python - 如何制作透明的pygame.draw.circle

Question

这个问题已经有答案了:

Draw a transparent rectangles and polygons in pygame (4 个回答)

已关闭 2 年前。

如何制作pygame.draw.circle透明(添加 alpha 级别)，至于“表面”“set_alpha”？我找到了只能改变 pygame.draw.circle 颜色的解决方案调至较暗

Answer 1

您必须使用pygame.Surface 。创建具有每像素 alpha 图像格式的 Surface。例如:

radius = 100
circle = pygame.Surface((radius*2, radius*2), pygame.SRCALPHA)

并在其上画一个透明的圆圈。圆圈颜色的 Alpha channel 必须 < 255(例如 128):

pygame.draw.circle(circle, (255, 0, 0, 128), (radius, radius), radius)

blit() Surface 到窗口。例如:

window.blit(circle, (100, 100))

示例:

import pygame

pygame.init()
wndsize = (400, 400)
window = pygame.display.set_mode(wndsize)
clock = pygame.time.Clock()

run = True
while run:
    clock.tick(60)

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

    window.fill(0)
    pygame.draw.rect(window, (0, 0, 255), (0, 0, 200, 400))

    radius = 100
    circle = pygame.Surface((radius*2, radius*2), pygame.SRCALPHA)   
    pygame.draw.circle(circle, (255, 0, 0, 128), (radius, radius), radius)
    window.blit(circle, (100, 100))

    pygame.display.flip()