滑动的精灵

问题描述

我想让我的精灵像他在冰上一样滑行。因此，如果他在地面上，他可以正常行走，但当他接触到冰时，他会滑动，直到有东西阻止他。 有人知道怎么才能做到这一点吗？ 谢谢

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解决方案

操作摩擦系数，如"Sprite Movement Towards a Target"示例(修改如下)：

class Sprite(pygame.sprite.Sprite):
    ICE = 0.01
    LAND = 1.

    def __init__(self):
        # ...
        self.normal_friction = .95 # friction while accelerating
        self.slowing_friction = .8 # friction while slowing down

    def update(self):
        # ...
        if self.dir: # if there is a direction to move

            if self.in_ice_region():
                surface_coefficient = Sprite.ICE
            else:
                surface_coefficient = Sprite.LAND

            if self.distance_check(self.dist): # if we need to slow down
                self.speedX += (self.dir[0] * (self.speed / 2)) # reduced speed
                self.speedY += (self.dir[1] * (self.speed / 2))
                self.speedX *= surface_coefficient * self.slowing_friction # increased friction
                self.speedY *= surface_coefficient * self.slowing_friction

            else: # if we need to go normal speed
                self.speedX += (self.dir[0] * self.speed) # calculate speed from direction to move and speed constant
                self.speedY += (self.dir[1] * self.speed)
                self.speedX *= surface_coefficient * self.normal_friction # apply friction
                self.speedY *= surface_coefficient * self.normal_friction

            self.trueX += self.speedX # store true x decimal values
            self.trueY += self.speedY
            self.rect.center = (round(self.trueX),round(self.trueY)) # apply values to sprite.center