proper timing and frameskip code, turbo works properly

source/ngc/fceugx.cpp

@@ -52,6 +52,7 @@ extern void __exception_setreload(int t);
 }
 
 static int fskipc = 0;
+static int fskip = 0;
 static uint8 *gfx=0;
 static int32 *sound=0;
 static int32 ssize=0;
@@ -62,6 +63,7 @@ int ResetRequested = 0;
 int ExitRequested = 0;
 char appPath[1024] = { 0 };
 int frameskip = 0;
+int turbomode = 0;
 unsigned char * nesrom = NULL;
 
 /****************************************************************************
@@ -345,16 +347,46 @@ int main(int argc, char *argv[])
 		SetPalette();
 		FCEUI_DisableSpriteLimitation(GCSettings.spritelimit ^ 1);
 
+		fskip=0;
 		fskipc=0;
+		frameskip=0;
 
 		while(1) // emulation loop
 		{
-			#ifdef FRAMESKIP
-			fskipc=(fskipc+1)%(frameskip+1);
-			#endif
+			fskip = 0;
+			
+			if(turbomode)
+			{
+				fskip = 1;
+								
+				if(fskipc >= 18)
+				{
+					fskipc = 0;
+					fskip = 0;
+				}
+				else
+				{
+					fskipc++;
+				}
+			}
+			else if(frameskip > 0)
+			{
+				fskip = 1;
+				
+				if(fskipc >= frameskip)
+				{
+					fskipc = 0;
+					fskip = 0;
+				}
+				else
+				{
+					fskipc++;
+				}
+			}
 
-			FCEUI_Emulate(&gfx, &sound, &ssize, fskipc);
+			FCEUI_Emulate(&gfx, &sound, &ssize, fskip);
 			FCEUD_Update(gfx, sound, ssize);
+			SyncSpeed();
 
 			if(ResetRequested)
 			{

source/ngc/fceugx.h

@@ -104,6 +104,7 @@ extern int ShutdownRequested;
 extern int ExitRequested;
 extern char appPath[];
 extern int frameskip;
+extern int turbomode;
 extern bool romLoaded;
 
 #endif

source/ngc/fileop.cpp

@@ -634,9 +634,7 @@ LoadFile (char * rbuffer, char *filepath, u32 length, bool silent)
 	u32 readsize = 0;
 	int retry = 1;
 	int device;
-	
-	printf("loading %s\n", filepath);
-	
+
 	if(!FindDevice(filepath, &device))
 		return 0;
 

source/ngc/gcvideo.cpp

@@ -199,7 +199,7 @@ static GXRModeObj *tvmodes[2] = {
  * change frame timings depending on whether ROM is NTSC or PAL
  ***************************************************************************/
 
-static long long normaldiff;
+static u32 normaldiff;
 
 void setFrameTimer()
 {
@@ -207,17 +207,28 @@ void setFrameTimer()
 		normaldiff = 20000; // 50hz
 	else
 		normaldiff = 16667; // 60hz
-
 	prev = gettime();
 }
 
-static void SyncSpeed()
+void SyncSpeed()
 {
 	now = gettime();
-	while (diff_usec(prev, now) < normaldiff)
+	
+	if(turbomode)
 	{
-		now = gettime();
-		usleep(50);
+		// do nothing
+	}
+	else if (diff_usec(prev, now) > normaldiff)
+	{
+		frameskip++;
+	}
+	else // ahead, so hold up
+	{	
+		while (diff_usec(prev, now) < normaldiff)
+		{
+			now = gettime();
+			usleep(50);
+		}
 	}
 	prev = now;
 }
@@ -242,7 +253,7 @@ vbgetback (void *arg)
 {
 	while (1)
 	{
-		SyncSpeed();
+		VIDEO_WaitVSync ();
 		LWP_SuspendThread (vbthread);
 	}
 

source/ngc/gcvideo.h

@@ -25,6 +25,7 @@ void StopGX();
 void ResetVideo_Emu ();
 void RenderFrame(unsigned char *XBuf);
 void setFrameTimer();
+void SyncSpeed();
 void zoom (float speed);
 void zoom_reset ();
 void SetPalette();

source/ngc/pad.cpp

@@ -624,9 +624,9 @@ void GetJoy()
 	// Turbo mode
 	// RIGHT on c-stick and on classic ctrlr right joystick
 	if(userInput[0].pad.substickX > 70 || userInput[0].WPAD_Stick(1,0) > 70)
-		frameskip = 1;
+		turbomode = 1;
 	else
-		frameskip = 0;
+		turbomode = 0;
 
 	// request to go back to menu
 	if(MenuRequested())