【发布时间】：2013-05-19 01:51:34
【问题描述】：
我正在学习 pygame 教程，目前我正在尝试弄清楚如何选择一个正在发射球的圆圈，其中一个球击中另一个球，进而将一个盒子击倒。当球击中盒子时，敲击盒子效果很好。但是，当我添加鼠标移动以便我可以再次选择球并将其放置在相同的位置以便可以再次击中它时，框会再次敲击。球只是向后滚动，没有发射第二个球来敲击盒子。这是前面的代码，一个球发射另一个球但没有鼠标移动，即不允许选择和拖动球。
import pygame
from pygame.locals import *
from pygame.color import *
import pymunk as pm
from pymunk import Vec2d
import sys
from random import randint
def to_pygame(p):
"""Small hack to convert pymunk to pygame coordinates"""
return int(p[0]), int(-p[1]+600)
def draw_ball(screen, ball, colour):
r = ball.radius
rot = ball.body.rotation_vector
p = to_pygame(ball.body.position)
p2 = Vec2d(rot.x, -rot.y) * r * 0.9
pygame.draw.line(screen, THECOLORS["red"], p, p+p2)
pygame.draw.circle(screen, colour, p, int(r), 3)
def add_ball(space, x=0, y=130):
mass = 1.3
radius = 20
inertia = pm.moment_for_circle(mass, 0, radius, (0,0))
body = pm.Body(mass, inertia)
body.position = (x,y)
shape = pm.Circle(body, radius, (0,0))
shape.friction = 10.0
shape.elasticity = 1.0
space.add(body, shape)
return shape
def add_box(space, size, pos, mass=0.3):
points = [(-size, -size), (-size, size), (size,size), (size, -size)]
moment = pm.moment_for_poly(int(mass), points, (0,0))
body = pm.Body(mass, moment)
body.position = pos
shape = pm.Poly(body, points, (0,0))
shape.friction = 1
space.add(body,shape)
return shape
def draw_box(screen, box):
ps = box.get_points()
ps.append(ps[0])
newps = [to_pygame(x) for x in ps]
pygame.draw.polygon(screen, THECOLORS["blue"], newps, 3)
def main():
pygame.init()
screen = pygame.display.set_mode((600, 600))
pygame.display.set_caption("Impulsive balls")
clock = pygame.time.Clock()
balls = []
space = pm.Space()
space.gravity = (0.0, -300.0)
# ground
body = pm.Body()
shape = pm.Segment(body, (0,100), (450,100), .0)
shape.friction = 6.0
space.add(shape)
# hidden ramp
body = pm.Body()
slope = pm.Segment(body, (0,100), (180,150), .0)
space.add(slope)
balls.append(add_ball(space, 10, 130))
balls.append(add_ball(space, 100, 150))
#joint = pm.PinJoint(balls[0].body, balls[1].body)
#joint.distance = 90
mass = 1.0
size = 20
box = add_box(space, size, (400,100+size), mass)
count = 0
while 1:
space.step(1/30.0)
clock.tick(30)
for event in pygame.event.get():
if event.type == QUIT:
pygame.quit()
sys.exit(0)
elif event.type == KEYDOWN:
if event.key == K_ESCAPE:
pygame.quit()
sys.exit(0)
if count == 10:
pm.Body.apply_impulse(balls[0].body, (450,0))
screen.fill(THECOLORS["white"])
pygame.draw.line(screen, THECOLORS["red"], to_pygame((0,100)), to_pygame((450,100)), 3)
pygame.draw.line(screen, THECOLORS["red"], to_pygame((0,100)), to_pygame((180,150)), 3)
draw_box(screen, box)
for ball in balls:
draw_ball(screen, ball, THECOLORS["green"])
pygame.display.flip()
count += 1
if __name__ == '__main__':
main()
这是我添加鼠标移动代码的第二个版本
import pygame
from pygame.locals import *
from pygame.color import *
import pymunk as pm
from pymunk import Vec2d
import sys
from random import randint
def to_pygame(p):
