在pygame中的透明表面上渲染反锯齿文本

Question

我正在制作一个函数，它将一个字符串分解成行，并返回一个表面，每行渲染为前一行的下方。

例如：

Line1\nLine 2

呈现为：

Line1 
Line2 

不管怎样，我的问题是，我不能返回正确的透明表面到调用函数。我尝试过使用颜色键，但它不适用于消除锯齿的文本。有什么办法可以做到这一点？感谢您的回答。

我的代码：（目前周围留下文字丑陋的紫影）

def render_message(messages): 
    surfaces = [] 
    height = 0 
    max_width = 0 

    for message in messages.split('\n'): 
     surf = FONT.render(message, True, (0, 0, 0)) 
     surfaces.append(surf) 
     height += surf.get_height() + 5 
     if surf.get_width() > max_width: 
      max_width = surf.get_width() 

    result = pygame.Surface((max_width, height)) 
    result.fill((255, 0, 255)) 
    result.set_colorkey((255, 0, 255)) 

    top = 0 
    for surface in surfaces: 
     result.blit(surface, (max_width/2-surface.get_width()/2, top)) 
     top += surface.get_height() + 5 

    return result 

Answer 1

发表了第二个答案，因为这更复杂，人们可能想看到两者。

• 1，2减少/增加字体大小
• space切换BG

我离开文本换行了。编辑parse_text()以创建您想要的文本列表。

import pygame 
from pygame import Surface 
from pygame.locals import * 
# Todo: remove font object from TextLine() , to TextWall(). Then share a list of font's with any line. 

"""Example of multi-line text class, with alpha transparency.""" 
lorem = """Lorem ipsum dolor sit amet, consectetur adipiscing elit. Sed aliquet 
tellus eros, eu faucibus dui. Phasellus eleifend, massa id ornare sodales, est urna 
congue tellus, vitae varius metus nunc non enim. Mauris elementum, arcu vitae tempor euismod, justo turpis malesuada est, sed dictum nunc nulla nec mauris. Cras felis eros, elementum vitae sollicitudin in, elementum et augue. Proin eget nunc at dui congue pretium. Donec ut ipsum ut lacus mollis tristique. In pretium varius dui eu dictum. 

Proin pulvinar metus nec mi semper semper. Pellentesque habitant morbi tristique 
senectus et netus et malesuada fames ac turpis egestas. Proin in diam odio. Vestibulum 
at neque sed ante sodales eleifend quis id dui. Mauris sollicitudin, metus a semper consectetur, 
est lectus varius erat, sit amet ultrices tortor nisi id justo. Aliquam elementum vestibulum dui ut auctor. Mauris commodo sapien vitae augue tempus sagittis. Morbi a nibh lectus, sed porta nibh. Donec et est ac dui sodales aliquet tristique et arcu. Nullam enim felis, posuere vel rutrum eu, euismod a purus. Morbi porta cursus libero, id rutrum elit lacinia vitae. 

In condimentum ultrices ipsum, ut convallis odio egestas et. Cras at egestas elit. Morbi 
quis neque ligula. Sed tempor, sem at fringilla rhoncus, diam quam mollis nisi, vitae semper 
mi massa sit amet tellus. Vivamus congue commodo ornare. Morbi et mi non sem malesuada rutrum. Etiam est purus, interdum ut placerat sit amet, tempus eget eros. Duis eget augue quis diam facilisis blandit. Ut vulputate adipiscing eleifend. """ 

class TextLine(object): 
    # Manages drawing and caching a single line of text 
    # You can make font size, .color_fg etc be properties so they *automatically* toggle dirty bool. 
    def __init__(self, font=None, size=16, text="hi world"):   
     self.font_name = font 
     self.font_size = size 
     self.color_fg = Color("white") 
     self.color_bg = Color("gray20") 

     self._aa = True 
     self._text = text     
     self.font = pygame.font.Font(font, size) 
     self.screen = pygame.display.get_surface() 

     self.dirty = True 
     self.image = None 
     self._render() 

    def _render(self): 
     # render for cache 
     """no AA = automatic transparent. With AA you need to set the color key too""" 
     self.dirty = False   
     self.image = self.font.render(self._text, self.aa, self.color_fg)    
     self.rect = self.image.get_rect() 

    def draw(self): 
     # Call this do draw, always prefers to use cache 
     if self.dirty or (self.image is None): self._render() 
     self.screen.blit(self.image, self.rect)   

    @property 
    def text(self): 
     return self._text 

    @text.setter 
    def text(self, text): 
     self.dirty = True 
     self._text = text 

