/* Copyright (C) 2011 Wildfire Games.
 * This file is part of 0 A.D.
 *
 * 0 A.D. is free software: you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation, either version 2 of the License, or
 * (at your option) any later version.
 *
 * 0 A.D. is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with 0 A.D.  If not, see <http://www.gnu.org/licenses/>.
 */

#include "precompiled.h"

#include "GameView.h"

#include "graphics/Camera.h"
#include "graphics/CinemaTrack.h"
#include "graphics/ColladaManager.h"
#include "graphics/HFTracer.h"
#include "graphics/LightEnv.h"
#include "graphics/LOSTexture.h"
#include "graphics/Model.h"
#include "graphics/ObjectManager.h"
#include "graphics/Patch.h"
#include "graphics/SkeletonAnimManager.h"
#include "graphics/Terrain.h"
#include "graphics/TerrainTextureManager.h"
#include "graphics/Unit.h"
#include "graphics/UnitManager.h"
#include "lib/input.h"
#include "lib/timer.h"
#include "maths/Bound.h"
#include "maths/MathUtil.h"
#include "maths/Matrix3D.h"
#include "maths/Quaternion.h"
#include "ps/ConfigDB.h"
#include "ps/Game.h"
#include "ps/Globals.h"
#include "ps/Hotkey.h"
#include "ps/Joystick.h"
#include "ps/Loader.h"
#include "ps/LoaderThunks.h"
#include "ps/Profile.h"
#include "ps/Pyrogenesis.h"
#include "ps/World.h"
#include "renderer/Renderer.h"
#include "renderer/WaterManager.h"
#include "scripting/ScriptableObject.h"
#include "simulation/LOSManager.h"
#include "simulation2/Simulation2.h"
#include "simulation2/components/ICmpPosition.h"
#include "simulation2/components/ICmpRangeManager.h"

extern int g_xres, g_yres;

const float CGameView::defaultFOV = DEGTORAD(20.f);
const float CGameView::defaultNear = 16.f;
const float CGameView::defaultFar = 4096.f;
const float CGameView::defaultCullFOV = CGameView::defaultFOV + DEGTORAD(6.0f);	//add 6 degrees to the default FOV for use with the culling frustum

// Maximum distance outside the edge of the map that the camera's
// focus point can be moved
static const float CAMERA_EDGE_MARGIN = 2.0f*CELL_SIZE;

/**
 * A value with exponential decay towards the target value.
 */
class CSmoothedValue
{
public:
	CSmoothedValue(float value, float smoothness, float minDelta)
		: m_Target(value), m_Current(value), m_Smoothness(smoothness), m_MinDelta(minDelta)
	{
	}

	float GetSmoothedValue()
	{
		return m_Current;
	}

	void SetValueSmoothly(float value)
	{
		m_Target = value;
	}

	void AddSmoothly(float value)
	{
		m_Target += value;
	}

	void Add(float value)
	{
		m_Target += value;
		m_Current += value;
	}

	float GetValue()
	{
		return m_Target;
	}

	void SetValue(float value)
	{
		m_Target = value;
		m_Current = value;
	}

	float Update(float time)
	{
		if (fabs(m_Target - m_Current) < m_MinDelta)
			return 0.0f;

		double p = pow((double)m_Smoothness, 10.0 * (double)time);
		// (add the factor of 10 so that smoothnesses don't have to be tiny numbers)

		double delta = (m_Target - m_Current) * (1.0 - p);
		m_Current += delta;
		return (float)delta;
	}

	void ClampSmoothly(float min, float max)
	{
		m_Target = Clamp(m_Target, (double)min, (double)max);
	}