"""Small hack to convert pymunk to pygame coordinates"""
return int(p[0]), int(-p[1]+600)
def from_pygame(p):
return to_pygame(p)
def draw_ball(screen, ball, colour):
r = ball.radius
rot = ball.body.rotation_vector
p = to_pygame(ball.body.position)
p2 = Vec2d(rot.x, -rot.y) * r * 0.9
pygame.draw.line(screen, THECOLORS["blue"], p, p+p2)
pygame.draw.circle(screen, colour, p, int(r), 3)
def add_ball(space, x=0, y=130):
mass = 1.3 #1.5
radius = 20
inertia = pm.moment_for_circle(mass, 0, radius, (0,0))
body = pm.Body(mass, inertia)
body.position = (x,y)
shape = pm.Circle(body, radius, (0,0))
shape.friction = 10.0
shape.elasticity = 1.0
space.add(body, shape)
return shape
def add_box(space, size, pos, mass=0.3):
points = [(-size, -size), (-size, size), (size,size), (size, -size)]
moment = pm.moment_for_poly(int(mass), points, (0,0))
body = pm.Body(mass, moment)
body.position = pos
shape = pm.Poly(body, points, (0,0))
shape.friction = 1
space.add(body,shape)
return shape
def draw_box(screen, box):
ps = box.get_points()
ps.append(ps[0])
newps = [to_pygame(x) for x in ps]
pygame.draw.polygon(screen, THECOLORS["blue"], newps, 3)
def main():
pygame.init()
screen = pygame.display.set_mode((600, 600))
pygame.display.set_caption("Impulsive balls")
clock = pygame.time.Clock()
body = []
selected = None
balls = []
space = pm.Space()
space.gravity = (0.0, -300.0)
# ground
body = pm.Body()
shape = pm.Segment(body, (0,100), (450,100), .0)
shape.friction = 6.0
space.add(shape)
# hidden ramp
body = pm.Body()
slope = pm.Segment(body, (0,100), (180,150), .0)
space.add(slope)
balls.append(add_ball(space, 10, 130))
balls.append(add_ball(space, 100, 150))
#joint = pm.PinJoint(balls[0].body, balls[1].body)
#joint.distance = 90
mass = 1.0
size = 20
box = add_box(space, size, (400,100+size), mass)
count = 0
while 1:
space.step(1/30.0)
clock.tick(30)
for event in pygame.event.get():
if event.type == QUIT:
pygame.quit()
sys.exit(0)
elif event.type == KEYDOWN:
if event.key == K_ESCAPE:
pygame.quit()
sys.exit(0)
if count == 10:
pm.Body.apply_impulse(balls[0].body, (450,0))
if event.key == K_p:
balls[0].body.apply_impulse((450,0))
if event.key == K_s:
balls[0].body.apply_impulse((-450,0))
elif event.type == MOUSEBUTTONDOWN:
p = from_pygame(Vec2d(event.pos))
selected = space.point_query_first(p)
elif event.type == MOUSEBUTTONUP:
if selected != None:
selected = None
elif event.type == MOUSEMOTION:
if selected != None:
selected.body.position = from_pygame(event.pos)
screen.fill(THECOLORS["white"])
pygame.draw.line(screen, THECOLORS["red"], to_pygame((0,100)), to_pygame((450,100)), 3)
pygame.draw.line(screen, THECOLORS["red"], to_pygame((0,100)), to_pygame((180,150)), 3)
draw_box(screen, box)
for ball in balls:
draw_ball(screen, ball, THECOLORS["green"])
pygame.display.flip()
count += 1
if __name__ == '__main__':
main()
另外，我怎样才能让球在同一位置，以便我可以拖动它并推动另一个球来敲击盒子而不是让球滚回，这样我以后可以再次选择发射的球并放置它在球旁边不回滚
【问题讨论】：
标签： python pygame game-physics