def __init__(self, x, y, batch):
self.position = euclid.Point2(x, y)
self.velocity = euclid.Point2(0, 0)
self.angle = math.pi/2
self.batch = batch
self.lines = batch.add(6, GL_LINES, primitives.SmoothLineGroup(),
('v2f', (0, 0) * 6),
('c4B', (255, 255, 255, 255) * 6))
self.ball_position = euclid.Point2(window.width/2, window.height/4)
self.ball_velocity = euclid.Point2(0, 0)
self.ball_lines = primitives.add_circle(batch, 0, 0, 20, (255, 255, 255, 255), 20)
self._ball_verts = list(self.ball_lines.vertices)
self._update_ball_verts()
self.join_active = False
self.join_line = None
self.joined = False
def update(self, dt):
self.angle += (keyboard[key.LEFT] - keyboard[key.RIGHT]) * math.pi * dt
r = euclid.Matrix3.new_rotate(self.angle)
if keyboard[key.UP]:
thrust = r * euclid.Vector2(600, 0)
else:
thrust = euclid.Vector2(0, 0)
# attempt join on spacebar press
s_b = self.position - self.ball_position
if keyboard[key.SPACE] and abs(s_b) < 100:
self.join_active = True
if not self.joined:
# simulation is just the ship
# apply thrust to the ship directly
thrust.y += GRAVITY
# now figure my new velocity
self.velocity += thrust * dt
# calculate new line endpoints
self.position += self.velocity * dt
else:
# simulation is of a rod with ship and one end and ball at other
n_v = s_b.normalized()
n_t = thrust.normalized()
# figure the linear acceleration, velocity & move
d = abs(n_v.dot(n_t))
lin = thrust * d
lin.y += GRAVITY
self.velocity += lin * dt
self.cog += self.velocity * dt
# now the angular acceleration
r90 = euclid.Matrix3.new_rotate(math.pi/2)
r_n_t = r90 * n_t
rd = n_v.dot(r_n_t)
self.ang_velocity -= abs(abs(thrust)) * rd * 0.0001
self.join_angle += self.ang_velocity * dt
# vector from center of gravity our to either end
ar = euclid.Matrix3.new_rotate(self.join_angle)
a_r = ar * euclid.Vector2(self.join_length/2, 0)
# set the ship & ball positions
self.position = self.cog + a_r
self.ball_position = self.cog - a_r
self._update_ball_verts()
if self.join_active:
if abs(s_b) >= 100 and not self.joined:
self.joined = True
h_s_b = s_b / 2
self.cog = self.position - h_s_b
self.join_angle = math.atan2(s_b.y, s_b.x)
self.join_length = abs(s_b)
# mass just doubled, so slow linear velocity down
self.velocity /= 2
# XXX and generate some initial angular velocity based on
# XXX ship current velocity
self.ang_velocity = 0
# render the join line
l = [
self.position.x, self.position.y,
self.ball_position.x, self.ball_position.y
]
if self.join_line:
self.join_line.vertices[:] = l
else:
self.join_line = self.batch.add(2, GL_LINES, primitives.SmoothLineGroup(),
('v2f', l), ('c4B', (255, 255, 255, 255) * 2))
# update the ship verts
bl = r * euclid.Point2(-25, 25)
t = r * euclid.Point2(25, 0)
br = r * euclid.Point2(-25, -25)
x, y = self.position
self.lines.vertices[:] = [
x+bl.x, y+bl.y, x+t.x, y+t.y,
x+t.x, y+t.y, x+br.x, y+br.y,
x+br.x, y+br.y, x+bl.x, y+bl.y,
]