	// Wrap so 'target' is in the range [min, max]
	void Wrap(float min, float max)
	{
		double t = fmod(m_Target - min, (double)(max - min));
		if (t < 0)
			t += max - min;
		t += min;

		m_Current += t - m_Target;
		m_Target = t;
	}

private:
	double m_Target; // the value which m_Current is tending towards
	double m_Current;
	// (We use double because the extra precision is worthwhile here)

	float m_MinDelta; // cutoff where we stop moving (to avoid ugly shimmering effects)
public:
	float m_Smoothness;
};

class CGameViewImpl : public CJSObject<CGameViewImpl>
{
	NONCOPYABLE(CGameViewImpl);
public:
	CGameViewImpl(CGame* game)
		: Game(game),
		ColladaManager(), MeshManager(ColladaManager), SkeletonAnimManager(ColladaManager),
		ObjectManager(MeshManager, SkeletonAnimManager, *game->GetSimulation2()),
		ViewCamera(),
		CullCamera(),
		LockCullCamera(false),
		ConstrainCamera(true),
		Culling(true),
		FollowEntity(INVALID_ENTITY),
		FollowFirstPerson(false),

		// Dummy values (these will be filled in by the config file)
		ViewScrollSpeed(0),
		ViewRotateXSpeed(0),
		ViewRotateXMin(0),
		ViewRotateXMax(0),
		ViewRotateXDefault(0),
		ViewRotateYSpeed(0),
		ViewRotateYSpeedWheel(0),
		ViewRotateYDefault(0),
		ViewDragSpeed(0),
		ViewZoomSpeed(0),
		ViewZoomSpeedWheel(0),
		ViewZoomMin(0),
		ViewZoomMax(0),
		ViewZoomDefault(0),
		JoystickPanX(-1),
		JoystickPanY(-1),
		JoystickRotateX(-1),
		JoystickRotateY(-1),
		JoystickZoomIn(-1),
		JoystickZoomOut(-1),

		PosX(0, 0, 0.01f),
		PosY(0, 0, 0.01f),
		PosZ(0, 0, 0.01f),
		Zoom(0, 0, 0.1f),
		RotateX(0, 0, 0.001f),
		RotateY(0, 0, 0.001f)
	{
	}

	CGame* Game;
	CColladaManager ColladaManager;
	CMeshManager MeshManager;
	CSkeletonAnimManager SkeletonAnimManager;
	CObjectManager ObjectManager;
	CLOSTexture LOSTexture;

	/**
	 * this camera controls the eye position when rendering
	 */
	CCamera ViewCamera;

	/**
	 * this camera controls the frustum that is used for culling
	 * and shadow calculations
	 *
	 * Note that all code that works with camera movements should only change
	 * m_ViewCamera. The render functions automatically sync the cull camera to
	 * the view camera depending on the value of m_LockCullCamera.
	 */
	CCamera CullCamera;

	/**
	 * When @c true, the cull camera is locked in place.
	 * When @c false, the cull camera follows the view camera.
	 *
	 * Exposed to JS as gameView.lockCullCamera
	 */
	bool LockCullCamera;

	/**
	 * When @c true, culling is enabled so that only models that have a chance of
	 * being visible are sent to the renderer.
	 * Otherwise, the entire world is sent to the renderer.
	 *
	 * Exposed to JS as gameView.culling
	 */
	bool Culling;

	/**
	 * Whether the camera movement should be constrained by min/max limits
	 * and terrain avoidance.
	 */
	bool ConstrainCamera;

	/**
	 * Cache global lighting environment. This is used  to check whether the
	 * environment has changed during the last frame, so that vertex data can be updated etc.
	 */
	CLightEnv CachedLightEnv;

	CCinemaManager TrackManager;

	/**
	 * Entity for the camera to follow, or INVALID_ENTITY if none.
	 */
	entity_id_t FollowEntity;

	/**
	 * Whether to follow FollowEntity in first-person mode.
	 */
	bool FollowFirstPerson;

