Minor update for example 19.MouseAndJoystick.

Don't move the mouse anymore when the mouse hasn't moved.
This was sometimes confusing because events are only caught inside the window (at least on Windows),
which lead to the node moving seemingly randomly when the mouse was outside.
Also added a few more comments to mention CursorControl as an alternative.


git-svn-id: svn://svn.code.sf.net/p/irrlicht/code/trunk@6308 dfc29bdd-3216-0410-991c-e03cc46cb475

examples/19.MouseAndJoystick/main.cpp

@@ -8,8 +8,6 @@ devices.
 */
 
 #ifdef _MSC_VER
-// We'll define this to stop MSVC complaining about sprintf().
-#define _CRT_SECURE_NO_WARNINGS
 #pragma comment(lib, "Irrlicht.lib")
 #endif
 
@@ -19,8 +17,21 @@ devices.
 using namespace irr;
 
 /*
-Just as we did in example 04.Movement, we'll store the latest state of the
+Just as we did in example 04.Movement with keys, we'll store the latest state of the
 mouse and the first joystick, updating them as we receive events.
+
+Note that instead of working with events we could work with CursorControl, aka
+device->getCursorControl(), to get the current mouse state.
+With events you get every mouse movement since the last device->run(), 
+while CursorControl will always return the current state at the moment you check it.
+CursorControl will be able to get cursor positions even if the mouse is outside the 
+active Window, while the behavior of mouse-events for this is a bit system dependent 
+and also can be influenced by system calls for mouse-grabbing.
+Events tend to work on more devices (especially mobile devices) where CursorControl might
+not be available. Also on some systems (X11) checking the mouse position with CursorControl
+can be rather slow compared to events.
+Often it depends a bit on the type of game which solution is preferable, just be aware
+that you have some choice for this.
 */
 class MyEventReceiver : public IEventReceiver
 {
@@ -30,7 +41,8 @@ public:
 	{
 		core::position2di Position;
 		bool LeftButtonDown;
-		SMouseState() : LeftButtonDown(false) { }
+		bool WasMouseMoved;
+		SMouseState() : LeftButtonDown(false), WasMouseMoved(false) { }
 	} MouseState;
 
 	// This is the one method that we have to implement
@@ -52,6 +64,7 @@ public:
 			case EMIE_MOUSE_MOVED:
 				MouseState.Position.X = event.MouseInput.X;
 				MouseState.Position.Y = event.MouseInput.Y;
+				MouseState.WasMouseMoved = true;
 				break;
 
 			default:
@@ -63,7 +76,6 @@ public:
 		// The state of each connected joystick is sent to us
 		// once every run() of the Irrlicht device.  Store the
 		// state of the first joystick, ignoring other joysticks.
-		// This is currently only supported on Windows and Linux.
 		if (event.EventType == irr::EET_JOYSTICK_INPUT_EVENT
 			&& event.JoystickEvent.Joystick == 0)
 		{
@@ -83,9 +95,9 @@ public:
 		return MouseState;
 	}
 
-
+	void ResetMouseMoved()
-	MyEventReceiver()
 	{
+		MouseState.WasMouseMoved = false;
 	}
 
 private:
@@ -94,11 +106,9 @@ private:
 
 
 /*
-The event receiver for keeping the pressed keys is ready, the actual responses
+The event receiver for remembering the events is ready, the actual responses
 will be made inside the render loop, right before drawing the scene. So lets
-just create an irr::IrrlichtDevice and the scene node we want to move. We also
+just create an irr::IrrlichtDevice and the scene node we want to move.
-create some other additional scene nodes, to show that there are also some
-different possibilities to move and animate scene nodes.
 */
 int main()
 {
@@ -117,6 +127,11 @@ int main()
 		return 1; // could not create selected driver.
 
 
+	/*
+		Joysticks have to be activated to generate events.
+		So lets's do that and also print out some info to the console
+		about all the joysticks we found and can use.
+	*/
 	core::array<SJoystickInfo> joystickInfo;
 	if(device->activateJoysticks(joystickInfo))
 	{
@@ -153,6 +168,7 @@ int main()
 		std::cout << "Joystick support is not enabled." << std::endl;
 	}
 
+	// Set some window caption text
 	core::stringw tmp = L"Irrlicht Joystick Example (";
 	tmp += joystickInfo.size();
 	tmp += " joysticks)";
@@ -179,20 +195,25 @@ int main()
 	camera->setPosition(core::vector3df(0, 0, -10));
 
 	// As in example 04, we'll use framerate independent movement.
-	u32 then = device->getTimer()->getTime();
+	u32 then = device->getTimer()->getRealTime();
 	const f32 MOVEMENT_SPEED = 5.f;
+	bool followMouse = true;
+
+	// Ignore all events which happened until now.
+	// Like mouse events triggered while we chose our driver.
+	device->clearSystemMessages();
 
 	while(device->run())
 	{
 		// Work out a frame delta time.
-		const u32 now = device->getTimer()->getTime();
+		const u32 now = device->getTimer()->getRealTime();
 		const f32 frameDeltaTime = (f32)(now - then) / 1000.f; // Time in seconds
 		then = now;
 
 		bool movedWithJoystick = false;
 		core::vector3df nodePosition = node->getPosition();
 
-		if(joystickInfo.size() > 0)
+		if(joystickInfo.size() > 0)	// if we have at least one joystick
 		{
 			f32 moveHorizontal = 0.f; // Range is -1.f for full left to +1.f for full right
 			f32 moveVertical = 0.f; // -1.f for full down to +1.f for full up.
@@ -237,11 +258,14 @@ int main()
 				nodePosition.X += MOVEMENT_SPEED * frameDeltaTime * moveHorizontal;
 				nodePosition.Y += MOVEMENT_SPEED * frameDeltaTime * moveVertical;
 				movedWithJoystick = true;
+
+				// We only go back to following mouse when it moves again
+				receiver.ResetMouseMoved();
 			}
 		}
 
 		// If the arrow node isn't being moved with the joystick, then have it follow the mouse cursor.
-		if(!movedWithJoystick)
+		if (!movedWithJoystick && receiver.GetMouseState().WasMouseMoved)
 		{
 			// Create a ray through the mouse cursor.
 			core::line3df ray = smgr->getSceneCollisionManager()->getRayFromScreenCoordinates(
@@ -257,11 +281,15 @@ int main()
 				const f32 availableMovement = MOVEMENT_SPEED * frameDeltaTime;
 
 				if(toMousePosition.getLength() <= availableMovement)
+				{
 					nodePosition = mousePosition; // Jump to the final position
+				}
 				else
+				{
 					nodePosition += toMousePosition.normalize() * availableMovement; // Move towards it
 				}
 			}
+		}
 
 		node->setPosition(nodePosition);