Pygame鼠标移动失败

Question

我正在研究pygame教程，目前我正在试图弄清楚如何选择一个圆球，这是一个球击中另一个球，而球又击倒了一个球。当球击中盒子时，盒子敲击工作正常。但是，当我添加鼠标移动时，我可以再次选择球并将其放置在相同的位置，以便再次击中它以便盒子再次敲击。球只是向后滚动而没有射击第二个球来敲击盒子。这是以前的代码，它可以用一个球击中另一个球而不用鼠标移动，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，我怎样才能将球放在同一个位置，以便我可以拖动它并推动另一个球来敲击球而不是让球回滚，所以稍后我可以再次选择击球并放置它在没有回滚的球旁边

Answer 1

对于你的第一个问题，球没有在第二个文件中射击。问题是您已将该代码放入事件块中，该事件块仅在触发外部事件时发生（例如按下某个键）。要修复它，需要将该块移出for循环，如下所示：

...

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 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)

    if count == 10:
        pm.Body.apply_impulse(balls[0].body, (450,0))

...

为防止球移动，我建议将球放在平地上。我对main进行了以下更改以显示我的意思。请注意，我禁用了球的射击，以便您可以看到球保持在原位。我还建议您在屏幕上放置一些看不见的墙壁，以防止所有物体卡在框架内。

...

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, (20,100), (180,150), .0)
    space.add(slope)
    body = pm.Body()
    slopetop = pm.Segment(body, (180,150), (190,150), .0)
    space.add(slopetop)

    balls.append(add_ball(space, 10, 130))
    balls.append(add_ball(space, 185, 170))
    #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 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)

        if count == 10 and 0:
            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((20,100)), to_pygame((180,150)), 3)
        pygame.draw.line(screen, THECOLORS["red"], to_pygame((180,150)), to_pygame((190,150)), 3)

        draw_box(screen, box)
        for ball in balls:
            draw_ball(screen, ball, THECOLORS["green"])

        pygame.display.flip()
        count += 1
...