	////////////////////////////////////////
	// Settings
	float ViewScrollSpeed;
	float ViewRotateXSpeed;
	float ViewRotateXMin;
	float ViewRotateXMax;
	float ViewRotateXDefault;
	float ViewRotateYSpeed;
	float ViewRotateYSpeedWheel;
	float ViewRotateYDefault;
	float ViewDragSpeed;
	float ViewZoomSpeed;
	float ViewZoomSpeedWheel;
	float ViewZoomMin;
	float ViewZoomMax;
	float ViewZoomDefault;
	int JoystickPanX;
	int JoystickPanY;
	int JoystickRotateX;
	int JoystickRotateY;
	int JoystickZoomIn;
	int JoystickZoomOut;

	////////////////////////////////////////
	// Camera Controls State
	CSmoothedValue PosX;
	CSmoothedValue PosY;
	CSmoothedValue PosZ;
	CSmoothedValue Zoom;
	CSmoothedValue RotateX; // inclination around x axis (relative to camera)
	CSmoothedValue RotateY; // rotation around y (vertical) axis

	static void ScriptingInit();
};

static void SetupCameraMatrixSmooth(CGameViewImpl* m, CMatrix3D* orientation)
{
	orientation->SetIdentity();
	orientation->RotateX(m->RotateX.GetSmoothedValue());
	orientation->RotateY(m->RotateY.GetSmoothedValue());
	orientation->Translate(m->PosX.GetSmoothedValue(), m->PosY.GetSmoothedValue(), m->PosZ.GetSmoothedValue());
}

static void SetupCameraMatrixSmoothRot(CGameViewImpl* m, CMatrix3D* orientation)
{
	orientation->SetIdentity();
	orientation->RotateX(m->RotateX.GetSmoothedValue());
	orientation->RotateY(m->RotateY.GetSmoothedValue());
	orientation->Translate(m->PosX.GetValue(), m->PosY.GetValue(), m->PosZ.GetValue());
}

static void SetupCameraMatrixNonSmooth(CGameViewImpl* m, CMatrix3D* orientation)
{
	orientation->SetIdentity();
	orientation->RotateX(m->RotateX.GetValue());
	orientation->RotateY(m->RotateY.GetValue());
	orientation->Translate(m->PosX.GetValue(), m->PosY.GetValue(), m->PosZ.GetValue());
}

CGameView::CGameView(CGame *pGame):
	m(new CGameViewImpl(pGame))
{
	SViewPort vp;
	vp.m_X=0;
	vp.m_Y=0;
	vp.m_Width=g_xres;
	vp.m_Height=g_yres;
	m->ViewCamera.SetViewPort(vp);

	m->ViewCamera.SetProjection(defaultNear, defaultFar, defaultFOV);
	SetupCameraMatrixSmooth(m, &m->ViewCamera.m_Orientation);
	m->ViewCamera.UpdateFrustum();

	m->CullCamera = m->ViewCamera;
	g_Renderer.SetSceneCamera(m->ViewCamera, m->CullCamera);
}

CGameView::~CGameView()
{
	UnloadResources();

	delete m;
}

void CGameView::SetViewport(const SViewPort& vp)
{
	m->ViewCamera.SetViewPort(vp);
	m->ViewCamera.SetProjection(defaultNear, defaultFar, defaultFOV);
}

CObjectManager& CGameView::GetObjectManager() const
{
	return m->ObjectManager;
}

JSObject* CGameView::GetScript()
{
	return m->GetScript();
}

/*static*/ void CGameView::ScriptingInit()
{
	return CGameViewImpl::ScriptingInit();
}

CCamera* CGameView::GetCamera()
{
	return &m->ViewCamera;
}

CCinemaManager* CGameView::GetCinema()
{
	return &m->TrackManager;
};

CLOSTexture& CGameView::GetLOSTexture()
{
	return m->LOSTexture;
}


void CGameViewImpl::ScriptingInit()
{
	AddProperty(L"culling", &CGameViewImpl::Culling);
	AddProperty(L"lockCullCamera", &CGameViewImpl::LockCullCamera);
	AddProperty(L"constrainCamera", &CGameViewImpl::ConstrainCamera);

