如何在pygame中基于鼠标运动绘制矩形

Question

我正试图在pygame中创建一个绘画程序。它要求用户能够通过单击和拖动在屏幕上绘制矩形。

pygame.draw.rect(screeny, (255,255,255), [posi[0], posi[1], e.pos[0]-posi[0], e.pos[1]-posi[1]], 1)
square = pygame.draw.rect(screeny, color, [posi[0], posi[1], e.pos[0]-posi[0], e.pos[1]-posi[1]], 1)
pygame.display.flip()

但是，矩形没有正确显示。如何只绘制一个从鼠标按钮向下点到鼠标按钮向上点的矩形？

Answer 1

我没有足够的代码来处理您的示例。但我能够制作一点代码，创建方框并将其留在屏幕上。

import pygame, sys
from pygame.locals import * //Allows MOUSEMOTION in stead of pygame.MOUSEMOTION
window_size = (800, 600)
clock = pygame.time.Clock()
FPS = 60
mousepos = None
boxes = []
screen = pygame.display.set_mode(window_size)
BLACK = (0, 0, 0)
WHITE = (255, 255, 255)
while 1:
    screen.fill(WHITE)
    events = pygame.event.get()
    for event in events:
        if event.type == QUIT:
            pygame.quit()
            sys.exit()
        if event.type == MOUSEBUTTONDOWN:
            mousepos = [event.pos[0], event.pos[1], 0, 0]
        if event.type == MOUSEBUTTONUP:
            boxes.append(mousepos)
            mousepos = None
        if event.type == MOUSEMOTION and mousepos != None:
            mousepos = [mousepos[0], mousepos[1], event.pos[0] - mousepos[0], event.pos[1] - mousepos[1]]
    for box in boxes:
        pygame.draw.rect(screen, BLACK, box, 1)
    if mousepos != None:
        pygame.draw.rect(screen, BLACK, mousepos, 1)
    pygame.display.update()
    clock.tick(FPS)

我希望这能有所帮助。

注意：小心事件队列，这很危险。切勿将其用于检查按键情况。使用"pygame.key.get_pressed（）[K_（此处键）]"。如果您需要防止触发两次，请创建一个包含以前值的列表，如下所示：

prev = pygame.key.get_pressed()
if prev[K_(key here)] != pygame.key.get_pressed()[K_(Key here)]
    do your stuff...