clock: implement rfps (real frame displayed on screen)

base: display and flip only when needed (might be have some bugs.)

examples/kv/kvrun.py

@@ -6,7 +6,8 @@ from kivy.lang import Builder
 
 class KvApp(App):
     def _print_fps(self, *largs):
-        print 'FPS:', Clock.get_fps()
+        print 'FPS: %2.4f (real draw: %d)' % (
+            Clock.get_fps(), Clock.get_rfps())
     def build(self):
         Clock.schedule_interval(self._print_fps, 1)
         return Builder.load_file(self.options['filename'])

kivy/base.py

@@ -12,6 +12,7 @@ from kivy.logger import Logger
 from kivy.exceptions import ExceptionManager
 from kivy.clock import Clock
 from kivy.input import TouchFactory, kivy_postproc_modules
+from kivy.graphics import GraphicContext
 
 # private vars
 EventLoop               = None
@@ -211,7 +212,9 @@ class EventLoopBase(object):
         self.dispatch_input()
 
         window = self.window
-        if window:
+        need_redraw = GraphicContext.instance().need_redraw
+        if window and need_redraw:
+            Clock.tick_draw()
             window.dispatch('on_draw')
             window.dispatch('on_flip')
 

kivy/c_ext/graphics_context.pxd

@@ -7,7 +7,7 @@ cdef class GraphicContext:
     cdef readonly int need_flush
     cdef Shader _default_shader
     cdef object _default_texture
-    cdef int need_redraw
+    cdef int _need_redraw
 
     cpdef post_update(self)
     cpdef finish_frame(self)

kivy/c_ext/graphics_context.pyx

@@ -45,18 +45,22 @@ cdef class GraphicContext:
         self.journal = set()
         self.need_flush = 0
         self._default_shader = None
+        self._need_redraw = 1
 
     def __init__(self):
         # create initial state
         self.reset()
         self.save()
-        self.need_redraw = 1
+
+    property need_redraw:
+        def __get__(self):
+            return self._need_redraw
 
     cpdef post_update(self):
-        self.need_redraw = 1
+        self._need_redraw = 1
 
     cpdef finish_frame(self):
-        self.need_redraw = 0
+        self._need_redraw = 0
         err = glGetError()
         if err:
             Logger.warning('GContext: GL Error while drawing frame: %d' % err)

kivy/clock.py

@@ -17,8 +17,9 @@ If the callback return False, the schedule will be removed.
 
 __all__ =  ('Clock', )
 
-import time
+from time import time, sleep
 from kivy.weakmethod import WeakMethod
+from kivy.config import Config
 
 class _Event(object):
 
@@ -63,16 +64,19 @@ class _Event(object):
 
 class ClockBase(object):
     '''A clock object, that support events'''
-    __slots__ = ('_dt', '_last_fps_tick', '_last_tick', '_fps',
-            '_fps_counter', '_events')
+    __slots__ = ('_dt', '_last_fps_tick', '_last_tick', '_fps', '_rfps',
+            '_fps_counter', '_rfps_counter', '_events', '_max_fps')
 
     def __init__(self):
         self._dt = 0.0001
-        self._last_tick = time.time()
+        self._last_tick = time()
         self._fps = 0
+        self._rfps = 0
         self._fps_counter = 0
+        self._rfps_counter = 0
         self._last_fps_tick = None
         self._events = []
+        self._max_fps = float(Config.getint('graphics', 'fps'))
 
     @property
     def frametime(self):
@@ -83,8 +87,16 @@ class ClockBase(object):
     def tick(self):
         '''Advance clock to the next step. Must be called every frame.
         The default clock have the tick() function called by Kivy'''
+
+        # do we need to sleep ?
+        if self._max_fps > 0:
+            fps = self._max_fps
+            s = 1 / fps - (time() - self._last_tick)
+            if s > 0:
+                sleep(s)
+
         # tick the current time
-        current = time.time()
+        current = time()
         self._dt = current - self._last_tick
         self._fps_counter += 1
         self._last_tick = current
@@ -93,19 +105,37 @@ class ClockBase(object):
         if self._last_fps_tick == None:
             self._last_fps_tick = current
         elif current - self._last_fps_tick > 1:
-            self._fps = self._fps_counter / float(current - self._last_fps_tick)
+            d = float(current - self._last_fps_tick)
+            self._fps = self._fps_counter / d
+            self._rfps = self._rfps_counter
             self._last_fps_tick = current
             self._fps_counter = 0
+            self._rfps_counter = 0
 
         # process event
         self._process_events()
 
         return self._dt
 
+    def tick_draw(self):
+        '''Tick the drawing counter
+        '''
+        self._rfps_counter += 1
+
     def get_fps(self):
-        '''Get the current FPS calculated by the clock'''
+        '''Get the current FPS calculated by the clock
+        '''
         return self._fps
 
+    def get_rfps(self):
+        '''Get the current "real" FPS calculated by the clock.
+        This counter reflect the real frame displayed on the screen.
+
+        In contrary to get_fps(), this function return a counter of the number
+        of frame, not a average of frame per seconds
+        '''
+        return self._rfps
+
     def get_time(self):
         '''Get the last tick made by the clock'''
         return self._last_tick

kivy/core/window/window_pygame.py

@@ -7,7 +7,6 @@ __all__ = ('WindowPygame', )
 from . import WindowBase
 
 import os
-from time import sleep, time
 from kivy.config import Config
 from kivy.clock import Clock
 from kivy.exceptions import ExceptionManager
@@ -138,17 +137,6 @@ class WindowPygame(WindowBase):
         pygame.display.flip()
         super(WindowPygame, self).flip()
 
-        # do software vsync if asked
-        # FIXME: vsync is surely not 60 for everyone
-        # this is not a real vsync. this must be done by driver...
-        # but pygame can't do vsync on X11, and some people
-        # use hack to make it work under darwin...
-        fps = self._fps
-        if fps > 0:
-            s = 1 / fps - (time() - Clock.get_time())
-            if s > 0:
-                sleep(s)
-
     def toggle_fullscreen(self):
         if self.flags & pygame.FULLSCREEN:
             self.flags &= ~pygame.FULLSCREEN

kivy/data/style.kv

@@ -8,7 +8,7 @@
 			source: 'data/images/button.png'
 	Label:
 		text: root.text
-		font_size: 18
+		font_size: 12
 		canvas:
 			Color:
 				rgb: (1, 1, 1)