	CJSObject<CGameViewImpl>::ScriptingInit("GameView");
}

int CGameView::Initialize()
{
	CFG_GET_SYS_VAL("view.scroll.speed", Float, m->ViewScrollSpeed);
	CFG_GET_SYS_VAL("view.rotate.x.speed", Float, m->ViewRotateXSpeed);
	CFG_GET_SYS_VAL("view.rotate.x.min", Float, m->ViewRotateXMin);
	CFG_GET_SYS_VAL("view.rotate.x.max", Float, m->ViewRotateXMax);
	CFG_GET_SYS_VAL("view.rotate.x.default", Float, m->ViewRotateXDefault);
	CFG_GET_SYS_VAL("view.rotate.y.speed", Float, m->ViewRotateYSpeed);
	CFG_GET_SYS_VAL("view.rotate.y.speed.wheel", Float, m->ViewRotateYSpeedWheel);
	CFG_GET_SYS_VAL("view.rotate.y.default", Float, m->ViewRotateYDefault);
	CFG_GET_SYS_VAL("view.drag.speed", Float, m->ViewDragSpeed);
	CFG_GET_SYS_VAL("view.zoom.speed", Float, m->ViewZoomSpeed);
	CFG_GET_SYS_VAL("view.zoom.speed.wheel", Float, m->ViewZoomSpeedWheel);
	CFG_GET_SYS_VAL("view.zoom.min", Float, m->ViewZoomMin);
	CFG_GET_SYS_VAL("view.zoom.max", Float, m->ViewZoomMax);
	CFG_GET_SYS_VAL("view.zoom.default", Float, m->ViewZoomDefault);

	CFG_GET_SYS_VAL("joystick.camera.pan.x", Int, m->JoystickPanX);
	CFG_GET_SYS_VAL("joystick.camera.pan.y", Int, m->JoystickPanY);
	CFG_GET_SYS_VAL("joystick.camera.rotate.x", Int, m->JoystickRotateX);
	CFG_GET_SYS_VAL("joystick.camera.rotate.y", Int, m->JoystickRotateY);
	CFG_GET_SYS_VAL("joystick.camera.zoom.in", Int, m->JoystickZoomIn);
	CFG_GET_SYS_VAL("joystick.camera.zoom.out", Int, m->JoystickZoomOut);

	CFG_GET_SYS_VAL("view.pos.smoothness", Float, m->PosX.m_Smoothness);
	CFG_GET_SYS_VAL("view.pos.smoothness", Float, m->PosY.m_Smoothness);
	CFG_GET_SYS_VAL("view.pos.smoothness", Float, m->PosZ.m_Smoothness);
	CFG_GET_SYS_VAL("view.zoom.smoothness", Float, m->Zoom.m_Smoothness);
	CFG_GET_SYS_VAL("view.rotate.x.smoothness", Float, m->RotateX.m_Smoothness);
	CFG_GET_SYS_VAL("view.rotate.y.smoothness", Float, m->RotateY.m_Smoothness);

	m->RotateX.SetValue(DEGTORAD(m->ViewRotateXDefault));
	m->RotateY.SetValue(DEGTORAD(m->ViewRotateYDefault));

	return 0;
}



void CGameView::RegisterInit()
{
	// CGameView init
	RegMemFun(this, &CGameView::Initialize, L"CGameView init", 1);

	// previously done by CGameView::InitResources
	RegMemFun(g_TexMan.GetSingletonPtr(), &CTerrainTextureManager::LoadTerrainTextures, L"LoadTerrainTextures", 60);
	RegMemFun(g_Renderer.GetSingletonPtr(), &CRenderer::LoadAlphaMaps, L"LoadAlphaMaps", 5);
	RegMemFun(g_Renderer.GetSingletonPtr()->GetWaterManager(), &WaterManager::LoadWaterTextures, L"LoadWaterTextures", 80);
}


void CGameView::BeginFrame()
{
	if (m->LockCullCamera == false)
	{
		// Set up cull camera
		m->CullCamera = m->ViewCamera;

