Question

这个问题真的很难问，但我知道Stack Overflow的你们都是最聪明的人。

我完全不知道为什么会出现这个问题（我非常擅长Python和Pygame，所以任何有关如何改进代码的建议都会因为提高我的技能而受到欢迎）。

我在创造什么：这真是一个噱头项目，我有一个2.5英寸的屏幕（PiTFT）连接到Raspberry Pi，代码正在创建一个打字机效果，在文本正在写入时，移动光标位于文本前面。

挑战1是每次你在pygame中移动一个精灵时，你必须重绘所有内容，否则你会看到一个踪迹，并且由于光标在文本前面移动，结果将如下所示：

我设法通过黑屏/清除屏幕解决了这个问题。但后来我丢失了以前所写的所有信件。所以我创建了一个列表（整个词），我用所有以前写过的字符来填充。每次循环遍历重绘所有以前的书面文本时，我都会使用此列表。所以现在：

如您所见，文字看起来很有趣。它应该是：

[i]初始化......

[i]进入鬼模式...... []

我花了好几个小时才到达这一点 - 代码ALMOST完美无缺！魔术发生在函数print_screen（）中，但是我的代码中的内容是什么导致文本最后包含来自另一行的字母？产品：＆gt;

非常感谢帮助＆lt; 3

以下是整个代码：

import pygame
import time
import os
import sys
from time import sleep
from pygame.locals import *

positionx = 10
positiony = 10
entireword = []
entireword_pos = 10
counter = 0
entire_newline = False


#Sets the width and height of the screen
WIDTH = 320
HEIGHT = 240
speed = 0.05

#Importing the external screen
os.putenv('SDL_FBDEV', '/dev/fb1')
os.putenv('SDL_MOUSEDRV', 'TSLIB')
os.putenv('SDL_MOUSEDEV', '/dev/input/touchscreen')

#Initializes the screen - Careful: all pygame commands must come after the init
pygame.init()

#Sets mouse cursor visibility
pygame.mouse.set_visible(False)
#Sets the screen note: must be after pygame.init()
screen = pygame.display.set_mode((WIDTH, HEIGHT))

# initialize font; must be called after 'pygame.init()' to avoid 'Font not Initialized' error
myfont = pygame.font.SysFont("monospace", 18)

#Class

class cursors(pygame.sprite.Sprite):
    def __init__(self):
        pygame.sprite.Sprite.__init__(self)
        self.image = pygame.Surface((10, 20))
        self.image.fill((0,255,0))
        self.rect = self.image.get_rect()
        self.rect.center = (positionx + 10, positiony + 10)

    def update(self):
        self.rect.x = positionx + 10
        self.rect.y = positiony

#Functions

#Prints to the screen
def print_screen(words, speed):
    rel_speed = speed
    for char in words:
        #speed of writing
        if char == ".":
            sleep(0.3)
        else:
            sleep(rel_speed)

        #re-renders previous written letters
        global entireword

        # Old Typewriter functionality - Changes position of cursor and text a newline

        #Makes sure the previous letters are rendered and not lost
        #xx is a delimter so the program can see when to make a newline and ofcourse ignore writing the delimiter
        entireword.append(char)
        if counter > 0:
            loopcount = 1
            linecount = 0 # This is to which line we are on
            for prev in entireword:
                if prev == 'xx':
                    global linecount
                    global positiony
                    global loopcount
                    linecount = linecount + 1
                    positiony = 17 * linecount
                    loopcount = 1
                if prev != 'xx':  #ignore writing the delimiter
                    pchar = myfont.render(prev, 1, (255,255,0))
                    screen.blit(pchar, (loopcount * 10, positiony))
                    loopcount = loopcount + 1

        if char != 'xx':
            # render text
            letter = myfont.render(char, 1, (255,255,0))
            #blits the latest letter to the screen
            screen.blit(letter, (positionx, positiony))

