From a769783d5d28ebf3fa3ac372fa11f11bb06cd2b0 Mon Sep 17 00:00:00 2001
From: prefect <nicolai@wildfiregames.com>
Date: Wed, 28 Sep 2005 23:57:55 +0000
Subject: [PATCH] Fix scroll wheel zooming on Linux.

Refactored HandleEvent into CGameView.

This was SVN commit r2800.
---
 source/graphics/GameView.cpp | 51 ++++++++++++++++++++++--------------
 source/graphics/GameView.h   |  5 ++++
 source/main.cpp              |  2 +-
 3 files changed, 37 insertions(+), 21 deletions(-)

diff --git a/source/graphics/GameView.cpp b/source/graphics/GameView.cpp
index 51df2e677c..91048c09b5 100755
--- a/source/graphics/GameView.cpp
+++ b/source/graphics/GameView.cpp
@@ -57,7 +57,8 @@ CGameView::CGameView(CGame *pGame):
 	m_ViewZoomSmoothness(0.02f),
 	m_ViewSnapSmoothness(0.02f),
 	m_CameraPivot(),
-	m_CameraDelta()
+	m_CameraDelta(),
+	m_ZoomDelta(0)
 {
 	SViewPort vp;
 	vp.m_X=0;
@@ -527,24 +528,18 @@ void CGameView::Update(float DeltaTime)
 	}
 
 	// Smoothed zooming (move a certain percentage towards the desired zoom distance every frame)
-
-	static float zoom_delta = 0.0f;
-
-	if( hotkeys[HOTKEY_CAMERA_ZOOM_WHEEL_IN] )
-		zoom_delta += m_ViewZoomSensitivityWheel;
-	else if( hotkeys[HOTKEY_CAMERA_ZOOM_WHEEL_OUT] )
-		zoom_delta -= m_ViewZoomSensitivityWheel;
+	// Note that scroll wheel zooming is event-based and handled in game_view_handler
 
 	if( hotkeys[HOTKEY_CAMERA_ZOOM_IN] )
-		zoom_delta += m_ViewZoomSensitivity*DeltaTime;
+		m_ZoomDelta += m_ViewZoomSensitivity*DeltaTime;
 	else if( hotkeys[HOTKEY_CAMERA_ZOOM_OUT] )
-		zoom_delta -= m_ViewZoomSensitivity*DeltaTime;
+		m_ZoomDelta -= m_ViewZoomSensitivity*DeltaTime;
 
-	if (fabsf(zoom_delta) > 0.1f) // use a fairly high limit to avoid nasty flickering when zooming
+	if (fabsf(m_ZoomDelta) > 0.1f) // use a fairly high limit to avoid nasty flickering when zooming
 	{
 		float zoom_proportion = powf(m_ViewZoomSmoothness, DeltaTime);
-		CameraLock(forwards * (zoom_delta * (1.0f-zoom_proportion)), false);
-		zoom_delta *= zoom_proportion;
+		CameraLock(forwards * (m_ZoomDelta * (1.0f-zoom_proportion)), false);
+		m_ZoomDelta *= zoom_proportion;
 	}
 
 
@@ -700,6 +695,11 @@ int game_view_handler(const SDL_Event* ev)
 
 	CGameView *pView=g_Game->GetView();
 
+	return pView->HandleEvent(ev);
+}
+
+int CGameView::HandleEvent(const SDL_Event* ev)
+{
 	switch(ev->type)
 	{
 
