.angle = -math.degrees(sprite.pymunk_shape.body.angle)
312
313 # Save the time it took to do this.
314 self.processing_time = timeit.default_timer() - start_time
315
316
317def main():
318 window = MyApplication(SCREEN_WIDTH, SCREEN_HEIGHT, SCREEN_TITLE)
319 window.run()
320
321
322if __name__ == "__main__":
323 main()