		// One way to fix shadows popping in at the edge of the screen is to widen the culling frustum so that
		// objects aren't culled as early. The downside is that objects will get rendered even though they appear
		// off screen, which is somewhat inefficient. A better solution would be to decouple shadow map rendering
		// from model rendering; as it is now, a shadow map is only rendered if its associated model is to be
		// rendered.
		// (See http://trac.wildfiregames.com/ticket/504)
		m->CullCamera.SetProjection(defaultNear, defaultFar, defaultCullFOV);
		m->CullCamera.UpdateFrustum();
	}
	g_Renderer.SetSceneCamera(m->ViewCamera, m->CullCamera);

	CheckLightEnv();

	m->Game->CachePlayerColours();
}

void CGameView::Render()
{
	g_Renderer.RenderScene(this);
}

///////////////////////////////////////////////////////////
// This callback is part of the Scene interface
// Submit all objects visible in the given frustum
void CGameView::EnumerateObjects(const CFrustum& frustum, SceneCollector* c)
{
	PROFILE_START( "submit terrain" );
	CTerrain* pTerrain = m->Game->GetWorld()->GetTerrain();
	const ssize_t patchesPerSide = pTerrain->GetPatchesPerSide();

	// find out which patches will be drawn
	for (ssize_t j=0; j<patchesPerSide; j++) {
		for (ssize_t i=0; i<patchesPerSide; i++) {
			CPatch* patch=pTerrain->GetPatch(i,j);	// can't fail

			// If the patch is underwater, calculate a bounding box that also contains the water plane
			CBound bounds = patch->GetBounds();
			float waterHeight = g_Renderer.GetWaterManager()->m_WaterHeight + 0.001f;
			if(bounds[1].Y < waterHeight) {
				bounds[1].Y = waterHeight;
			}
			
			if (!m->Culling || frustum.IsBoxVisible (CVector3D(0,0,0), bounds)) {
				//c->Submit(patch);

				// set the renderstate for this patch
				patch->setDrawState(true);

				// set the renderstate for the neighbors
				CPatch *nPatch;

				nPatch = pTerrain->GetPatch(i-1,j-1);
				if(nPatch) nPatch->setDrawState(true);

				nPatch = pTerrain->GetPatch(i,j-1);
				if(nPatch) nPatch->setDrawState(true);

				nPatch = pTerrain->GetPatch(i+1,j-1);
				if(nPatch) nPatch->setDrawState(true);

				nPatch = pTerrain->GetPatch(i-1,j);
				if(nPatch) nPatch->setDrawState(true);

				nPatch = pTerrain->GetPatch(i+1,j);
				if(nPatch) nPatch->setDrawState(true);

				nPatch = pTerrain->GetPatch(i-1,j+1);
				if(nPatch) nPatch->setDrawState(true);

				nPatch = pTerrain->GetPatch(i,j+1);
				if(nPatch) nPatch->setDrawState(true);

				nPatch = pTerrain->GetPatch(i+1,j+1);
				if(nPatch) nPatch->setDrawState(true);
			}
		}
	}

	// draw the patches
	for (ssize_t j=0; j<patchesPerSide; j++)
	{
		for (ssize_t i=0; i<patchesPerSide; i++)
		{
			CPatch* patch=pTerrain->GetPatch(i,j);	// can't fail
			if(patch->getDrawState() == true)
			{
				c->Submit(patch);
				patch->setDrawState(false);
			}
		}
	}
	PROFILE_END( "submit terrain" );

	PROFILE_START( "submit sim components" );
	m->Game->GetSimulation2()->RenderSubmit(*c, frustum, m->Culling);
	PROFILE_END( "submit sim components" );
}


void CGameView::CheckLightEnv()
{
	if (m->CachedLightEnv == g_LightEnv)
		return;

	if (m->CachedLightEnv.GetLightingModel() != g_LightEnv.GetLightingModel())
		g_Renderer.MakeShadersDirty();

	m->CachedLightEnv = g_LightEnv;
	CTerrain* pTerrain = m->Game->GetWorld()->GetTerrain();

	if (!pTerrain)
		return;

