Python 如何"；作物“；Pygame中的旋转图像

问题：

def updateTime(screen, hudtimecircle, time):
    center = (200, 200)                                        # The center of where the rotated image will be drawn
    amount = time                                              # just a number 1-360

    newcircle = pygame.transform.rotate(hudtimecircle, amount) # The rotated version of the un-rotated "hudtimecircle" image
    newrect = newcircle.get_rect()                             # The rect of the rotated image
    newrect.center = center                                    # Setting the middle of the rotated rect to the point I want to be the center

    crop = (0, 0, 120, 60)                                     # An area that I want to be left when I "Crop", This is the part that needs fixing
    cropped = newcircle.subsurface(crop)                       # The cropped part of the rotated image, I want/need this to only give the top half of the image.
    screen.blit(cropped, newrect.topleft)                      # Drawing the rotated image with it's middle point where the variable "center" says.

我试图在Pygame中绘制旋转图像，但我只希望显示图像的上半部分。我已设法旋转图像，使其正确居中，但我无法将其裁剪为仅显示上半部分

我认为这是由于矩形正在旋转，当我使用

surface.subsurface（）

将其裁剪为某个矩形时，裁剪的部分会产生“反弹”效果，因为矩形会随着旋转角度的不同而越来越大越来越小

代码：

def updateTime(screen, hudtimecircle, time):
    center = (200, 200)                                        # The center of where the rotated image will be drawn
    amount = time                                              # just a number 1-360

    newcircle = pygame.transform.rotate(hudtimecircle, amount) # The rotated version of the un-rotated "hudtimecircle" image
    newrect = newcircle.get_rect()                             # The rect of the rotated image
    newrect.center = center                                    # Setting the middle of the rotated rect to the point I want to be the center

    crop = (0, 0, 120, 60)                                     # An area that I want to be left when I "Crop", This is the part that needs fixing
    cropped = newcircle.subsurface(crop)                       # The cropped part of the rotated image, I want/need this to only give the top half of the image.
    screen.blit(cropped, newrect.topleft)                      # Drawing the rotated image with it's middle point where the variable "center" says.

我尝试过相对于旋转的矩形进行裁剪，如下所示：

crop = (newrect.topleft[0], newrect.topleft[1], newrect.midright[0], newrect.midright[1])

但是，这不起作用，并返回

ValueError:subground rectangle outside surface area

，因为每个或一些点都在图像区域之外

其他信息：

def updateTime(screen, hudtimecircle, time):
    center = (200, 200)                                        # The center of where the rotated image will be drawn
    amount = time                                              # just a number 1-360

    newcircle = pygame.transform.rotate(hudtimecircle, amount) # The rotated version of the un-rotated "hudtimecircle" image
    newrect = newcircle.get_rect()                             # The rect of the rotated image
    newrect.center = center                                    # Setting the middle of the rotated rect to the point I want to be the center

    crop = (0, 0, 120, 60)                                     # An area that I want to be left when I "Crop", This is the part that needs fixing
    cropped = newcircle.subsurface(crop)                       # The cropped part of the rotated image, I want/need this to only give the top half of the image.
    screen.blit(cropped, newrect.topleft)                      # Drawing the rotated image with it's middle point where the variable "center" says.

图像

hudtimecircle

是120px*120px，是一个圆的图像，有一个透明的背景，我只想在旋转后绘制圆的顶部60px

amount

和

time

只是从1到360的数字，我有这一行，因为我计划稍后处理amount

我不能只是在图像的下半部分的顶部点击另一个图像来“裁剪”它，因为在下面有许多不同的东西需要放置这个图像

我已经看过了：

def updateTime(screen, hudtimecircle, time):
    center = (200, 200)                                        # The center of where the rotated image will be drawn
    amount = time                                              # just a number 1-360

    newcircle = pygame.transform.rotate(hudtimecircle, amount) # The rotated version of the un-rotated "hudtimecircle" image
    newrect = newcircle.get_rect()                             # The rect of the rotated image
    newrect.center = center                                    # Setting the middle of the rotated rect to the point I want to be the center

    crop = (0, 0, 120, 60)                                     # An area that I want to be left when I "Crop", This is the part that needs fixing
    cropped = newcircle.subsurface(crop)                       # The cropped part of the rotated image, I want/need this to only give the top half of the image.
    screen.blit(cropped, newrect.topleft)                      # Drawing the rotated image with it's middle point where the variable "center" says.

还有其他一些不太相关的问题

只是澄清一下，我的问题不是旋转图像，或者使旋转后的图像居中。问题是我只需要显示旋转的、居中的图像的上半部分

---

如果还需要其他信息，我很乐意提供。

您必须将crop变量放在括号中，因此：

您的代码：

crop = (0, 0, 120, 60)
cropped = newcircle.subsurface(crop)

右代码：

crop = (0, 0, 120, 60)
cropped = newcircle.subsurface((crop))

---

注意我，如果这样做有效。

这就是你想要达到的效果吗？每次旋转后都必须计算新的裁剪位置，因为旋转图像的大小一直在变化。在左上角，您可以看到父图像/曲面如何更改

import sys
import pygame as pg


def main():
    pg.init()
    screen = pg.display.set_mode((320, 240))
    clock = pg.time.Clock()
    done = False
    bg_color = pg.Color(50, 80, 120)
    # Create the original image that we use for the rotation
    # to avoid visual degeneration.
    orig_img = pg.Surface((100, 100))
    orig_img.fill((20, 50, 130))
    pg.draw.circle(orig_img, pg.Color('springgreen2'), (30, 30), 30)
    pg.draw.circle(orig_img, pg.Color('lightgoldenrod3'), (60, 60), 30)
    pg.draw.rect(orig_img, pg.Color('black'), (48, 0, 4, 100))
    pg.draw.rect(orig_img, pg.Color('black'), (0, 48, 100, 4))
    rect = orig_img.get_rect(topleft=(30, 30))

    angle = 0

    while not done:
        for event in pg.event.get():
            if event.type == pg.QUIT:
                done = True

        angle += 1
        # Rotate the image.
        img = pg.transform.rotate(orig_img, angle)
        rect = img.get_rect(center=rect.center)
        # Calculate new crop position. Half of the new
        # width & height minus half of the original dimensions.
        x, y = rect.width/2 - 50, rect.height/2 - 50
        sub = img.subsurface((x, y, 100, 50))

        screen.fill(bg_color)

        screen.blit(img, rect)
        screen.blit(sub, (150, 150))

        pg.display.flip()
        clock.tick(30)


if __name__ == "__main__":
    main()
    pg.quit()
    sys.exit()

---

可悲的是，这并不能解决问题。您的代码和我的代码都会裁剪图像，但由于旋转，裁剪区域会根据旋转的角度发生变化。因此，如果图像上没有旋转，则裁剪可以正常工作并精确获得图像的上半部分，但任何旋转都会导致裁剪部分变大或变小。@Charlton Lane是否尝试设置裁剪曲面的矩形？此更改没有任何效果。你只要用多余的圆括号把作物包起来就行了！这正是我所需要的，我把它应用到我的图片上，效果非常好。