def main():
pygame.init()
SCREEN_WIDTH = 800
SCREEN_HEIGHT = 600
SCALE = 80 # pixels per meter
WIDTH = SCREEN_WIDTH/SCALE
HEIGHT = SCREEN_HEIGHT/SCALE
SCREEN_CENTRE = Point(WIDTH/2, HEIGHT/2)
CENTRE = SCREEN_CENTRE/SCALE
DISPLAY = pygame.display.set_mode((SCREEN_WIDTH, SCREEN_HEIGHT))
CLOCK = pygame.time.Clock()
totalTime = 0
GRAVITY = 9.81
helper = Helper(DISPLAY, SCALE, WIDTH, HEIGHT)
drawPos = helper.drawPos
worldPos = helper.worldPos
drawVector = helper.drawVector
personImage = pygame.image.load(os.getcwd()+"/person.jpg")
personRect = personImage.get_rect()
personImage = pygame.transform.scale(personImage, (int(personRect.width*(int(1.8*SCALE)/personRect.height)), int(1.8*SCALE)))
moveData = {
"lastPos": Point(),
"currentPos": Point(CENTRE.x, 0),
"lastScreenMousePos": Point(),
"mouseHeld": False,
"lastVelocity": Vector()
}
mouseVelocity = Vector()
mouseBall = Ball()
mouseBall.moveable = False
tickerPoints = []
MAX_TICKER_POINTS = 100
TICKER_PERIOD = 0.02
timeSinceLastTicker = 0
ball = Ball()
ball.setPos(Point(WIDTH/2, HEIGHT/2))
string = String()
string.setConnections(mouseBall, ball)
string.active = False
while True:
DISPLAY.fill(WHITE)
deltaT = CLOCK.get_time()/1000
totalTime += deltaT
moveData["lastPos"] = Point(moveData["currentPos"])
if not moveData["lastScreenMousePos"] == Point(pygame.mouse.get_pos()):
moveData["currentPos"] = Point(worldPos(Point(pygame.mouse.get_pos())))
moveData["lastScreenMousePos"] = Point(pygame.mouse.get_pos())
heldKeys = pygame.key.get_pressed()
for e in pygame.event.get():
if e.type == pygame.QUIT:
pygame.quit()
elif e.type == pygame.KEYDOWN:
heldKeys = pygame.key.get_pressed()
if (heldKeys[pygame.K_RCTRL] or heldKeys[pygame.K_LCTRL]) and\
(heldKeys[pygame.K_w] or heldKeys[pygame.K_q]):
pygame.quit()
if (heldKeys[pygame.K_SPACE]):
mouseBallDist = moveData["currentPos"].distance(ball.pos)
if mouseBallDist > 0:
string.toggle()
string.length = mouseBallDist
elif e.type == pygame.MOUSEBUTTONDOWN:
if e.button == 1:
moveData["mouseHeld"] = True
elif e.type == pygame.MOUSEBUTTONUP:
if e.button == 1:
moveData["mouseHeld"] = False
keyboardMoveSpeed = 1
if heldKeys[pygame.K_a]:
moveData["currentPos"] = moveData["currentPos"] - Point(keyboardMoveSpeed*deltaT, 0)
elif heldKeys[pygame.K_d]:
moveData["currentPos"] = moveData["currentPos"] + Point(keyboardMoveSpeed*deltaT, 0)
if heldKeys[pygame.K_w]:
moveData["currentPos"] = moveData["currentPos"] + Point(0, keyboardMoveSpeed*deltaT)
elif heldKeys[pygame.K_s]:
moveData["currentPos"] = moveData["currentPos"] - Point(0, keyboardMoveSpeed*deltaT)
if deltaT > 0:
moveData["lastVelocity"] = Vector(mouseBall.velocity)
mouseVelocity = Vector(((moveData["currentPos"]-moveData["lastPos"])/deltaT).pos())
mouseAcceleration = (mouseVelocity - moveData["lastVelocity"])/deltaT
else:
mouseVelocity = Vector()
mouseAcceleration = Vector()
mouseBall.setPos(moveData["currentPos"])
mouseBall.setVelocity(mouseVelocity)
#gravity adjustment
if heldKeys[pygame.K_i]:
GRAVITY = min(30.0,GRAVITY+0.1)
elif heldKeys[pygame.K_k]:
GRAVITY = max(0.0,GRAVITY-0.1)
#ball radius
if heldKeys[pygame.K_o]:
ball.radius = min(4.0,ball.radius+0.01)
elif heldKeys[pygame.K_l]:
ball.radius = max(0.1,ball.radius-0.01)
#string length
if heldKeys[pygame.K_u]:
string.length = min(8.0,string.length+0.01)