    @property 
    def aa(self): return self._aa 

    @aa.setter 
    def aa(self, aa): 
     self.dirty = True 
     self._aa = aa 

class TextWall(object): 
    # Manages multiple lines of text/paragraphs. 
    def __init__(self, font=None, size=16): 
     self.font = font 
     self.font_size = size   
     self.offset = Rect(20,20,1,1) # offset of whole wall 

     self.screen = pygame.display.get_surface() 
     self.dirty = True 
     self.text_lines = [] 
     self._text_paragraph = "Empty\nText" 
     self._render() 

    def _render(self): 
     # render list 
     self.dirty = False 
     self.text_lines = [ TextLine(self.font, self.font_size, line) for line in self._text_paragraph ]   

     # offset whole paragraph 
     self.text_lines[0].rect.top = self.offset.top 

     # offset the height of each line 
     prev = Rect(0,0,0,0)   
     for t in self.text_lines: 
      t.rect.top += prev.bottom 
      t.rect.left = self.offset.left 
      prev = t.rect 

    def parse_text(self, text): 
     # parse raw text to something usable 
     self._text_paragraph = text.split("\n") 
     self._render() 

    def draw(self): 
     # draw with cached surfaces  
     if self.dirty: self._render() 
     for text in self.text_lines: text.draw() 

    @property 
    def font_size(self): 
     return self._font_size 

    @font_size.setter 
    def font_size(self, size): 
     self.dirty = True 
     self._font_size = size 

    @property 
    def text(self): 
     return self._text_paragraph 

    @text.setter 
    def text(self, text_paragraph): 
     self.dirty = True 
     self.parse_text(text_paragraph) 

class Game(): 
    done = False 
    def __init__(self): 
     pygame.init() 
     self.screen = pygame.display.set_mode ((640,480)) 
     self.text = Surface([200,100]) 

     self.text_wall = TextWall() 
     self.toggle_bg = True 

     self.text_wall.parse_text(lorem) 

    def loop(self): 
     while not self.done: 
      self.handle_events() 
      self.draw() 

    def draw(self): 
     if self.toggle_bg: bg = Color("gray60") 
     else: bg = Color("gray20") 

     self.screen.fill(bg)   
     self.text_wall.draw()   
     pygame.display.update() 

    def handle_events(self): 
     for event in pygame.event.get(): 
      if event.type == pygame.QUIT: self.done = True 

      elif event.type == KEYDOWN: 
       if event.key == K_ESCAPE: self.done = True     
       elif event.key == K_SPACE: self.toggle_bg = not self.toggle_bg 
       elif event.key == K_1: self.text_wall.font_size -= 3 
       elif event.key == K_2: self.text_wall.font_size += 3 

if __name__ == "__main__": 
    g = Game() 
    g.loop() 

Answer 2

得到它的工作。主要不是我发现的是：没有AA =自动透明。使用AA您也需要设置颜色键

这里是一个工作示例，它切换BG以确保其透明。

import pygame 
from pygame import Surface 
#from pygame.locals import Rect, Color 
from pygame.locals import * 

class TextWall(): 
    def __init__(self, font=None, size=300): 
     # for simplicity uses one font, one size for now. 
     # You also can make font size, .text, etc be properties so they *automatically* toggle dirty bool. 
     self.font_name = font 
     self.font_size = size 
     self.color_fg = Color("white") 
     self.color_bg = Color("gray20") 
     self.aa = True 
     self.text = "hi world" 

     self.dirty = True 
     self.font = pygame.font.Font(font, size) 
     self.screen = pygame.display.get_surface() 


    def _render(self): 
     # re-render 
     """no AA = automatic transparent. With AA you need to set the color key too""" 
     self.dirty = False   
     self.text1 = self.font.render(self.text, self.aa, self.color_fg)    
     self.rect1 = self.text1.get_rect() 

    def draw(self): 
     # blits use cached surface, until text change makes it dirty 
     if self.dirty or self.text1 is None: self._render() 
     self.screen.blit(self.text1, self.rect1) 

    def text(self, text): 
     self.dirty = True 
     self.text_message = text # parse 

class Game(): 
    done = False 
    def __init__(self): 
     pygame.init() 
     self.screen = pygame.display.set_mode ((640,480)) 
     self.text = Surface([200,100]) 

     self.text_wall = TextWall() 
     self.toggle_bg = True 
    def loop(self): 
     while not self.done: 
      self.handle_events() 
      self.draw() 

    def draw(self): 
     if self.toggle_bg: bg = Color("darkred") 
     else: bg = Color("gray20") 

     self.screen.fill(bg)   
     self.text_wall.draw()   
     pygame.display.update() 

    def handle_events(self): 
     for event in pygame.event.get(): 
      if event.type == pygame.QUIT: self.done = True 

      elif event.type == KEYDOWN: 
       if event.key == K_ESCAPE: self.done = True     
       elif event.key == K_SPACE: self.toggle_bg = not self.toggle_bg 
       elif event.key == K_a: 
        self.text_wall.aa = not self.text_wall.aa 
        self.text_wall.dirty = True 


if __name__ == "__main__": 
    g = Game() 
    g.loop() 

编辑：改进的代码，使用alpha通道，而不是set_colorkey。