Codechange: [Video] make the prototype of PollEvent() the same for all drivers

Additionally, call it from the draw-tick.

src/video/allegro_v.cpp

@@ -329,7 +329,7 @@ static uint32 ConvertAllegroKeyIntoMy(WChar *character)
 static const uint LEFT_BUTTON  = 0;
 static const uint RIGHT_BUTTON = 1;
 
-static void PollEvent()
+bool VideoDriver_Allegro::PollEvent()
 {
 	poll_mouse();
 
@@ -403,6 +403,8 @@ static void PollEvent()
 		uint keycode = ConvertAllegroKeyIntoMy(&character);
 		HandleKeypress(keycode, character);
 	}
+
+	return false;
 }
 
 /**
@@ -482,7 +484,6 @@ void VideoDriver_Allegro::MainLoop()
 	for (;;) {
 		InteractiveRandom(); // randomness
 
-		PollEvent();
 		if (_exit_game) return;
 
 		if (this->Tick()) {

src/video/allegro_v.h

@@ -37,6 +37,7 @@ protected:
 	void InputLoop() override;
 	void Paint() override;
 	void CheckPaletteAnim() override;
+	bool PollEvent() override;
 };
 
 /** Factory for the allegro video driver. */

src/video/cocoa/cocoa_v.h

@@ -62,6 +62,7 @@ protected:
 	void InputLoop() override;
 	bool LockVideoBuffer() override;
 	void UnlockVideoBuffer() override;
+	bool PollEvent() override;
 
 	void GameSizeChanged();
 
@@ -79,8 +80,6 @@ protected:
 	virtual void ReleaseVideoPointer() {}
 
 private:
-	bool PollEvent();
-
 	bool IsFullscreen();
 };
 

src/video/cocoa/cocoa_v.mm

@@ -440,8 +440,6 @@ void VideoDriver_Cocoa::GameLoop()
 
 			InteractiveRandom(); // randomness
 
-			while (this->PollEvent()) {}
-
 			if (_exit_game) {
 				/* Restore saved resolution if in fullscreen mode. */
 				if (this->IsFullscreen()) _cur_resolution = this->orig_res;

src/video/sdl2_v.cpp

@@ -370,11 +370,11 @@ static uint ConvertSdlKeycodeIntoMy(SDL_Keycode kc)
 	return key;
 }
 
-int VideoDriver_SDL_Base::PollEvent()
+bool VideoDriver_SDL_Base::PollEvent()
 {
 	SDL_Event ev;
 
-	if (!SDL_PollEvent(&ev)) return -2;
+	if (!SDL_PollEvent(&ev)) return false;
 
 	switch (ev.type) {
 		case SDL_MOUSEMOTION:
@@ -516,7 +516,8 @@ int VideoDriver_SDL_Base::PollEvent()
 			break;
 		}
 	}
-	return -1;
+
+	return true;
 }
 
 static const char *InitializeSDL()
@@ -629,7 +630,6 @@ void VideoDriver_SDL_Base::LoopOnce()
 {
 	InteractiveRandom(); // randomness
 
-	while (PollEvent() == -1) {}
 	if (_exit_game) {
 #ifdef __EMSCRIPTEN__
 		/* Emscripten is event-driven, and as such the main loop is inside

src/video/sdl2_v.h

@@ -60,6 +60,7 @@ protected:
 	bool LockVideoBuffer() override;
 	void UnlockVideoBuffer() override;
 	void CheckPaletteAnim() override;
+	bool PollEvent() override;
 
 	/** Indicate to the driver the client-side might have changed. */
 	void ClientSizeChanged(int w, int h, bool force);
@@ -74,7 +75,6 @@ protected:
 	virtual bool CreateMainWindow(uint w, uint h, uint flags = 0);
 
 private:
-	int PollEvent();
 	void LoopOnce();
 	void MainLoopCleanup();
 	bool CreateMainSurface(uint w, uint h, bool resize);

src/video/sdl_v.cpp

@@ -507,11 +507,11 @@ static uint ConvertSdlKeyIntoMy(SDL_keysym *sym, WChar *character)
 	return key;
 }
 
