Question

我和我的一个朋友刚刚开始学习在repl.it上使用pygame进行编程，对于我们的第一个“真实”项目，我们希望建立一个像“点击鼠标”这样的古老学校。

但是，我们在角色移动方面存在问题，如果我们在屏幕上单击某个位置，该角色只是“传送”在那里，但我们希望它看起来尽可能平滑。

因此，基本上，我们希望摆脱字符的“传送”，而是从字符当前位置到鼠标位置进行逐帧平滑过渡。

我们已经尝试减慢while循环，以便每次执行while循环时都可以投影字符，但这只会使整个站点崩溃，我们还尝试在repl.it之外进行操作，以防万一。该网站存在问题，但该网站也无法正常工作。

#PMC = Character
#mpos = the mouse position 
#mstate= the state of the mouse buttons (0 if nothing is pressed, 1 if a mouse 
#button is pressed) 
#charspeed = the speed at which the character moves (=1px)
  ```
#---PMC movement when mouse click-----------------------
    #---x,y = mpos   x2,y2 = characterpos
    if mstate == (1,0,0):
      #print('x: ', x, ' y: ', y, '   x2: ', x2, ' y2: ', y2) #debugging_positions

      
      while x2 != x:
        if x2>x:
          x2-=charspeed
          screen.blit(pmc, (x2-46, y2-184))
        if x2<x:
          x2+=charspeed
          screen.blit(pmc, (x2-46, y2-184))
          
      while y2 != y:
        if y2>y:
          y2 -= charspeed
          screen.blit(pmc, (x2-46, y2-184))
        if y2<y:
          y2 += charspeed
          screen.blit(pmc, (x2-46, y2-184))

Answer 1

您有一个游戏循环，请使用它。只需在每个帧中将角色移动一定位置即可。例如，每帧将字符移动step：

step = 1

if x2 + step <= x:
    x2 += step
elif x2 - step >= x:
    x2 -= step
else:
    x2 = x

if y2 + step <= y:
    y2 += step
elif y2 - step >= y:
    y2 -= step
else:
    y2 = y

对于更复杂的解决方案，您必须计算Euclidean distance形式的指向目标的点。使用pygame.math.Vector2进行计算。

计算从动轴与子图形之间的距离以及单位方向向量从（follower_x，follower_y）到（mainsprite_x，mainsprite_y）。 Unit Vector可以通过将方向矢量除以距离或将方向矢量归一化（normalize()）来计算：

target_vector = Vector2(mainsprite_x, mainsprite_y)
follower_vector = Vector2(follower_x, follower_y)

distance = follower_vector.distance_to(target_vector)
direction_vector = target_vector - follower_vector
if distance > 0:
    direction_vector /= distance

现在，您可以定义精确的step_distance并移动到精灵的跟随者int方向：

if distance > 0:
    new_follower_vector = follower_vector + direction_vector * step_distance.

定义maximum_distance和minimum_distance。最小步距为：

min_step = max(0, distance - maximum_distance)

最大步距为

max_step = distance - minimum_distance

将它们放在一起：

minimum_distance    = 0
maximum_distance    = 10000
target_vector       = Vector2(mainsprite_x, mainsprite_y)
follower_vector     = Vector2(follower_x, follower_y)
new_follower_vector = Vector2(follower_x, follower_y)

distance = follower_vector.distance_to(target_vector)
if distance > minimum_distance:
    direction_vector    = (target_vector - follower_vector) / distance
    min_step            = max(0, distance - maximum_distance)
    max_step            = distance - minimum_distance
    step_distance       = min_step + (max_step - min_step) * LERP_FACTOR
    new_follower_vector = follower_vector + direction_vector * step_distance

最小示例： repl.it/@Rabbid76/PyGame-FollowMouseSmoothly

import pygame

LERP_FACTOR      = 0.05
minimum_distance = 25
maximum_distance = 100

def FollowMe(pops, fpos):
    target_vector       = pygame.math.Vector2(*pops)
    follower_vector     = pygame.math.Vector2(*fpos)
    new_follower_vector = pygame.math.Vector2(*fpos)

    distance = follower_vector.distance_to(target_vector)
    if distance > minimum_distance:
        direction_vector    = (target_vector - follower_vector) / distance
        min_step            = max(0, distance - maximum_distance)
        max_step            = distance - minimum_distance
        step_distance       = min_step + (max_step - min_step) * LERP_FACTOR
        new_follower_vector = follower_vector + direction_vector * step_distance

    return (new_follower_vector.x, new_follower_vector.y) 

pygame.init()
window = pygame.display.set_mode((500, 500))
clock = pygame.time.Clock()

follower = (100, 100)
run = True
while run:
    clock.tick(60)
    for event in pygame.event.get():
        if event.type == pygame.QUIT:
            run = False

    player   = pygame.mouse.get_pos()
    follower = FollowMe(player, follower)

    window.fill(0)  
    pygame.draw.circle(window, (0, 0, 255), player, 10)
    pygame.draw.circle(window, (255, 0, 0), (round(follower[0]), round(follower[1])), 10)
    pygame.display.flip()

Answer 2

我不建议您使用repl.it，因为它往往运行非常缓慢。

另外，您的代码应更像这样：

    while True:
        screen.fill((0,0,0))

        stuff happens

        if x2>x:
            x2-=charspeed
        elif x2<x:
            x2+=charspeed
        elif y2>y:
            y2 -= charspeed
        elif y2<y:
            y2 += charspeed
        screen.blit(pmc, (x2-46, y2-184))
        pygame.display.flip()

直到显示器完全移动到（x，y）之前，您都不会更新显示器

如何在Pygame中使动作平稳

2 个答案: