src/pgu/timer.py

   1 """A timer for games with set-rate FPS.
   2 """
   3
   4 import pygame
   5
   6 class Timer:
   7     """A timer for games with set-rate FPS.
   8
   9     <pre>Timer(fps)</pre>
  10     """
  11
  12     def __init__(self,fps):
  13         if fps == 0:
  14             self.tick = self._blank
  15             return
  16         self.wait = 1000/fps
  17         self.nt = pygame.time.get_ticks()
  18         pygame.time.wait(0)
  19
  20     def _blank(self):
  21         pass
  22
  23     def tick(self):
  24         """Wait correct amount of time each frame.  Call this once per frame.
  25
  26         <pre>Timer.tick()</pre>
  27         """
  28         self.ct = pygame.time.get_ticks()
  29         if self.ct < self.nt:
  30             pygame.time.wait(self.nt-self.ct)
  31             self.nt+=self.wait
  32         else:
  33             self.nt = pygame.time.get_ticks()+self.wait
  34
  35
  36 class Speedometer:
  37     """A timer replacement that returns out FPS once a second.
  38     <pre>Speedometer()</pre>
  39
  40     <strong>Attributes</strong>
  41     <dl>
  42     <dt>fps <dd>always set to the current FPS
  43     </dl>
  44     """
  45     def __init__(self):
  46         self.frames = 0
  47         self.st = pygame.time.get_ticks()
  48         self.fps = 0
  49
  50     def tick(self):
  51         """ Call this once per frame.
  52
  53         <pre>Speedometer.tick()</pre>
  54         """
  55         r = None
  56         self.frames += 1
  57         self.ct = pygame.time.get_ticks()
  58         if (self.ct - self.st) >= 1000:
  59             r = self.fps = self.frames
  60             #print "%s: %d fps"%(self.__class__.__name__,self.fps)
  61             self.frames = 0
  62             self.st += 1000
  63         pygame.time.wait(0) #NOTE: not sure why, but you gotta call this now and again
  64         return r
  65
  66
  67
  68 # vim: set filetype=python sts=4 sw=4 noet si :