-int VideoDriver_SDL::PollEvent()
+bool VideoDriver_SDL::PollEvent()
 {
 	SDL_Event ev;
 
-	if (!SDL_PollEvent(&ev)) return -2;
+	if (!SDL_PollEvent(&ev)) return false;
 
 	switch (ev.type) {
 		case SDL_MOUSEMOTION:
@@ -598,7 +598,8 @@ int VideoDriver_SDL::PollEvent()
 			break;
 		}
 	}
-	return -1;
+
+	return true;
 }
 
 const char *VideoDriver_SDL::Start(const StringList &parm)
@@ -719,7 +720,6 @@ void VideoDriver_SDL::MainLoop()
 	for (;;) {
 		InteractiveRandom(); // randomness
 
-		while (PollEvent() == -1) {}
 		if (_exit_game) break;
 
 		if (this->Tick()) {

src/video/sdl_v.h

@@ -43,12 +43,12 @@ protected:
 	void UnlockVideoBuffer() override;
 	void Paint() override;
 	void PaintThread() override;
-	void CheckPaletteAnim();
+	void CheckPaletteAnim() override;
+	bool PollEvent() override;
 
 private:
 	std::unique_lock<std::recursive_mutex> draw_lock;
 
-	int PollEvent();
 	bool CreateMainSurface(uint w, uint h);
 	void SetupKeyboard();
 

src/video/video_driver.cpp

@@ -55,6 +55,7 @@ bool VideoDriver::Tick()
 		/* Avoid next_draw_tick getting behind more and more if it cannot keep up. */
 		if (this->next_draw_tick < cur_ticks - ALLOWED_DRIFT * this->GetDrawInterval()) this->next_draw_tick = cur_ticks;
 
+		while (this->PollEvent()) {}
 		this->InputLoop();
 		::InputLoop();
 		UpdateWindows();

src/video/video_driver.hpp

@@ -249,6 +249,12 @@ protected:
 	 */
 	virtual void CheckPaletteAnim() {}
 
+	/**
+	 * Process a single system event.
+	 * @returns False if there are no more events to process.
+	 */
+	virtual bool PollEvent() { return false; };
+
 	/**
 	 * Run the game for a single tick, processing boththe game-tick and draw-tick.
 	 * @returns True if the driver should redraw the screen.

src/video/win32_v.cpp

@@ -857,10 +857,21 @@ void VideoDriver_Win32Base::InputLoop()
 	if (old_ctrl_pressed != _ctrl_pressed) HandleCtrlChanged();
 }
 
-void VideoDriver_Win32Base::MainLoop()
+bool VideoDriver_Win32Base::PollEvent()
 {
 	MSG mesg;
 
+	if (!PeekMessage(&mesg, nullptr, 0, 0, PM_REMOVE)) return false;
+
+	/* Convert key messages to char messages if we want text input. */
+	if (EditBoxInGlobalFocus()) TranslateMessage(&mesg);
+	DispatchMessage(&mesg);
+
+	return true;
+}
+
+void VideoDriver_Win32Base::MainLoop()
+{
 	std::thread draw_thread;
 
 	if (this->draw_threaded) {
@@ -898,11 +909,6 @@ void VideoDriver_Win32Base::MainLoop()
 	for (;;) {
 		InteractiveRandom(); // randomness
 
-		while (PeekMessage(&mesg, nullptr, 0, 0, PM_REMOVE)) {
-			/* Convert key messages to char messages if we want text input. */
-			if (EditBoxInGlobalFocus()) TranslateMessage(&mesg);
-			DispatchMessage(&mesg);
-		}
 		if (_exit_game) break;
 
 		/* Flush GDI buffer to ensure we don't conflict with the drawing thread. */

src/video/win32_v.h

@@ -60,6 +60,7 @@ protected:
 	bool LockVideoBuffer() override;
 	void UnlockVideoBuffer() override;
 	void CheckPaletteAnim() override;
+	bool PollEvent() override;
 
 	void Initialize();
 	bool MakeWindow(bool full_screen);