source/gles2glide64/src/Glide64/FrameSkipper.cpp

   1 /* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * *
   2  *   Copyright (C) 2011 yongzh (freeman.yong@gmail.com)                    *
   3  *                                                                         *
   4  *   This program is free software; you can redistribute it and/or modify  *
   5  *   it under the terms of the GNU General Public License as published by  *
   6  *   the Free Software Foundation; either version 2 of the License, or     *
   7  *   (at your option) any later version.                                   *
   8  *                                                                         *
   9  *   This program is distributed in the hope that it will be useful,       *
  10  *   but WITHOUT ANY WARRANTY; without even the implied warranty of        *
  11  *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the         *
  12  *   GNU General Public License for more details.                          *
  13  *                                                                         *
  14  *   You should have received a copy of the GNU General Public License     *
  15  *   along with this program; if not, write to the                         *
  16  *   Free Software Foundation, Inc.,                                       *
  17  *   51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.          *
  18  * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */
  19
  20 #include "FrameSkipper.h"
  21 #include "ticks.h"
  22 #include <stdio.h>
  23
  24 FrameSkipper::FrameSkipper()
  25         : skipType(AUTO), maxSkips(2), targetFPS(60)
  26 {
  27 }
  28
  29 void FrameSkipper::start()
  30 {
  31         initialTicks = 0;
  32         virtualCount = 0;
  33         skipCounter = 0;
  34         oldSkip = 0;
  35 }
  36 #if 0
  37 bool FrameSkipper::hasSkipped()
  38 {
  39         oldSkip = skipCounter;
  40
  41         if (skipType == MANUAL) {
  42                 if (++skipCounter > maxSkips)
  43                         skipCounter = 0;
  44 //printf("frameskipper(Manual): oldSkip=%i, skipCounter=%i, countVI=%i\n", oldSkip, skipCounter, countVI);
  45                 countVI = 0;
  46                 return (oldSkip>0);
  47         }
  48
  49         unsigned int elapsed = ticksGetTicks()/* - initialTicks*/;
  50         int realCount = (elapsed-initialTicks - 4) * targetFPS; // 4ms tolerance
  51         if ((realCount > countVI*1000) && (skipCounter < maxSkips) && (countVI<10)) {
  52                 skipCounter++;
  53 //printf("Skip frame elapsed=%u realCount=%u countVI=%u skipCounter=%i\n", elapsed-initialTicks, realCount, countVI, skipCounter);
  54         } else {
  55 //printf(" Ok  frame elapsed=%u realCount=%u countVI=%u skipCounter=%i\n", elapsed-initialTicks, realCount, countVI, skipCounter);
  56                 skipCounter = 0;
  57                 initialTicks=elapsed;
  58                 virtualCount=0;
  59                 countVI=0;
  60         }
  61 //printf("frameskipper(Auto): oldSkip=%i, skipCounter=%i, countVI=%i, realCount=%u\n", oldSkip, skipCounter, countVI, realCount);
  62         return (oldSkip>0);
  63 }
  64 #else
  65 void FrameSkipper::newFrame()
  66 {
  67         oldSkip = skipCounter;
  68
  69         if (skipType == MANUAL) {
  70                 if (++skipCounter > maxSkips)
  71                         skipCounter = 0;
  72 //printf("frameskipper(Manual): oldSkip=%i, skipCounter=%i, countVI=%i\n", oldSkip, skipCounter, countVI);
  73                 countVI = 0;
  74                 return;
  75         }
  76
  77         unsigned int elapsed = ticksGetTicks()/* - initialTicks*/;
  78         int realCount = (elapsed-initialTicks - 4) * targetFPS; // 4ms tolerance
  79         if ((realCount > countVI*1000) && (skipCounter < maxSkips) && (countVI<10)) {
  80                 skipCounter++;
  81 //printf("Skip frame elapsed=%u realCount=%u countVI=%u skipCounter=%i\n", elapsed-initialTicks, realCount, countVI, skipCounter);
  82         } else {
  83 //printf(" Ok  frame elapsed=%u realCount=%u countVI=%u skipCounter=%i\n", elapsed-initialTicks, realCount, countVI, skipCounter);
  84                 skipCounter = 0;
  85                 initialTicks=elapsed;
  86                 virtualCount=0;
  87                 countVI=0;
  88         }
  89 //printf("frameskipper(Auto): oldSkip=%i, skipCounter=%i, countVI=%i, realCount=%u\n", oldSkip, skipCounter, countVI, realCount);
  90         return;
  91 }
  92 #endif
  93
  94 void FrameSkipper::update()
  95 {
  96 #if 1
  97         if (initialTicks == 0) {
  98                 initialTicks = ticksGetTicks();
  99         }
 100         countVI++;
 101
 102         if (countVI>20) {
 103                 skipCounter=0;          // failsafe...
 104         }
 105 #else
 106         // for the first frame
 107         if (initialTicks == 0) {
 108                 initialTicks = ticksGetTicks();
 109                 return;
 110         }
 111
 112         oldSkip=skipCounter;
 113
 114         if (skipType == MANUAL) {
 115                 if (++skipCounter > maxSkips)
 116                         skipCounter = 0;
 117                 return;
 118         }
 119
 120         unsigned int elapsed = ticksGetTicks()/* - initialTicks*/;
 121         unsigned int realCount = (elapsed-initialTicks) * targetFPS;
 122
 123         virtualCount+=1000;
 124 //      if (realCount >= virtualCount) {
 125                 if (realCount > virtualCount+100 &&
 126                                 /*skipType == AUTO &&*/ skipCounter < maxSkips) {
 127                         skipCounter++;
 128 //printf("Skip frame elapsed=%u initialTicks=%u realCount=%u virtualCound=%u skipCounter=%i\n", elapsed, initialTicks, realCount, virtualCount, skipCounter);
 129                 } else {
 130 //                      virtualCount = realCount;
 131 //                      if (skipType == AUTO)
 132                                 skipCounter = 0;
 133                         initialTicks=elapsed;
 134                         virtualCount=0;
 135                 }
 136 /*      } else {
 137                 skipCounter = 0;
 138                 initialTicks=elapsed;
 139                 virtualCount=0;
 140         }*/
 141 #endif
 142 }