From 1c6851c3f0fd22da102bd411fd6ded048c5fca9f Mon Sep 17 00:00:00 2001
From: Matthew Budd <mjbudd77@gmail.com>
Date: Mon, 10 Aug 2020 21:04:42 -0400
Subject: [PATCH] Bug fix for SDL joystick not working using SDL video driver.
 By default SDL joystick inputs are ignored if the SDL window does not have
 focus. Set SDL HINT to allow for background joystick inputs to accepted (i.e.
 joystick inputs come through even though window not in focus).

---
 src/drivers/Qt/fceuWrapper.cpp |  4 +++
 src/drivers/sdl/sdl.cpp        | 45 ++++++++++++++++++++--------------
 2 files changed, 30 insertions(+), 19 deletions(-)

diff --git a/src/drivers/Qt/fceuWrapper.cpp b/src/drivers/Qt/fceuWrapper.cpp
index 5e2ea31d..886e08d4 100644
--- a/src/drivers/Qt/fceuWrapper.cpp
+++ b/src/drivers/Qt/fceuWrapper.cpp
@@ -438,6 +438,10 @@ int  fceuWrapperInit( int argc, char *argv[] )
 		printf("Could not initialize SDL: %s.\n", SDL_GetError());
 		exit(-1);
 	}
+	if ( SDL_SetHint( SDL_HINT_JOYSTICK_ALLOW_BACKGROUND_EVENTS, "1" ) == SDL_FALSE )
+	{
+		printf("Error setting SDL_HINT_JOYSTICK_ALLOW_BACKGROUND_EVENTS\n");
+	}
 
 	// Initialize the configuration system
 	g_config = InitConfig();
diff --git a/src/drivers/sdl/sdl.cpp b/src/drivers/sdl/sdl.cpp
index 21dfba68..59d2e6c1 100644
--- a/src/drivers/sdl/sdl.cpp
+++ b/src/drivers/sdl/sdl.cpp
@@ -355,6 +355,7 @@ FCEUD_Update(uint8 *XBuf,
 			 int32 *Buffer,
 			 int Count)
 {
+	int blitDone = 0;
 	extern int FCEUDnetplay;
 
 	#ifdef CREATE_AVI
@@ -381,8 +382,8 @@ FCEUD_Update(uint8 *XBuf,
 		if (!mutecapture)
 		  if(Count > 0 && Buffer) WriteSound(Buffer,Count);   
 	  }
-	  if(inited & 2)
-		FCEUD_UpdateInput();
+	//  if(inited & 2)
+	//	FCEUD_UpdateInput();
 	  if(XBuf && (inited & 4)) BlitScreen(XBuf);
 	  
 	  //SpeedThrottle();
@@ -414,7 +415,9 @@ FCEUD_Update(uint8 *XBuf,
 		// don't underflow when scaling fps
 		if(g_fpsScale>1.0 || ((tmpcan < Count*0.90) && !uflow)) {
 			if(XBuf && (inited&4) && !(NoWaiting & 2))
-				BlitScreen(XBuf);
+			{
+				BlitScreen(XBuf); blitDone = 1;
+			}
 			Buffer+=can;
 			Count-=can;
 			if(Count) {
@@ -449,24 +452,23 @@ FCEUD_Update(uint8 *XBuf,
 		}
 
 	} else {
-		if(!NoWaiting && (!(eoptions&EO_NOTHROTTLE) || FCEUI_EmulationPaused()))
-		while (SpeedThrottle())
+		//if(!NoWaiting && (!(eoptions&EO_NOTHROTTLE) || FCEUI_EmulationPaused()))
+		//while (SpeedThrottle())
+		//{
+		//	FCEUD_UpdateInput();
+		//}
+		if (XBuf && (inited&4)) 
 		{
-			FCEUD_UpdateInput();
-		}
-		if(XBuf && (inited&4)) {
-			BlitScreen(XBuf);
+			BlitScreen(XBuf); blitDone = 1;
+		}
+	}
+	if ( !blitDone )
+	{
+		if (XBuf && (inited&4)) 
+		{
+			BlitScreen(XBuf); blitDone = 1;
 		}
 	}
-	FCEUD_UpdateInput();
-	//if(!Count && !NoWaiting && !(eoptions&EO_NOTHROTTLE))
-	// SpeedThrottle();
-	//if(XBuf && (inited&4))
-	//{
-	// BlitScreen(XBuf);
-	//}
-	//if(Count)
-	// WriteSound(Buffer,Count,NoWaiting);
 	//FCEUD_UpdateInput();
 }
 
@@ -564,6 +566,10 @@ int main(int argc, char *argv[])
 		printf("Could not initialize SDL: %s.\n", SDL_GetError());
 		return(-1);
 	}
+	if ( SDL_SetHint( SDL_HINT_JOYSTICK_ALLOW_BACKGROUND_EVENTS, "1" ) == SDL_FALSE )
+	{
+		printf("Error setting SDL_HINT_JOYSTICK_ALLOW_BACKGROUND_EVENTS\n");
+	}
 
 //#ifdef OPENGL
 //	SDL_GL_LoadLibrary(0);
@@ -914,8 +920,9 @@ int main(int argc, char *argv[])
 			}
 			else
 			{
-				SDL_Delay(1);
+				SDL_Delay(10);
 			}
+			FCEUD_UpdateInput();
 
 			while(gtk_events_pending())
 			{