python - 向下循环鼠标按钮以绘制线条

Question

需要用mousebuttondown画线而不是点

当单击鼠标时程序绘制点，我假设需要另一个循环来在按住鼠标按钮的情况下绘制线条。

while keep_going:
    for event in pygame.event.get():
        if event.type == pygame.QUIT:
            keep_going = False
        if event.type == pygame.MOUSEBUTTONDOWN:
            spot = event.pos
            pygame.draw.circle(screen, GREEN, spot, radius)
            pygame.display.update()

我想在窗口中画线而不是点。

Answer 1

使用pygame.draw.lines , 用线连接点列表。

如果鼠标按钮被释放，则将当前鼠标位置附加到列表中:

if event.type == pygame.MOUSEBUTTONUP:
    points.append(event.pos)

绘制点列表，如果列表中有超过1个点:

if len(points) > 1:
    pygame.draw.lines(screen, (255, 255, 255), False, points, width)

从列表中的最后一个点到当前鼠标位置绘制一条“橡皮筋”:

if len(points):
    pygame.draw.line(screen, (255, 255, 255), points[-1], pygame.mouse.get_pos(), width)

看简单的例子:

run = True
width = 3
points = []
while run:

    for event in pygame.event.get():
        if event.type == pygame.QUIT:
            run = False

        if event.type == pygame.MOUSEBUTTONUP:
            points.append(event.pos)

    screen.fill(0)
    if len(points) > 1:
        pygame.draw.lines(screen, (255, 255, 255), False, points, width)
    if len(points):
        pygame.draw.line(screen, (255, 255, 255), points[-1], pygame.mouse.get_pos(), width)
    pygame.display.flip()