	PROFILE("update light env");
	pTerrain->MakeDirty(RENDERDATA_UPDATE_COLOR);

	const std::vector<CUnit*>& units = m->Game->GetWorld()->GetUnitManager().GetUnits();
	for (size_t i = 0; i < units.size(); ++i)
		units[i]->GetModel().SetDirtyRec(RENDERDATA_UPDATE_COLOR);
}


void CGameView::UnloadResources()
{
	g_TexMan.UnloadTerrainTextures();
	g_Renderer.UnloadAlphaMaps();
	g_Renderer.GetWaterManager()->UnloadWaterTextures();
}


static void ClampDistance(CGameViewImpl* m, bool smooth)
{
	if (!m->ConstrainCamera)
		return;

	CCamera targetCam = m->ViewCamera;
	SetupCameraMatrixSmoothRot(m, &targetCam.m_Orientation);

	CVector3D forwards = targetCam.m_Orientation.GetIn();

	CVector3D delta = targetCam.GetFocus() - targetCam.m_Orientation.GetTranslation();

	float dist = delta.Dot(forwards);
	float clampedDist = Clamp(dist, m->ViewZoomMin, m->ViewZoomMax);
	float diff = clampedDist - dist;

	if (!diff)
		return;

	if (smooth)
	{
		m->PosX.AddSmoothly(forwards.X * -diff);
		m->PosY.AddSmoothly(forwards.Y * -diff);
		m->PosZ.AddSmoothly(forwards.Z * -diff);
	}
	else
	{
		m->PosX.Add(forwards.X * -diff);
		m->PosY.Add(forwards.Y * -diff);
		m->PosZ.Add(forwards.Z * -diff);
	}
}

void CGameView::Update(float DeltaTime)
{
	if (!g_app_has_focus)
		return;

	// TODO: this is probably not an ideal place for this, it should probably go
	// in a CCmpWaterManager or some such thing (once such a thing exists)
	if (!m->Game->m_Paused)
		g_Renderer.GetWaterManager()->m_WaterTexTimer += DeltaTime;

	if (m->TrackManager.IsActive() && m->TrackManager.IsPlaying())
	{
		if (! m->TrackManager.Update(DeltaTime))
		{
//			ResetCamera();
		}
		return;
	}

	// Calculate mouse movement
	static int mouse_last_x = 0;
	static int mouse_last_y = 0;
	int mouse_dx = g_mouse_x - mouse_last_x;
	int mouse_dy = g_mouse_y - mouse_last_y;
	mouse_last_x = g_mouse_x;
	mouse_last_y = g_mouse_y;

	if (HotkeyIsPressed("camera.rotate.cw"))
		m->RotateY.AddSmoothly(m->ViewRotateYSpeed * DeltaTime);
	if (HotkeyIsPressed("camera.rotate.ccw"))
		m->RotateY.AddSmoothly(-m->ViewRotateYSpeed * DeltaTime);
	if (HotkeyIsPressed("camera.rotate.up"))
		m->RotateX.AddSmoothly(-m->ViewRotateXSpeed * DeltaTime);
	if (HotkeyIsPressed("camera.rotate.down"))
		m->RotateX.AddSmoothly(m->ViewRotateXSpeed * DeltaTime);

	float moveRightward = 0.f;
	float moveForward = 0.f;

	if (HotkeyIsPressed("camera.pan"))
	{
		moveRightward += m->ViewDragSpeed * mouse_dx;
		moveForward += m->ViewDragSpeed * -mouse_dy;
	}

	if (g_mouse_active)
	{
		if (g_mouse_x >= g_xres - 2 && g_mouse_x < g_xres)
			moveRightward += m->ViewScrollSpeed * DeltaTime;
		else if (g_mouse_x <= 3 && g_mouse_x >= 0)
			moveRightward -= m->ViewScrollSpeed * DeltaTime;

