Question

我使用pygame绘制了这个网格：

如你所见，它从左上角开始。我这样画：

import pygame

# Color vars here

# Grid vars
WIDTH = 4
HEIGHT = 4
MARGIN = 1

# Initialize pygame
pygame.init()
WINDOW_SIZE = [820, 620]
screen = pygame.display.set_mode(WINDOW_SIZE)

# Loop until the user clicks the close button.
done = False

# Used to manage how fast the screen updates
clock = pygame.time.Clock()

# -------- Main Program Loop -----------
while not done:
    for event in pygame.event.get():
        if event.type == pygame.QUIT:
            done = True

    # Set the screen background
    screen.fill(BLACK)

    # Draw the grid
    for row in range(120):
        for column in range(160):
            # Set the color here

            # Draw rectangle
            pygame.draw.rect(screen, color, [(MARGIN + WIDTH) * column + MARGIN, (MARGIN + HEIGHT) * row + MARGIN, WIDTH, HEIGHT])

    # Limit to 60 frames per second
    clock.tick(60)

    # Update the screen
    pygame.display.flip()

# Prevent hang if idle
pygame.quit()

如何偏移网格，使其不会从左上角开始？我想把它向右和向下移动一下。任何帮助将不胜感激。

Answer 1

正如评论中提到的furas，有两种方法可以解决：

1。向元素

添加偏移量

如果要移动所有元素，例如x轴为16像素，y轴为32像素，则可以为每个元素添加偏移量。

offset_x, offset_y = 16, 32
for row in range(120):
    for column in range(160):
        pygame.draw.rect(screen, color, [(MARGIN + WIDTH) * column + MARGIN + offset_x, 
                                         (MARGIN + HEIGHT) * row + MARGIN + offset_y, 
                                          WIDTH, HEIGHT])

执行嵌套循环时要注意的一件事是可以在循环外移动的计算（Loop-invariant code motion）。例如，MARGIN + WIDHT，MARGIN + offset_x，MARGIN + HEIGHT和MARGIN + offset_y对于每次迭代都是相同的。如果我们计算循环之前的值，我们将每帧节省4 * 120 * 160 = 76,800次计算。

full_width, full_height = MARGIN + WIDHT, MARGIN + HEIGHT
offset_x, offset_y = 16 + MARGIN, 32 + MARGIN
for row in range(120):
    for column in range(160):
        pygame.draw.rect(screen, color, [full_width * column + offset_x, 
                                         full_height * row + offset_y, WIDTH, HEIGHT])

如果您想要的偏移量为6（包含边距的矩形的大小），假设6 * 5 = 30，则可以在索引5处启动循环并取消偏移值。 / p>

full_width, full_height = MARGIN + WIDHT, MARGIN + HEIGHT
for row in range(5, 125):
    for column in range(5, 165):
        pygame.draw.rect(screen, color, [full_width * column + MARGIN, 
                                         full_height * row + MARGIN, WIDTH, HEIGHT])

2。创建曲面

不是直接在屏幕上绘制（这是一个Surface对象），您可以创建一个与网格大小相同的新Surface对象，在其上绘制，然后以所需的偏移量对其进行blit。

rows, columns = 120, 160
grid_image = pygame.Surface((rows * (WIDTH + 2 * MARGIN), columns * (HEIGHT + 2 * MARGIN)))

在主循环内。

full_width, full_height = MARGIN + WIDHT, MARGIN + HEIGHT
for row in range(rows):
    for column in range(columns):
        pygame.draw.rect(grid_image, color, [full_width * column + MARGIN, 
                                             full_height * row + MARGIN, WIDTH, HEIGHT])


screen.blit(grid_image, (offset_x, offset_y))

Pygame偏移了由矩形构成的网格

1 个答案:

1。向元素

2。创建曲面