def sprite_rect_vector(sprite, rect):
ball_vec = Vec2d(sprite.body.position.x, sprite.body.position.y)
rect_x = (rect[0] + rect[2]) / 2
rect_y = (rect[1] + rect[3]) / 2
rect_vec = Vec2d(rect_x, rect_y)
return Vec2d.normalized(ball_vec - rect_vec)
def __init__(self,
tile_centers,
tile_vertices,
constraints,
pattern_center,
params,
hull_vertices,
screen,
damping=.6,
iterations=20):
self.params = params
self.space = pm.Space()
self.space.damping = damping
self.space.iterations = iterations
self.mouse = pm.Body(body_type=pm.Body.KINEMATIC)
self.tile_centers = tile_centers
self.tile_vertices = tile_vertices
self.constraints = constraints
self.hull_vertices = hull_vertices
self.pattern_center = pattern_center
self.selected = None
self.static_pins = []
self.max_scr = 1
self.center_bodies = []
self.center_shapes = []
self.tile_pinjoints = []
self.expansion_springs = []
self.reset()
self.handler = EventHandler(self)
self.screen = screen
_, self.height = self.screen.get_size()
# add bodies and shapes to centers of tiles
for i in range(len(self.tile_centers)):
(node_x, node_y) = self.tile_centers[i]
mass = 10
moment = pm.moment_for_poly(mass, self.tile_vertices[i])
body = pm.Body(mass, moment)
body.position = (node_x, node_y)
body.start_position = Vec2d(body.position)
shape = pm.Poly(
body,
list(
map(lambda x: ((x[0] - node_x) * 1, (x[1] - node_y) * 1),
self.tile_vertices[i])))
shape.elasticity = 0
self.space.add(body, shape)
self.center_bodies.append(body)
self.center_shapes.append(shape)
# add shapes at vertices that do not generate collisions
self.vertex_bodies = []
self.vertex_shapes = []
for i in range(len(self.tile_vertices)):
self.vertex_bodies.append([])
self.vertex_shapes.append([])
for (node_x, node_y) in self.tile_vertices[i]:
mass = 1
radius = 5
moment = pm.moment_for_circle(mass, 0, radius, (0, 0))
body = pm.Body(mass, moment)
body.position = (node_x, node_y)
body.start_position = Vec2d(body.position)
self.vertex_bodies[-1].append(body)
shape = pm.Circle(body, 5)
shape.sensor = True
self.vertex_shapes[-1].append(shape)
self.space.add(body, shape)
pj = pm.PinJoint(self.center_bodies[i], body,
(node_x - self.tile_centers[i][0],
node_y - self.tile_centers[i][1]), (0, 0))
self.space.add(pj)
# add kirigami connection pins to link tiles together as specified in constraints
for c in self.constraints:
a = self.center_bodies[(c[0])]
b = self.center_bodies[(c[2])]
pin = pm.PinJoint(
a, b, (self.tile_vertices[(c[0])][(c[1])][0] - a.position.x,
self.tile_vertices[(c[0])][(c[1])][1] - a.position.y),
(self.tile_vertices[(c[2])][(c[3])][0] - b.position.x,
self.tile_vertices[(c[2])][(c[3])][1] - b.position.y))
self.space.add(pin)
self.tile_pinjoints.append(pin)
# if AUTO_EXPAND, add springs pulling hull tiles outward
if self.params['AUTO_EXPAND'] or self.params['CALCULATE_AREA_PERIM']:
self.hull_tiles = list(set(list(zip(*(self.hull_vertices)))[0]))
if self.params['AUTO_EXPAND']:
spring_circle_radius = 500
for t in self.hull_tiles:
body = self.center_bodies[t]
if body.position != self.pattern_center:
self.spring_anchor_coords = (
Vec2d.normalized(body.position -
Vec2d(self.pattern_center)) *
spring_circle_radius) + Vec2d(self.pattern_center)
ds = pm.DampedSpring(body, self.space.static_body, (0, 0),
self.spring_anchor_coords, 0,
self.params['SPRING_STIFFNESS'],
self.params['SPRING_DAMPING'])
self.space.add(ds)
self.expansion_springs.append(ds)
else:
print(
"Auto-Expansion Note: There was a tile center point lying on the pattern center, which the simulation did not attach an expanding spring to."
)
self.reset()
