为什么 collide_widget 在这里不起作用？

Question

我想知道为什么我的“collide_with_hero”方法似乎不起作用？我的 Npcs 课程有问题吗？

我只是想检测小部件何时发生碰撞（英雄和树小部件），我删除了方法中的所有附加代码，现在我只是试图检测碰撞并打印如果真的话。当我运行游戏并将我的英雄角色带入树中时，什么也没有打印，什么也没有发生。

我在构建中调用 self.tree.collide_with_widget。关于我在这里做错了什么有什么建议吗？

from kivy.app import App
from kivy.uix.widget import Widget
from kivy.uix.image import Image
from kivy.core.window import Window
from kivy.uix.screenmanager import ScreenManager, Screen
from kivy.uix.label import Label
from kivy.uix.behaviors import ButtonBehavior
from kivy.core.audio import SoundLoader
from kivy.uix.relativelayout import RelativeLayout
from kivy.uix.gridlayout import GridLayout
from kivy.uix.screenmanager import FallOutTransition


gamelayout = RelativeLayout(size=(300, 300))
bglayout = RelativeLayout()

class Game(Screen):
    pass    

class Bg(Image):

    def __init__(self, **kwargs):
        super(Bg, self).__init__(**kwargs)
        self.allow_stretch = True
        self.size_hint = (None, None)
        self.size = (1440, 1440)

class Npcs(Image):
    def __init__(self, **kwargs):
        super(Npcs, self).__init__(**kwargs)

    def collide_with_hero(self, hero):
        if self.collide_widget(hero):
            print "you ran into a tree"

            #dir1 = self.hero.x - self.x
            #if self.x < self.hero.x:
            #    self.hero.x = self.x + dir1


class MoveableImage(Image):

    def __init__(self, **kwargs):
        super(MoveableImage, self).__init__(**kwargs)
        self._keyboard = Window.request_keyboard(None, self)
        if not self._keyboard:
            return
        self._keyboard.bind(on_key_down=self.on_keyboard_down)
        self._keyboard.bind(on_key_up=self.on_keyboard_up)
        self.size_hint = (.11, .11)
        self.y = (Window.height/2.1)
        self.app = App.get_running_app()


    def on_keyboard_down(self, keyboard, keycode, text, modifiers):
        if keycode[1] == 'left':
            self.source = 'selectionscreen/left.zip'
            self.anim_delay=.20
            if self.x < (Window.width * .25):
                bglayout.x += 4
            else:
                self.x -= 6
        elif keycode[1] == 'right':
            self.source ='selectionscreen/right.zip'
            self.anim_delay=.20
            if self.x > (Window.width * .70):
                bglayout.x -= 4
            else:
                self.x += 6
        elif keycode[1] == 'down':
            self.source ='selectionscreen/right.zip'
            self.anim_delay=.20
            if self.y < (Window.height * .25):
                bglayout.y += 4
            else:
                self.y -= 6
        elif keycode[1] == 'up':
            self.source = 'selectionscreen/back.zip'
            self.anim_delay=.1
            if self.y > (Window.height * .70):
                bglayout.y -= 4
            else:
                self.y += 6
        else:
            return False
        return True

    def on_keyboard_up(self, keyboard, keycode):
        if keycode[1] == 'left':
            self.source = 'selectionscreen/left1.png'
        elif keycode[1] == 'right':
            self.source ='selectionscreen/right1.png'
        elif keycode[1] == 'down':
            self.source ='selectionscreen/right1.png'
        elif keycode[1] == 'up':
            self.source ='selectionscreen/back2.png'
        else:
            return False
        return True


class gameApp(App):
    def build(self):
        global sm
        sm = ScreenManager()
        game = Game(name='game')
        sm.add_widget(game)
        hero = MoveableImage(source='selectionscreen/right1.png', pos=(75, 40))
        self.tree = Npcs(source='selectionscreen/tree.zip', pos=(100, 200))
        self.tree.collide_with_hero(hero)
        self.background=Bg(source='selectionscreen/background9.png')

        #add widgets to bglayout
        bglayout.add_widget(self.background)
        bglayout.add_widget(self.tree)

        #add bglayout and moveable hero to gamelayout
        gamelayout.add_widget(bglayout)
        gamelayout.add_widget(hero)
        game.add_widget(gamelayout)

        return sm



if __name__ == '__main__':
    gameApp().run()

Answer 1

您需要一个主游戏循环来在某个时间间隔或按键事件后检查碰撞。您可以在此处查看 Pong 示例：http://kivy.org/docs/tutorials/pong.html 以了解如何实现这一目标。

更具体地说，从本节开始阅读：http://kivy.org/docs/tutorials/pong.html#adding-ball-animation。

    Clock.schedule_interval(game.update, 1.0/60.0)

它使用 Clock.schedule_interval 来调度一个名为“update”的主循环函数。

    def update(self, dt):
        self.ball.move()

        #bounce off top and bottom
        if (self.ball.y < 0) or (self.ball.top > self.height):
            self.ball.velocity_y *= -1

        #bounce off left and right
        if (self.ball.x < 0) or (self.ball.right > self.width):
            self.ball.velocity_x *= -1

您需要在这样的函数中编写碰撞检测代码。如果您的游戏涉及更复杂的物理模拟，那么您可以考虑使用像 http://box2d.org/ 这样的库。它会为你管理所有的碰撞和东西。

Answer 2

首先，您将self.tree 设为图像，但它没有collide_with_hero 方法。您需要使其成为您定义的新类 Npcs 的实例。

其次，你没有调用collide_with_hero 方法。您需要执行self.tree.collide_with_hero(hero) 才能实际调用它，包括将您的英雄作为参数传递给函数。