def createBalls(win, nBalls, radius, boundRect, speed):
""" Create the balls to be put in the area """
halfX = (boundRect[0] + boundRect[2]) / 2.0
halfY = (boundRect[1] + boundRect[3]) / 2.0
# The four rectangles that build the main rectangle
rectanglesList = []
rectanglesList.append([boundRect[0], boundRect[1], halfX, halfY])
rectanglesList.append([halfX, boundRect[1], boundRect[2], halfY])
rectanglesList.append([boundRect[0], halfY, halfX, boundRect[3]])
rectanglesList.append([halfX, halfY, boundRect[2], boundRect[3]])
# Generate the balls in the
balls = []
from random import shuffle
from numpy.random import uniform
from common import Geometry
for i in range(0, nBalls):
startPos = np.array(
[uniform(
rectanglesList[
i % 4][0] + radius, rectanglesList[i % 4][2] - radius),
uniform(rectanglesList[i % 4][1] + radius, rectanglesList[i % 4][3] - radius)])
direction = Geometry.normalized(
np.array([uniform(-1, 1), uniform(-1, 1)]))
ball = Ball(win, position=startPos, direction=direction,
speed=speed, radius=radius, color='Black')
balls.append(ball)
shuffle(balls)
return balls, rectanglesList
def preGenerateTrajectories(ballSpeed, expInfo, allBallsList, rectangles,
repulsionStrength, edgerepulsionStrength,
centerAttraction):
"""
Precompute the trajectories of points
"""
trajClock = core.Clock()
trajClock.reset()
nFrames = int(expInfo['Duration'] / (1.0 / 60.0))
fullFrame = [None] * nFrames # preallocate space for the list
from common import Geometry
from numpy import array
for i in range(0, nFrames):
fullFrame[i] = dict()
for ballListID, ballList in allBallsList.iteritems():
boundingRectangle = rectangles[ballListID]
for ball1 in ballList:
force = array([0, 0])
for ball2 in ballList:
if (ball1 == ball2):
continue
# balls collide
delta = ((ball1.pos() - ball2.pos()))
dist2 = ((delta**2).sum())
force = force + repulsionStrength * \
(ball1.radius * ball2.radius) * delta / (dist2 * dist2)
# Repulsion to borders
force[0] = force[0] + edgerepulsionStrength / \
((boundingRectangle[0] - ball1.pos()[0]) ** 2)
force[0] = force[0] - edgerepulsionStrength / \
((boundingRectangle[2] - ball1.pos()[0]) ** 2)
force[1] = force[1] + edgerepulsionStrength / \
((boundingRectangle[1] - ball1.pos()[1]) ** 2)
force[1] = force[1] - edgerepulsionStrength / \
((boundingRectangle[3] - ball1.pos()[1]) ** 2)
# Add a little attraction to the center of boundingRectangle
dispFromCenter = Geometry.rectangleCenter(boundingRectangle)
force = force - (ball1.pos() - dispFromCenter)
ball1.direction = ball1.direction + centerAttraction * force
# Renormalize direction with correct speed
ball1.direction = Geometry.normalized(
ball1.direction) * ballSpeed
# Move the ball in the computed direction and finally draw it
ball1.move(ball1.direction)
# if (i==1): #print displacement for debug purpose
# print np.np.sqrt(np.dot(ball1.direction,ball1.direction))*60
fullFrame[i][ball1] = ball1.pos()
return fullFrame