蛇游戏 - 边界

Question

我开始制作这个蛇游戏，我遇到了一场斗争。我希望当蛇到达一侧的末端时，它会从另一侧来，如果它到达左侧的末端，它将从右侧出来，如果它到达上端，它将从底部出来。如果有人能告诉我如何做到这一点，我将非常感激。

import pygame

BLACK = (0, 0, 0)
WHITE = (255, 255, 255)

segment_width = 15
segment_height = 15
segment_margin = 3

x_change = segment_width + segment_margin
y_change = 0


class Segment(pygame.sprite.Sprite):

    def __init__(self, x, y):
        super().__init__()

       self.image = pygame.Surface([segment_width, segment_height])
       self.image.fill(WHITE)

       self.rect = self.image.get_rect()
       self.rect.x = x
       self.rect.y = y

pygame.init()


screen = pygame.display.set_mode([1200, 800])


pygame.display.set_caption('Snakes')

allspriteslist = pygame.sprite.Group()

snake_segments = []
for i in range(3):
    x = 250 - (segment_width + segment_margin) * i
    y = 30
    segment = Segment(x, y)
    snake_segments.append(segment)
    allspriteslist.add(segment)


clock = pygame.time.Clock()
done = False

while not done:

    for event in pygame.event.get():
        if event.type == pygame.QUIT:
            done = True

        if event.type == pygame.KEYDOWN:
            if event.key == pygame.K_LEFT:
                x_change = (segment_width + segment_margin) * -1
                y_change = 0
            if event.key == pygame.K_RIGHT:
                x_change = (segment_width + segment_margin)
                y_change = 0
            if event.key == pygame.K_UP:
                x_change = 0
                y_change = (segment_height + segment_margin) * -1
            if event.key == pygame.K_DOWN:
                x_change = 0
                y_change = (segment_height + segment_margin)


    old_segment = snake_segments.pop()
    allspriteslist.remove(old_segment)

    x = snake_segments[0].rect.x + x_change
    y = snake_segments[0].rect.y + y_change
    segment = Segment(x, y)

    snake_segments.insert(0, segment)
    allspriteslist.add(segment)

    screen.fill(BLACK)

    allspriteslist.draw(screen)

    pygame.display.flip()

    clock.tick(5)

pygame.quit()

Answer 1

您可以使用if检查位置并移至另一侧

x = snake_segments[0].rect.x + x_change
y = snake_segments[0].rect.y + y_change

if x < screen_rect.left:
    x += screen_rect.width
elif x + segment_width + segment_margin > screen_rect.right:
    x -= screen_rect.width

if y < screen_rect.top:
    y += screen_rect.height
elif y + segment_height + segment_margin > screen_rect.bottom:
    y -= screen_rect.height

segment = Segment(x, y)

但问题是片段没有理想地填充屏幕 - 有时你应该在一侧显示部分片段而在另一侧显示片段。您必须将方法draw()添加到Segment，这将检查您是否必须在两侧绘制线段并绘制两个线段 - 首先在一侧，第二个在另一侧。

    def draw(self, screen):

        # draw oryginal segment

        screen_rect = screen.get_rect()
        screen.blit(self.image, self.rect)

        # draw second segment on other side

        # left - right
        if self.rect.left < screen_rect.left:
            temp_rect = self.rect.copy()
            temp_rect.x += screen_rect.width
            screen.blit(self.image, temp_rect)
        elif self.rect.right > screen_rect.right:
            temp_rect = self.rect.copy()
            temp_rect.x -= screen_rect.width
            screen.blit(self.image, temp_rect)

        # top - bottom
        if self.rect.top < screen_rect.top:
            temp_rect = self.rect.copy()
            temp_rect.y += screen_rect.height
            screen.blit(self.image, temp_rect)
        elif self.rect.bottom > screen_rect.bottom:
            temp_rect = self.rect.copy()
            temp_rect.y -= screen_rect.height
            screen.blit(self.image, temp_rect)

但这意味着您必须手动执行此功能，因为group.draw()直接运行screen.blit(self.image, self.rect)

for x in allspriteslist:
    x.draw(screen)

完整代码

import pygame

BLACK = (0, 0, 0)
WHITE = (255, 255, 255)

segment_width = 15
segment_height = 15
segment_margin = 3

x_change = segment_width + segment_margin
y_change = 0


class Segment(pygame.sprite.Sprite):

    def __init__(self, x, y):
       super().__init__()

       self.image = pygame.Surface([segment_width, segment_height])
       self.image.fill(WHITE)

       self.rect = self.image.get_rect()
       self.rect.x = x
       self.rect.y = y

    def draw(self, screen):
        screen_rect = screen.get_rect()
        screen.blit(self.image, self.rect)

        if self.rect.left < screen_rect.left:
            temp_rect = self.rect.copy()
            temp_rect.x += screen_rect.width
            screen.blit(self.image, temp_rect)
        elif self.rect.right > screen_rect.right:
            temp_rect = self.rect.copy()
            temp_rect.x -= screen_rect.width
            screen.blit(self.image, temp_rect)

        if self.rect.top < screen_rect.top:
            temp_rect = self.rect.copy()
            temp_rect.y += screen_rect.height
            screen.blit(self.image, temp_rect)
        elif self.rect.bottom > screen_rect.bottom:
            temp_rect = self.rect.copy()
            temp_rect.y -= screen_rect.height
            screen.blit(self.image, temp_rect)


pygame.init()


screen = pygame.display.set_mode((1200, 800))
screen_rect = screen.get_rect()

pygame.display.set_caption('Snakes')

allspriteslist = pygame.sprite.Group()

snake_segments = []
for i in range(3):
    x = 250 - (segment_width + segment_margin) * i
    y = 30
    segment = Segment(x, y)
    snake_segments.append(segment)
    allspriteslist.add(segment)


clock = pygame.time.Clock()
done = False

while not done:

    for event in pygame.event.get():
        if event.type == pygame.QUIT:
            done = True

        if event.type == pygame.KEYDOWN:
            if event.key == pygame.K_LEFT:
                x_change = (segment_width + segment_margin) * -1
                y_change = 0
            if event.key == pygame.K_RIGHT:
                x_change = (segment_width + segment_margin)
                y_change = 0
            if event.key == pygame.K_UP:
                x_change = 0
                y_change = (segment_height + segment_margin) * -1
            if event.key == pygame.K_DOWN:
                x_change = 0
                y_change = (segment_height + segment_margin)


    old_segment = snake_segments.pop()
    allspriteslist.remove(old_segment)

    x = snake_segments[0].rect.x + x_change
    y = snake_segments[0].rect.y + y_change

    if x < screen_rect.left:
        x += screen_rect.width
    elif x + segment_width + segment_margin > screen_rect.right:
        x -= screen_rect.width

    if y < screen_rect.top:
        y += screen_rect.height
    elif y + segment_height + segment_margin > screen_rect.bottom:
        y -= screen_rect.height

    segment = Segment(x, y)

    snake_segments.insert(0, segment)
    allspriteslist.add(segment)

    screen.fill(BLACK)

    #allspriteslist.draw(screen)

    for x in allspriteslist:
        x.draw(screen)

    pygame.display.flip()

    clock.tick(5)

pygame.quit()