fix the auto frameskip bug which made throttling explode and cause the emu to run slow!!!

desmume/ChangeLog

@@ -11,6 +11,9 @@
  - Make matrix 4x4 multiply routines use W-coordinate. [zeromus]
  - Add many matrix and vector functions to matrix.c [zeromus]
  - Convert to c++!
+ - Added gfx3d module which emulates the whole GE as part of the core emu. 
+   This is step 1 of making every platform share the same 3d code.
+   Step 2 will be to bring down the windows/cocoa OGLRenderer and make it act as the ogl_collector did. [zeromus]
  Mac OS X port:
  - Fixed: Filenames and paths with unicode characters now work. [Jeff]
  - Fixed: Load state from file button works again. [Jeff]
@@ -53,9 +56,7 @@
  - Added a bunch of crazy templates to the cpu and mmu which speed up a the emu little by optimizing variable accesses [zeromus]
  - Add an arm8 cpu load average calculator [zeromus]
  ? Fix a bug in texture transformation mode 1 [zeromus]
- - Added gfx3d module which emulates the whole GE as part of the core emu. 
-   This is step 1 of making every platform share the same 3d code.
-   Step 2 will be to bring down the windows/cocoa OGLRenderer and make it act as the ogl_collector did. [zeromus]
+ - Fix the buggy auto frameskip logic which made the emu slow to a crawl. Now it runs fast! [zeromus]
     
  
 0.7.3 -> 0.8

desmume/src/windows/DeSmuME_2005.vcproj

@@ -848,6 +848,10 @@
 				RelativePath="..\SPU.cpp"
 				>
 			</File>
+			<File
+				RelativePath=".\throttle.cpp"
+				>
+			</File>
 			<File
 				RelativePath="..\thumb_instructions.cpp"
 				>
@@ -1054,6 +1058,10 @@
 				RelativePath="..\SPU.h"
 				>
 			</File>
+			<File
+				RelativePath=".\throttle.h"
+				>
+			</File>
 			<File
 				RelativePath="..\thumb_instructions.h"
 				>

desmume/src/windows/main.cpp

@@ -55,6 +55,7 @@
 #include "../gdbstub.h"
 #include "colorctrl.h"
 #include "console.h"
+#include "throttle.h"
 
 #include "snddx.h"
 
@@ -401,6 +402,8 @@ DWORD WINAPI run( LPVOID lpParameter)
 
 	 DDCAPS	hw_caps, sw_caps;
 
+	 InitSpeedThrottle();
+
 	if (DirectDrawCreateEx(NULL, (LPVOID*)&lpDDraw, IID_IDirectDraw7, NULL) != DD_OK)
 	{
 		MessageBox(hwnd,"Unable to initialize DirectDraw","Error",MB_OK);
@@ -419,7 +422,7 @@ DWORD WINAPI run( LPVOID lpParameter)
 		return -1;
     }
 
-    //NDS_3D_SetDriver (GPU3D_OPENGL);
+    NDS_3D_SetDriver (GPU3D_OPENGL);
 	 
 	if (!gpu3D->NDS_3D_Init ())
 	{
@@ -577,8 +580,12 @@ DWORD WINAPI run( LPVOID lpParameter)
 
                   framesskipped++;
                }
-
-               if (autoframeskipenab)
+				
+			   while(SpeedThrottle())
+			   {
+			   }
+               
+			   if (autoframeskipenab)
                {
                   framecount++;
 
@@ -591,26 +598,11 @@ DWORD WINAPI run( LPVOID lpParameter)
                   QueryPerformanceCounter((LARGE_INTEGER *)&curticks);
                   diffticks = curticks-lastticks;
 
-                  if ((onesecondticks+diffticks) > (OneFrameTime * (u64)framecount) &&
-                      framesskipped < 9)
-                  {                     
-                     // Skip the next frame
-                     skipnextframe = 1;
- 
-                     // How many frames should we skip?
-                     framestoskip = 1;
-                  }
-                  else if ((onesecondticks+diffticks) < (OneFrameTime * (u64)framecount))
-                  {
-                     // Check to see if we need to limit speed at all
-                     for (;;)
-                     {
-                        QueryPerformanceCounter((LARGE_INTEGER *)&curticks);
-                        diffticks = curticks-lastticks;
-                        if ((onesecondticks+diffticks) >= (OneFrameTime * (u64)framecount))
-                           break;
-                     }
-                  }
+				  if(ThrottleIsBehind() && framesskipped < 9)
+				  {
+					  skipnextframe = 1;
+					  framestoskip = 1;
+				  }
 
                   onesecondticks += diffticks;
                   lastticks = curticks;

desmume/src/windows/throttle.cpp

@@ -0,0 +1,88 @@
+//THIS SPEED THROTTLE IS TAKEN FROM FCEUX.
+//Copyright (C) 2002 Xodnizel
+
+#include "../types.h"
+#include "../debug.h"
+#include "../console.h"
+#include <windows.h>
+
+static u64 tmethod,tfreq;
+static u64 desiredfps = 3920763; //59.8261
+
+static u64 GetCurTime(void)
+{
+	if(tmethod)
+	{
+		u64 tmp;
+
+		/* Practically, LARGE_INTEGER and u64 differ only by signness and name. */
+		QueryPerformanceCounter((LARGE_INTEGER*)&tmp);
+
+		return(tmp);
+	}
+	else
+		return((u64)GetTickCount());
+
+}
+
+void InitSpeedThrottle(void)
+{
+	tmethod=0;
+	if(QueryPerformanceFrequency((LARGE_INTEGER*)&tfreq))
+	{
+		tmethod=1;
+	}
+	else
+		tfreq=1000;
+	tfreq<<=16;    /* Adjustment for fps returned from FCEUI_GetDesiredFPS(). */
+}
+
+static bool behind=false;
+bool ThrottleIsBehind() {
+	return behind;
+}
+
+int SpeedThrottle(void)
+{
+	static u64 ttime,ltime;
+
+	behind = false;
+
+waiter:
+
+	ttime=GetCurTime();
+
+
+	if( (ttime-ltime) < (tfreq/desiredfps) )
+	{
+		u64 sleepy;
+		sleepy=(tfreq/desiredfps)-(ttime-ltime);  
+		sleepy*=1000;
+		if(tfreq>=65536)
+			sleepy/=tfreq>>16;
+		else
+			sleepy=0;
+		if(sleepy>100)
+		{
+			// block for a max of 100ms to
+			// keep the gui responsive
+			Sleep(100);
+			return 1;
+		}
+		Sleep(sleepy);
+		goto waiter;
+	}
+	if( (ttime-ltime) >= (tfreq*4/desiredfps))
+		ltime=ttime;
+	else
+	{
+		ltime+=tfreq/desiredfps;
+
+		if( (ttime-ltime) >= (tfreq/desiredfps) ) // Oops, we're behind!
+		{
+			behind = true;
+			return(1);
+		}
+	}
+	return(0);
+}

desmume/src/windows/throttle.h

@@ -0,0 +1,8 @@
+#ifndef _THROTTLE_H_
+#define _THROTTLE_H_
+
+void InitSpeedThrottle();
+int SpeedThrottle();
+bool ThrottleIsBehind();
+
+#endif