        # Appends xx as a delimiter to indicate a new line
        if entire_newline == True:
            entireword.append('xx')
            global entire_newline
            entire_newline = False

        global positionx
        positionx = positionx + 10
        all_sprites.update()
        all_sprites.draw(screen)
        pygame.display.flip()
        screen.fill((0,0,0)) # blackens / clears the screen

        global counter
        counter = counter + 1

#Positions cursor at new line
def newline():
    global positionx
    global positiony
    positionx = 10
    positiony = positiony + 17

all_sprites = pygame.sprite.Group()
cursor = cursors()
all_sprites.add(cursor)

#Main loop
running = True
while running:
    global speed
    global entire_newline

    words = "[i] Initializing ..."
    entire_newline = True
    newline()
    print_screen(words,speed)

    words = "[i] Entering ghost mode ..."
    entire_newline = True
    newline()
    print_screen(words,speed)

    #Stops the endless loop if False
    running = False
sleep(10)

Answer 1

很抱歉，如果我没有直接回答您的问题，因为您的代码现在对我来说太混乱了，所以我冒昧地重写您的代码以完成您想要的工作。

这个想法是有两个精灵：

光标，即a）显示在屏幕上，b）跟踪要写的文字和位置
电路板，它基本上只是文本在

注意所有写入逻辑是如何在Cursor类上进行的，我们有一个很好，简单和愚蠢的主循环。

import pygame
import os

#Sets the width and height of the screen
WIDTH = 320
HEIGHT = 240

#Importing the external screen
os.putenv('SDL_FBDEV', '/dev/fb1')
os.putenv('SDL_MOUSEDRV', 'TSLIB')
os.putenv('SDL_MOUSEDEV', '/dev/input/touchscreen')

#Initializes the screen - Careful: all pygame commands must come after the init
pygame.init()
clock = pygame.time.Clock()

#Sets mouse cursor visibility
pygame.mouse.set_visible(False)
#Sets the screen note: must be after pygame.init()
screen = pygame.display.set_mode((WIDTH, HEIGHT))


class Board(pygame.sprite.Sprite):
    def __init__(self):
        pygame.sprite.Sprite.__init__(self)
        self.image = pygame.Surface((WIDTH, HEIGHT))
        self.image.fill((13,13,13))
        self.image.set_colorkey((13,13,13))
        self.rect = self.image.get_rect()
        self.font = pygame.font.SysFont("monospace", 18)

    def add(self, letter, pos):
        s = self.font.render(letter, 1, (255, 255, 0))
        self.image.blit(s, pos)

class Cursor(pygame.sprite.Sprite):
    def __init__(self, board):
        pygame.sprite.Sprite.__init__(self)
        self.image = pygame.Surface((10, 20))
        self.image.fill((0,255,0))
        self.text_height = 17
        self.text_width = 10
        self.rect = self.image.get_rect(topleft=(self.text_width, self.text_height))
        self.board = board
        self.text = ''
        self.cooldown = 0
        self.cooldowns = {'.': 12,
                        '[': 18,
                        ']': 18,
                        ' ': 5,
                        '\n': 30}

    def write(self, text):
        self.text = list(text)

    def update(self):
        if not self.cooldown and self.text:
            letter = self.text.pop(0)
            if letter == '\n':
                self.rect.move_ip((0, self.text_height))
                self.rect.x = self.text_width
            else:
                self.board.add(letter, self.rect.topleft)
                self.rect.move_ip((self.text_width, 0))
            self.cooldown = self.cooldowns.get(letter, 8)

        if self.cooldown:
            self.cooldown -= 1

all_sprites = pygame.sprite.Group()
board = Board()
cursor = Cursor(board)
all_sprites.add(cursor, board)

text = """[i] Initializing ...
[i] Entering ghost mode ...

done ...

"""

cursor.write(text)

#Main loop
running = True
while running:

    for e in pygame.event.get():
        if e.type == pygame.QUIT:
            running = False

    all_sprites.update()
    screen.fill((0, 0, 0))
    all_sprites.draw(screen)
    pygame.display.flip()
    clock.tick(60)

打字机效果Pygame

1 个答案: