如何在不改变透明度的情况下更改Pygame中的图像颜色？

Question

这听起来像是一件简单的事情，但我很挣扎。 我有一个名为“零”的透明中心的矩形的PNG图像。我想改变图像可见部分的颜色。为了尝试和改变它，我尝试过使用“zero.fill”，但没有选择，我尝试只更改非透明部分，或者将新颜色与旧颜色合并，并保持这种状态。 我并不热衷于安装numpy，因为我希望将完成的程序带给没有它的朋友。任何简单的建议欢迎。

Answer 1

我有一个例子，可以使用每像素alpha表面，也可以是半透明的。 fill函数只是循环遍历曲面的像素，并将它们设置为新颜色，但保持它们的alpha值。对于具有多个曲面的每一帧，可能不建议这样做。 （按F，G，H改变颜色。）

import sys 
import pygame as pg 


def fill(surface, color): 
    """Fill all pixels of the surface with color, preserve transparency.""" 
    w, h = surface.get_size() 
    r, g, b, _ = color 
    for x in range(w): 
     for y in range(h): 
      a = surface.get_at((x, y))[3] 
      surface.set_at((x, y), pg.Color(r, g, b, a)) 


def main(): 
    screen = pg.display.set_mode((640, 480)) 
    clock = pg.time.Clock() 

    # Uncomment this for a non-translucent surface. 
    # surface = pg.Surface((100, 150), pg.SRCALPHA) 
    # pg.draw.circle(surface, pg.Color(40, 240, 120), (50, 50), 50) 
    surface = pg.image.load('bullet2.png').convert_alpha() 
    surface = pg.transform.rotozoom(surface, 0, 2) 

    done = False 

    while not done: 
     for event in pg.event.get(): 
      if event.type == pg.QUIT: 
       done = True 
      if event.type == pg.KEYDOWN: 
       if event.key == pg.K_f: 
        fill(surface, pg.Color(240, 200, 40)) 
       if event.key == pg.K_g: 
        fill(surface, pg.Color(250, 10, 40)) 
       if event.key == pg.K_h: 
        fill(surface, pg.Color(40, 240, 120)) 

     screen.fill(pg.Color('lightskyblue4')) 
     pg.draw.rect(screen, pg.Color(40, 50, 50), (210, 210, 50, 90)) 
     screen.blit(surface, (200, 200)) 

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


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

Answer 2

在这个版本中，可见光和透明部分是倒过来原来的问题按ANKUR的建议。 这里是必不可少的工作代码：

import pygame, sys 
from pygame.locals import * 
pygame.init() 

def load_image(name): 
    image = pygame.image.load(name).convert() 
    return image 

def resize(obj, w, h): 
    global scale 
    return pygame.transform.scale(obj, (int(w * scale), int(h * scale))) 


pink = (255, 0, 160) 
red = (255, 0, 0) 
peach = (255, 118, 95) 
blue = (0, 0, 255) 
blue_1 = (38, 0, 160) 
dark_yellow = (255, 174, 0) 
green = (38, 137, 0) 
orange = (255, 81, 0) 
colour = [pink, red, peach, blue, blue_1, dark_yellow, green, orange, green] 
clock = pygame.time.Clock() 
scale = 4 
screen = pygame.display.set_mode((292 * scale, 240 * scale),0, 32) 
banner = load_image("banner.png") #292x35 
zero = load_image("zero.png") #5x7 
c = 0 
while True: 
    for event in pygame.event.get(): 
     if event.type == QUIT: 
      pygame.quit() 
      sys.exit() 
    rgb = colour[c] 
    c = c + 1 
    if c > 7: 
     c = 0 
    pygame.draw.line(banner, rgb, (53, 21), (53, 27), 5) #line the same size as zero image 
    banner.blit(zero, (51, 21)) #blit image with transparency over line 
    large_banner = resize(banner, 292, 35) 
    screen.blit(large_banner, (0, 0)) 
    clock.tick(120) 
    pygame.display.flip() 

pygame.quit() 
sys.exit()