渲染文本并将渲染的文本添加到列表中:
text_surf_list = []
text_surf = font.render("Daniel", True, (255, 255, 0))
text_surf_list.append(text_surf)
text_surf = font.render("Jenny", True, (255, 255, 0))
text_surf_list.append(text_surf)
为文本框定义一个矩形区域:
text_box_rect = pygame.Rect(20, 20, 250, 360)
按顺序遍历列表reversed
。从下向上绘制文本。如果文本不在框中,则从列表中删除它(请参阅如何在迭代时从列表中删除项目?):
text_y = box_rect.bottom - font.get_height()
for text_surf in reversed(text_surf_list[:]):
if text_y <= box_rect.top:
text_surf_list.remove(text_surf)
else:
surf.blit(text_surf, (box_rect.left + 10, text_y))
text_y -= font.get_height()
使用pygame.Surface.set_clip绘制文本框时设置一个临时剪辑区域:
# set clipping
surf.set_clip(box_rect)
# draw text box
# [...]
# disable clipping
surf.set_clip(None)
最小的例子:
import pygame, random
pygame.init()
window = pygame.display.set_mode((400, 400))
clock = pygame.time.Clock()
def draw_scroll_text_box(surf, font, box_rect, text_surf_list):
surf.set_clip(box_rect)
text_y = box_rect.bottom - font.get_height() - 10
for text_surf in reversed(text_surf_list[:]):
if text_y <= box_rect.top:
text_surf_list.remove(text_surf)
else:
surf.blit(text_surf, (box_rect.left + 10, text_y))
text_y -= font.get_height()
pygame.draw.rect(surf, (164, 164, 164), box_rect, 5)
surf.set_clip(None)
font = pygame.font.SysFont(None, 50)
text_box_rect = pygame.Rect(20, 20, 250, 360)
text_surf_list = []
timer_event = pygame.USEREVENT+1
pygame.time.set_timer(timer_event, 200)
background = pygame.Surface(window.get_size())
ts, w, h, c1, c2 = 50, *background.get_size(), (32, 32, 32), (64, 64, 64)
tiles = [((x*ts, y*ts, ts, ts), c1 if (x+y) % 2 == 0 else c2) for x in range((w+ts-1)//ts) for y in range((h+ts-1)//ts)]
[pygame.draw.rect(background, color, rect) for rect, color in tiles]
run = True
while run:
for event in pygame.event.get():
if event.type == pygame.QUIT:
run = False
if event.type == timer_event:
names = ["Daniel", "Jenny", "Patrick", "Sandy", "Bob"]
text_surf = font.render(random.choice(names), True, (255, 255, 0))
text_surf_list.append(text_surf)
window.blit(background, (0, 0))
draw_scroll_text_box(window, font, text_box_rect, text_surf_list)
pygame.display.flip()
clock.tick(60)
pygame.quit()
exit()