Vector 为什么我的球向量在重新输入后仍保留其分量?
我正在用Pygame编写一个乒乓球游戏,这是到目前为止我的Ball类的代码:Vector 为什么我的球向量在重新输入后仍保留其分量?,vector,pygame,pong,Vector,Pygame,Pong,我正在用Pygame编写一个乒乓球游戏,这是到目前为止我的Ball类的代码: class Ball(pygame.sprite.Sprite): def __init__(self, game, vector=Vec2D.Vec2D()): super(Ball, self).__init__() self.image = pygame.Surface((BALL_RADIUS*2, BALL_RADIUS*2)) self.rect
class Ball(pygame.sprite.Sprite):
def __init__(self, game, vector=Vec2D.Vec2D()):
super(Ball, self).__init__()
self.image = pygame.Surface((BALL_RADIUS*2, BALL_RADIUS*2))
self.rect = self.image.get_rect()
self.__draw_ball()
screen = pygame.display.get_surface()
self.area = screen.get_rect().inflate(-GAP*2, 0)
self.vector = vector
self.game = game
self.reinit()
def __draw_ball(self):
self.image.fill(BLACK)
self.image.set_colorkey(BLACK, RLEACCEL)
pygame.draw.circle(self.image, WHITE, (self.rect.centerx, self.rect.centery), BALL_RADIUS)
def reinit(self):
self.rect.centerx = self.area.centerx
self.rect.centery = self.area.centery
self.vector = Vec2D.Vec2D.from_magn_and_angle(BALL_SPEED, 0)
def update(self):
self.rect = self.calcnewpos()
self.handle_collision()
def calcnewpos(self):
(dx, dy) = self.vector.get_xy()
return self.rect.move(dx, dy)
def handle_collision(self):
(dx, dy) = self.vector.get_xy()
if not self.area.contains(self.rect):
if self.__hit_topbottom():
dy = -dy
elif self.__hit_leftright():
self.game.increase_score()
self.reinit()
else:
for paddle in self.hit_paddle(dx):
if dx < 0: self.rect.left = GAP + PADDLE_WIDTH
elif dx > 0: self.rect.right = SCREEN_WIDTH - (GAP + PADDLE_WIDTH)
dx = -dx
dy = paddle.hitpos / 4
paddle.collided = True
self.vector = Vec2D.Vec2D(dx, dy)
def _hit_topbottom(self):
return self.rect.top < 0 or self.rect.bottom > SCREEN_HEIGHT
def _hit_leftright(self):
return self.rect.left < self.area.left or self.rect.right > self.area.right
def hit_paddle(self, dx):
if dx < 0: paddle = self.game.paddles['left']
elif dx > 0: paddle = self.game.paddles['right']
if self.rect.colliderect(paddle.rect): return [paddle]
else: return []
但是,不知何故,球仍然保持着它被调用之前的向量。因此,当球以类似(-5.0-2.0)的向量通过左侧时,它会在reinit调用中快速变化,然后变回(-5.0,-2.0)。有人能告诉我为什么会发生这种情况吗?问题出在您的
处理冲突的方法中
短篇小说:
函数要做的第一件事是将dx和dy设置为当前向量。然后它调用reinit()
。然后,它将它们设置回函数末尾的第一个
要修复:
改变
def handle_冲突(自):
(dx,dy)=self.vector.get_xy()#可能是每次都将球设置为相同的向量。从我在发布的代码中看到的情况来看,您根本不会更改或随机选择向量。@每次向量碰到墙或手柄碰撞方法中的某个挡板时,阴影都会更改。但当得分时,我希望reinit始终将向量设置为相同的向量Vec2D.Vec2D。从_magn_和_角度(球的速度,0)
@Shade,向量实际上会发生变化!它只是很快地恢复到以前的状态,然后可能还有什么东西在处理向量,在向量重置后“完成”。这似乎不太可能,但是。。。还有一些突出的地方,dy=palle.hitpos/4
可能总是被截断为一个整数,而dx将永远(从我所看到的)等于dx或-dx。好的,我看到了。我会发布一个答案后,我键入它outSorry,它的工作!但我还是不明白。你能进一步解释一下为什么会这样吗?我现在明白了!谢谢,夏德。
def reinit(self):
self.rect.centerx = self.area.centerx
self.rect.centery = self.area.centery
self.vector = Vec2D.Vec2D.from_magn_and_angle(BALL_SPEED, 0)
def handle_collision(self):
(dx, dy) = self.vector.get_xy() # <-- It first sets (dx, dy) to the old vector
if not self.area.contains(self.rect):
if self.__hit_topbottom():
...
elif self.__hit_leftright():
... # <-- here is where the reinit gets called, which changes the vector to new values.
else:
for paddle in self.hit_paddle(dx):
...
self.vector = Vec2D.Vec2D(dx, dy) # <-- Then the vector gets changed again, to the OLD vector saved above in (dx, dy)
def handle_collision(self):
(dx, dy) = self.vector.get_xy()
if not self.area.contains(self.rect):
if self.__hit_topbottom():
...
elif self.__hit_leftright():
...
return # <-- With the return here, the parsing never gets to change it back
else:
for paddle in self.hit_paddle(dx):
...
self.vector = Vec2D.Vec2D(dx, dy)