@@ -715,15 +715,26 @@ int game_view_handler(const SDL_Event* ev)
 			return( EV_HANDLED );
 
 		case HOTKEY_CAMERA_RESET_ORIGIN:
-			pView->ResetCamera();
+			ResetCamera();
 			return( EV_HANDLED );
 
 		case HOTKEY_CAMERA_RESET:
-			pView->ResetCameraOrientation();
+			ResetCameraOrientation();
 			return( EV_HANDLED );
 
 		case HOTKEY_CAMERA_ROTATE_ABOUT_TARGET:
-			pView->RotateAboutTarget();
+			RotateAboutTarget();
+			return( EV_HANDLED );
+
+		// Mouse wheel must be treated using events instead of polling,
+		// because SDL auto-generates a sequence of mousedown/mouseup events automatically 
+		// on Linux, and we never get to see the "down" state inside Update().
+		case HOTKEY_CAMERA_ZOOM_WHEEL_IN:
+			m_ZoomDelta += m_ViewZoomSensitivityWheel;
+			return( EV_HANDLED );
+				
+		case HOTKEY_CAMERA_ZOOM_WHEEL_OUT:
+			m_ZoomDelta -= m_ViewZoomSensitivityWheel;
 			return( EV_HANDLED );
 
 		default:
@@ -736,21 +747,21 @@ int game_view_handler(const SDL_Event* ev)
 				if( hotkeys[HOTKEY_CAMERA_BOOKMARK_SAVE] )
 				{
 					// Attempt to track the ground we're looking at
-					cameraBookmarks[id] = pView->GetCamera()->GetFocus();
+					cameraBookmarks[id] = GetCamera()->GetFocus();
 					bookmarkInUse[id] = true;
 				}
 				else if( hotkeys[HOTKEY_CAMERA_BOOKMARK_SNAP] )
 				{
 					if( bookmarkInUse[id] && ( currentBookmark == -1 ) )
 					{
-						pView->PushCameraTarget( cameraBookmarks[id] );
+						PushCameraTarget( cameraBookmarks[id] );
 						currentBookmark = id;
 					}
 				}
 				else
 				{
 					if( bookmarkInUse[id] )
-						pView->SetCameraTarget( cameraBookmarks[id] );
+						SetCameraTarget( cameraBookmarks[id] );
 				}
 				return( EV_HANDLED );
 			}
@@ -760,7 +771,7 @@ int game_view_handler(const SDL_Event* ev)
 		{
 			case HOTKEY_CAMERA_BOOKMARK_SNAP:
 				if( currentBookmark != -1 )
-					pView->PopCameraTarget();
+					PopCameraTarget();
 				currentBookmark = -1;
 				break;
 			default:
diff --git a/source/graphics/GameView.h b/source/graphics/GameView.h
index d6c69e1505..66ae815854 100755
--- a/source/graphics/GameView.h
+++ b/source/graphics/GameView.h
@@ -48,6 +48,9 @@ class CGameView: public CJSObject<CGameView>
 	//float m_CameraZoom;
 	std::vector<CVector3D> m_CameraTargets;
 
+	// Accumulate zooming changes across frames for smoothness
+	float m_ZoomDelta;
+	
 	// RenderTerrain: iterate through all terrain patches and submit all patches
 	// in viewing frustum to the renderer, for terrain painting
 	void RenderTerrain(CTerrain *pTerrain);
@@ -92,6 +95,8 @@ public:
 	// Render: Render the World
 	void Render();
 
+	int HandleEvent(const SDL_Event* ev);
+
 	//Keep the camera in between boundaries/smooth camera scrolling/translating
 	//Should call this whenever moving (translating) the camera
 	void CameraLock(CVector3D Trans, bool smooth=true);
diff --git a/source/main.cpp b/source/main.cpp
index 6df587cd4b..24bb7dfdc6 100755
--- a/source/main.cpp
+++ b/source/main.cpp
@@ -53,7 +53,7 @@ void kill_mainloop();
 //
 
 bool keys[SDLK_LAST];
-bool mouse_buttons[5];	// CAN REMOVE AFTER MOVING RESET TO WSDL
+bool mouse_buttons[6];	// CAN REMOVE AFTER MOVING RESET TO WSDL
 
 bool g_active = true;
 int g_mouse_x = 50, g_mouse_y = 50;