fix #5956

rts/Game/UI/MouseHandler.cpp

@@ -76,7 +76,7 @@ static CInputReceiver*& activeReceiver = CInputReceiver::GetActiveReceiverRef();
 
 CMouseHandler::CMouseHandler()
 {
-	const int2 mousepos = IMouseInput::GetInstance()->GetPos();
+	const int2 mousepos = mouseInput->GetPos();
 
 	lastx = mousepos.x;
 	lasty = mousepos.y;
@@ -111,11 +111,15 @@ CMouseHandler::~CMouseHandler()
 void CMouseHandler::InitStatic()
 {
 	assert(mouse == nullptr);
+	assert(mouseInput == nullptr);
+
+	mouseInput = IMouseInput::GetInstance();
 	mouse = new CMouseHandler();
 }
 
 void CMouseHandler::KillStatic()
 {
+	IMouseInput::FreeInstance(mouseInput);
 	spring::SafeDelete(mouse);
 }
 
@@ -615,7 +619,7 @@ void CMouseHandler::WarpMouse(int x, int y)
 	lastx = x + globalRendering->viewPosX;
 	lasty = y + globalRendering->viewPosY;
 
-	mouseInput->SetPos(int2(lastx, lasty));
+	mouseInput->SetWarpPos({lastx, lasty});
 }
 
 
@@ -627,25 +631,34 @@ void CMouseHandler::ShowMouse()
 	hide = false;
 	cursorText = "none"; // force hardware cursor rebinding (else we have standard b&w cursor)
 
-	// don't use SDL_ShowCursor here, it would cause a flicker with hwCursor
+	SDL_SetRelativeMouseMode(SDL_FALSE);
+
+	// don't use SDL_ShowCursor here since it would cause flickering with hwCursor
 	// (by switching between default cursor and later the real one, e.g. `attack`)
 	// instead update state and cursor at the same time
 	if (hardwareCursor) {
 		hwHide = true;
 	} else {
 		SDL_ShowCursor(SDL_DISABLE);
 	}
-}
 
+	mouseInput->SetWarpPos(globalRendering->GetScreenCenter());
+}
 
 void CMouseHandler::HideMouse()
 {
 	if (hide)
 		return;
 
+	hide = true;
 	hwHide = true;
+
 	SDL_ShowCursor(SDL_DISABLE);
-	mouseInput->SetWMMouseCursor(nullptr);
+	// signal that we are only interested in relative motion events when MMB-scrolling
+	// this way the mouse position will never change so it is also unnecessary to call
+	// SDL_WarpMouseInWindow with associated warts (i.e. filtering of motion events by
+	// hand...); technically supercedes SDL_ShowCursor as well
+	SDL_SetRelativeMouseMode(SDL_TRUE);
 
 	const int2 screenCenter = globalRendering->GetScreenCenter();
 
@@ -654,8 +667,8 @@ void CMouseHandler::HideMouse()
 	lastx = screenCenter.x;
 	lasty = screenCenter.y;
 
+	mouseInput->SetWMMouseCursor(nullptr);
 	mouseInput->SetPos(screenCenter);
-	hide = true;
 }
 
 

rts/System/Input/MouseInput.cpp

@@ -22,15 +22,15 @@
 #include "MouseInput.h"
 #include "InputHandler.h"
 
-#include "Game/GlobalUnsynced.h"
 #include "Game/UI/MouseHandler.h"
 #include "Rendering/GlobalRendering.h"
-#include "Rendering/GL/FBO.h"
 #include "System/MainDefines.h"
 #include "System/SafeUtil.h"
 
 #include <functional>
+
 #include <SDL_events.h>
+#include <SDL_hints.h>
 #include <SDL_syswm.h>
 
 
@@ -94,12 +94,12 @@ bool IMouseInput::HandleSDLMouseEvent(const SDL_Event& event)
 
 //////////////////////////////////////////////////////////////////////
 
-#if defined(WIN32) && !defined (HEADLESS)
+#if defined(WIN32) && !defined(HEADLESS)
 
 class CWin32MouseInput : public IMouseInput
 {
 public:
-	static CWin32MouseInput *inst;
+	static CWin32MouseInput* inst;
 
 	LONG_PTR sdl_wndproc;
 	HWND wnd;
@@ -108,11 +108,11 @@ class CWin32MouseInput : public IMouseInput
 	static LRESULT CALLBACK SpringWndProc(HWND wnd, UINT msg, WPARAM wParam, LPARAM lParam)
 	{
 		switch (msg) {
-			case WM_SETCURSOR:
-			{
-				if (inst->hCursor!=NULL) {
-					Uint16 hittest = LOWORD(lParam);
-					if ( hittest == HTCLIENT ) {
+			case WM_SETCURSOR: {
+				if (inst->hCursor != nullptr) {
+					const Uint16 hittest = LOWORD(lParam);
+
+					if (hittest == HTCLIENT) {
 						SetCursor(inst->hCursor);
 						return TRUE;
 					}
@@ -137,9 +137,10 @@ class CWin32MouseInput : public IMouseInput
 		wnd = info.info.win.window;
 
 		LONG_PTR cur_wndproc = GetWindowLongPtr(wnd, GWLP_WNDPROC);
+
 		if (cur_wndproc != (LONG_PTR)SpringWndProc) {
 			sdl_wndproc = GetWindowLongPtr(wnd, GWLP_WNDPROC);
-			SetWindowLongPtr(wnd,GWLP_WNDPROC,(LONG_PTR)SpringWndProc);
+			SetWindowLongPtr(wnd,GWLP_WNDPROC, (LONG_PTR)SpringWndProc);
 		}
 	}
 