elif heldKeys[pygame.K_j]:
string.length = max(0.01,string.length-0.01)
#reset all
if heldKeys[pygame.K_r]:
GRAVITY = 9.81
ball.radius = 0.1
string.length = 2.0
if ball.bottom <= 0:
if ball.velocity.y < 0:
ball.accelerate(Vector((0, -ball.velocity.y-ball.velocity.y*ball.cor)))
else:
ball.accelerate(Vector((0, -GRAVITY))*deltaT)
#print(ball.velocity)
if ball.left <= 0:
if ball.velocity.x < 0:
ball.accelerate(Vector((-ball.velocity.x-ball.velocity.x*ball.cor, 0)))
if ball.right >= WIDTH:
if ball.velocity.x > 0:
ball.accelerate(Vector((-ball.velocity.x-ball.velocity.x*ball.cor, 0)))
string.applyTension(deltaT)
if moveData["mouseHeld"]:
ball.setPos(moveData["currentPos"])
ball.setVelocity(mouseBall.velocity)
ball.setInEquilibrium()
else:
ball.move(deltaT)
string.correctPositions()
# === DRAW
# draw person
DISPLAY.blit(personImage, (-(1/3)*personImage.get_rect().width, SCREEN_HEIGHT-personImage.get_rect().height))
# draw ticker tape
if not moveData["mouseHeld"]:
timeSinceLastTicker += deltaT
if timeSinceLastTicker >= TICKER_PERIOD:
tickerPoints.append(Point(ball.pos))
if len(tickerPoints) > MAX_TICKER_POINTS:
del tickerPoints[0]
timeSinceLastTicker = 0
else:
tickerPoints = []
for p in tickerPoints:
pygame.draw.circle(DISPLAY, BLUE, drawPos(p), 2, 2)
# draw mouse velocity vector
drawVector(mouseBall.velocity, moveData["currentPos"], 20, False, BLUE)
# velocity vector is scaled so it can be more easily comprehended
drawVector(ball.velocity, ball.pos, 10, False, GREEN, 1)
# draw ball
pygame.draw.circle(DISPLAY, RED, drawPos(ball.pos), int(ball.radius*SCALE), 1)
if string.active:
pygame.draw.line(DISPLAY, GREEN, drawPos(ball.pos), drawPos(moveData["currentPos"]), 1)
font = pygame.font.SysFont("monospace", 15)
# render text
fps = font.render("{}fps".format(int(CLOCK.get_fps())), 1, BLACK)
DISPLAY.blit(fps, (10, 10))
ballVelLabel = font.render("Ball velocity: {:.2f}ms-1".format(ball.velocity.mag), 1, BLACK)
DISPLAY.blit(ballVelLabel, (10, 30))
mouseVelLabel = font.render("Mouse velocity: {:.2f}ms-1".format(mouseBall.velocity.mag), 1, BLACK)
DISPLAY.blit(mouseVelLabel, (10, 50))
gravityVelLabel = font.render("Gravity: {:.2f}ms-2".format(GRAVITY), 1, BLACK)
DISPLAY.blit(gravityVelLabel, (10, 70))
diameterVelLabel = font.render("Ball diameter: {:.2f}m".format(ball.radius*2), 1, BLACK)
DISPLAY.blit(diameterVelLabel, (10, 90))
stringVelLabel = font.render("String length: {:.2f}m".format(string.length), 1, BLACK)
DISPLAY.blit(stringVelLabel, (10, 110))
#control prompts
stringConnect = font.render("Connect string: SPACE", 1, BLACK)
DISPLAY.blit(stringConnect, (SCREEN_WIDTH-stringConnect.get_rect().width-10, 10))
stringControl = font.render("String length +/-: U/J", 1, BLACK)
DISPLAY.blit(stringControl, (SCREEN_WIDTH-stringConnect.get_rect().width-10, 30))
gravityControl = font.render("Gravity +/-: I/K", 1, BLACK)
DISPLAY.blit(gravityControl, (SCREEN_WIDTH-stringConnect.get_rect().width-10, 50))
diameterControl = font.render("Ball diameter +/-: O/L", 1, BLACK)
DISPLAY.blit(diameterControl, (SCREEN_WIDTH-stringConnect.get_rect().width-10, 70))
resetAllControl = font.render("Reset all: R", 1, BLACK)
DISPLAY.blit(resetAllControl, (SCREEN_WIDTH-stringConnect.get_rect().width-10, 90))
pygame.display.update()
CLOCK.tick(120)
