检测鼠标点击不同表面上的圆圈

Question

如何检查是否单击了单独表面上的圆圈？

from pygame.locals import *
import pygame, sys, math

pygame.init()
screen = pygame.display.set_mode((640, 480))

s = pygame.Surface((100, 100))
s.fill((255, 0, 0))
s_rect = s.get_rect(center = (300, 300))

running = True
while running:
    for event in pygame.event.get():
        if event.type == QUIT:
            running = False
        if event.type == pygame.MOUSEBUTTONDOWN:
            
            x = pygame.mouse.get_pos()[0]
            y = pygame.mouse.get_pos()[1]

            sqx = (x - 20)**2
            sqy = (y - 20)**2

            if math.sqrt(sqx + sqy) < 20:
                print ('inside')

    screen.fill((200, 200, 255))
    screen.blit(s, s_rect)
    pygame.draw.circle(s, (0, 0, 0), (20, 20), 20) # this doesn't work

    pygame.draw.circle(screen, (0, 0, 0), (20, 20), 20) # this works
    
    pygame.display.update()
    
pygame.quit()

当我运行这段代码时没有任何反应。但是，如果我在主屏幕上画圆圈，它就可以了！！！

Answer 1

您必须计算鼠标相对于 Surface 的位置。

你有两种可能。从鼠标位置减去 Surface 在屏幕上的（左上）位置：

x = event.pos[0] - s_rect.left
y = event.pos[1] - s_rect.top

或者将Surface在屏幕上的（左上）位置添加到圆心：

sqx = (x - (s_rect.left + 20))**2
sqy = (y - (s_rect.top + 20))**2

完整示例

from pygame.locals import *
import pygame, math

pygame.init()
screen = pygame.display.set_mode((640, 480))

s = pygame.Surface((100, 100))
s.fill((255, 0, 0))
s_rect = s.get_rect(center = (300, 300))
clicked = False

running = True
while running:
    for event in pygame.event.get():
        if event.type == QUIT:
            running = False
        if event.type == pygame.MOUSEBUTTONDOWN:
            
            x = event.pos[0]
            y = event.pos[1]

            sqx = (x - (s_rect.left + 20))**2
            sqy = (y - (s_rect.top + 20))**2

            if math.sqrt(sqx + sqy) < 20:
                clicked = not clicked
                print ('inside')

    screen.fill((200, 200, 255))
    color = (255, 255, 255) if clicked else (0, 0, 0)
    pygame.draw.circle(s, color, (20, 20), 20)
    screen.blit(s, s_rect)
    pygame.display.update()
    
pygame.quit()

检测鼠标点击不同表面上的圆圈

Detect mouse click on circle that is on different surface

geometry

pygame

shapes