如何查找Pygame中圆的x，y坐标

Question

我目前正在尝试创建一个数字速度计。由于尝试控制拨号时遇到问题，该项目已陷入戛然而止。我的可变radial_pos旨在计算出准确的x，y坐标的速度计的每个刻度的，并且如果用户按下K_UP，radial_pos将增加1，以显示速度表的下一个勾号。不过，恐怕自从我学习了找到圆的坐标这个概念以来，这已经太多年了，更别说足够理解它，从而能够相应地增加它。这是我到目前为止的代码：

import pygame, sys 
from pygame.locals import * 

pygame.init() 

#Screen Resolution 
width = 1080 
height = 720 

#Instrument Characteristics 
color = (255,255,255) 
background = (0,0,0) 

radius_speedometer = 100 
weight_speedometer = radius_speedometer-5 

#Window Measurements 
screen= pygame.display.set_mode((width,height),0,32) 
pos_center_x = width/2 
pos_center_y = height/2 

#Speedometer Dial Position 
pos_speedometer_dial_x = pos_center_x - 60 
pos_speedometer_dial_y = pos_center_y +60 

#Radial Position (hint: ticks on the clock) 
''' 
radial_pos = ... 
''' 

while True: 
    for event in pygame.event.get(): 
     if event.type==QUIT: 
      pygame.quit() 
      sys.exit() 

     if event.type==KEYDOWN: 
      if event.key==K_DOWN: 
       radial_pos=-1 
      if event.key==K_UP: 
       radial_pos=+1 

     if event.type==KEYUP: 
      if event.key==K_DOWN: 
       radial_pos=0 
      if event.key==K_UP: 
       radial_pos=0 

    screen.lock() 

    #Speedometer Ring 
    pygame.draw.circle(screen, color, (pos_center_x,pos_center_y),  radius_speedometer) 
    pygame.draw.circle(screen, background, (pos_center_x,pos_center_y), weight_speedometer) 

    #Speedometer Dial 
    pygame.draw.line(screen, color, (pos_center_x,pos_center_y), (pos_speedometer_dial_x, pos_speedometer_dial_y),5) 

    screen.unlock() 

    pygame.display.update() 

如果任何人有这个问题上的任何意见，这将不胜感激。感谢您的时间。

Answer 1

看来我终于找到了一个很好的解决方案。下面是最新代码：

import pygame, sys 
from pygame.locals import * 
from math import * 

pygame.init() 

#Screen Resolution 
width = 1080 
height = 720 

#Instrument Characteristics 
color = (255,255,255) 
background = (0,0,0) 

radius_speedometer = 100 
weight_speedometer = radius_speedometer-5 

#Window Measurements 
screen= pygame.display.set_mode((width,height),0,32) 
pos_center_x = width/2 
pos_center_y = height/2 

#Speedometer Dial Position 
pos_speedometer_dial_x = pos_center_x - 60 
pos_speedometer_dial_y = pos_center_y +60 

#Radial Position (hint: ticks on the clock) 
radial_pos = 70 
move_rad = 0 

while True: 
    for event in pygame.event.get(): 
     if event.type==QUIT: 
      pygame.quit() 
      sys.exit() 


     if event.type==KEYDOWN: 
      if event.key==K_DOWN: 
       move_rad=-0.01 
      if event.key==K_UP: 
       move_rad=+0.01 

     if event.type==KEYUP: 
      if event.key==K_DOWN: 
       move_rad=-0.05 
      if event.key==K_UP: 
       move_rad=-0.005 

    angle = 2.0*pi*radial_pos/120.0 

    radial_pos+=move_rad 

    pos_speedometer_dial_x = pos_center_x + (radius_speedometer-10)*sin(angle) 
    pos_speedometer_dial_y = pos_center_y - (radius_speedometer-10)*cos(angle) 

    screen.lock() 

    #Speedometer Ring 
    pygame.draw.circle(screen, color, (pos_center_x,pos_center_y), radius_speedometer) 
    pygame.draw.circle(screen, background, (pos_center_x,pos_center_y), weight_speedometer) 

    #Speedometer Dial 
    pygame.draw.line(screen, color, (pos_center_x,pos_center_y), (pos_speedometer_dial_x, pos_speedometer_dial_y),5) 

    screen.unlock() 

    pygame.display.update() 

它并不完美（如无零还），但是我们现在更接近完成仪表组的第一件乐器！