@@ -149,42 +150,79 @@ class CWin32MouseInput : public IMouseInput
 		hCursor = nullptr;
 		sdl_wndproc = 0;
 		wnd = 0;
+
 		InstallWndCallback();
+		// Windows 10 FCU (Fall Creators Update) causes spurious SDL_MOUSEMOTION
+		// events to be generated with SDL_HINT_MOUSE_RELATIVE_MODE_WARP enabled
+		//
+		// while Spring did not previously set this hint and SDL defaults to raw
+		// input, the update also affects MMB scrolling via SDL_WarpMouseInWindow
+		// (our ancient manually implemented method of achieving relative motion)
+		//
+		// win32 SDL hides these events in 2.0.8 only if mouse->relative_mode_warp
+		// (which configures relative mouse mode to *internally* use mouse warping
+		// instead of raw input and gets toggled by SDL_SetRelativeMouseMode based
+		// on the hint given here); the alternative to RMW would be to *duplicate*
+		// the SDL patch in SetPosSDL
+		SDL_SetHint(SDL_HINT_MOUSE_RELATIVE_MODE_WARP, "1");
 	}
 	~CWin32MouseInput()
 	{
 		// reinstall the SDL window proc
 		SetWindowLongPtr(wnd, GWLP_WNDPROC, sdl_wndproc);
+		SDL_SetHint(SDL_HINT_MOUSE_RELATIVE_MODE_WARP, "0");
 	}
 };
+
 CWin32MouseInput* CWin32MouseInput::inst = nullptr;
+
+
+static uint8_t mouseInputMem[sizeof(CWin32MouseInput)];
+#else
+static uint8_t mouseInputMem[sizeof(IMouseInput)];
 #endif
 
 
+
+#if 1
 static SDL_Event events[100];
+#endif
 
-void IMouseInput::SetPos(int2 pos)
+bool IMouseInput::SetPos(int2 pos)
 {
 	if (!globalRendering->active)
-		return;
+		return false;
 
 	// calling SDL_WarpMouse at 300fps eats ~5% cpu usage, so only update when needed
 	if (pos.x == mousepos.x && pos.y == mousepos.y)
-		return;
+		return false;
 
-	mousepos = pos;
+	return (mousepos = pos, true);
+}
 
+bool IMouseInput::WarpPos(int2 pos)
+{
 	SDL_WarpMouseInWindow(globalRendering->GetWindow(0), pos.x, pos.y);
 
 	// SDL_WarpMouse generates SDL_MOUSEMOTION events
 	// in `middle click scrolling` those SDL generated ones would point into
 	// the opposite direction the user moved the mouse, and so events would
-	// cancel each other -> camera wouldn't move at all
-	// so we need to catch those SDL generated events and delete them
-
-	// delete all SDL_MOUSEMOTION in the queue
+	// cancel each other -> camera wouldn't move at all or jitter
+	// need to catch the SDL generated events and delete them from its queue
+	//
+	// NOTE [2018]:
+	//   the above comment dates back to 2010, but also describes the recent
+	//   Windows 10 FCU bug with relative mode warping which similarly relies
+	//   on WMIW
+	#if 1
 	SDL_PumpEvents();
 	SDL_PeepEvents(&events[0], sizeof(events) / sizeof(events[0]), SDL_GETEVENT, SDL_MOUSEMOTION, SDL_MOUSEMOTION);
+	#else
+	// should be equivalent, but for some reason is not
+	SDL_FlushEvent(SDL_MOUSEMOTION);
+	#endif
+
+	return true;
 }
 
 
@@ -193,14 +231,18 @@ IMouseInput* IMouseInput::GetInstance()
 {
 	if (mouseInput == nullptr) {
 #if defined(WIN32) && !defined(HEADLESS)
-		mouseInput = new CWin32MouseInput;
+		mouseInput = new (mouseInputMem) CWin32MouseInput();
 #else
-		mouseInput = new IMouseInput;
+		mouseInput = new (mouseInputMem) IMouseInput();
 #endif
 	}
+
 	return mouseInput;
 }
 
 void IMouseInput::FreeInstance(IMouseInput* mouseInp) {
-	spring::SafeDelete(mouseInp);
+	assert(mouseInp == &mouseInputMem[0]);
+	spring::SafeDestruct(mouseInp);
+	memset(mouseInputMem, 0, sizeof(mouseInputMem));
 }
+

rts/System/Input/MouseInput.h

@@ -20,8 +20,11 @@ class IMouseInput
 
 	virtual void InstallWndCallback() {}
 
-	virtual int2 GetPos() { return mousepos; }
-	void SetPos(int2 pos);
+	int2 GetPos() const { return mousepos; }
+
+	bool SetPos(int2 pos);
+	bool WarpPos(int2 pos);
+	bool SetWarpPos(int2 pos) { return (SetPos(pos) && WarpPos(pos)); }
 
 	bool HandleSDLMouseEvent(const SDL_Event& event);
 

rts/System/SpringApp.cpp

@@ -259,7 +259,6 @@ bool SpringApp::Init()
 	CInfoConsole::InitStatic();
 	CMouseHandler::InitStatic();
 
-	mouseInput = IMouseInput::GetInstance();
 	input.AddHandler(std::bind(&SpringApp::MainEventHandler, this, std::placeholders::_1));
 
 	// Global structures
@@ -908,7 +907,6 @@ void SpringApp::Kill(bool fromRun)
 
 	CInfoConsole::KillStatic();
 	CMouseHandler::KillStatic();
-	IMouseInput::FreeInstance(mouseInput);
 
 	LOG("[SpringApp::%s][6]", __func__);
 	gs->Kill();