		if (g_mouse_y >= g_yres - 2 && g_mouse_y < g_yres)
			moveForward -= m->ViewScrollSpeed * DeltaTime;
		else if (g_mouse_y <= 3 && g_mouse_y >= 0)
			moveForward += m->ViewScrollSpeed * DeltaTime;
	}

	if (HotkeyIsPressed("camera.right"))
		moveRightward += m->ViewScrollSpeed * DeltaTime;
	if (HotkeyIsPressed("camera.left"))
		moveRightward -= m->ViewScrollSpeed * DeltaTime;
	if (HotkeyIsPressed("camera.up"))
		moveForward += m->ViewScrollSpeed * DeltaTime;
	if (HotkeyIsPressed("camera.down"))
		moveForward -= m->ViewScrollSpeed * DeltaTime;

	if (g_Joystick.IsEnabled())
	{
		// This could all be improved with extra speed and sensitivity settings
		// (maybe use pow to allow finer control?), and inversion settings

		moveRightward += g_Joystick.GetAxisValue(m->JoystickPanX) * m->ViewScrollSpeed * DeltaTime;
		moveForward -= g_Joystick.GetAxisValue(m->JoystickPanY) * m->ViewScrollSpeed * DeltaTime;

		m->RotateX.AddSmoothly(g_Joystick.GetAxisValue(m->JoystickRotateX) * m->ViewRotateXSpeed * DeltaTime);
		m->RotateY.AddSmoothly(-g_Joystick.GetAxisValue(m->JoystickRotateY) * m->ViewRotateYSpeed * DeltaTime);

		// Use a +1 bias for zoom because I want this to work with trigger buttons that default to -1
		m->Zoom.AddSmoothly((g_Joystick.GetAxisValue(m->JoystickZoomIn) + 1.0f) / 2.0f * m->ViewZoomSpeed * DeltaTime);
		m->Zoom.AddSmoothly(-(g_Joystick.GetAxisValue(m->JoystickZoomOut) + 1.0f) / 2.0f * m->ViewZoomSpeed * DeltaTime);
	}

	if (moveRightward || moveForward)
	{
		// Break out of following mode when the user starts scrolling
		m->FollowEntity = INVALID_ENTITY;

		float s = sin(m->RotateY.GetSmoothedValue());
		float c = cos(m->RotateY.GetSmoothedValue());
		m->PosX.AddSmoothly(c * moveRightward);
		m->PosZ.AddSmoothly(-s * moveRightward);
		m->PosX.AddSmoothly(s * moveForward);
		m->PosZ.AddSmoothly(c * moveForward);
	}

	if (m->FollowEntity)
	{
		CmpPtr<ICmpPosition> cmpPosition(*(m->Game->GetSimulation2()), m->FollowEntity);
		if (!cmpPosition.null() && cmpPosition->IsInWorld())
		{
			// Get the most recent interpolated position
			float frameOffset = m->Game->GetSimulation2()->GetLastFrameOffset();
			CMatrix3D transform = cmpPosition->GetInterpolatedTransform(frameOffset, false);
			CVector3D pos = transform.GetTranslation();

			if (m->FollowFirstPerson)
			{
				float x, z, angle;
				cmpPosition->GetInterpolatedPosition2D(frameOffset, x, z, angle);
				float height = 4.f;
				m->ViewCamera.m_Orientation.SetIdentity();
				m->ViewCamera.m_Orientation.RotateX((float)M_PI/24.f);
				m->ViewCamera.m_Orientation.RotateY(angle);
				m->ViewCamera.m_Orientation.Translate(pos.X, pos.Y + height, pos.Z);

				m->ViewCamera.UpdateFrustum();
				return;
			}
			else
			{
				// Move the camera to match the unit
				CCamera targetCam = m->ViewCamera;
				SetupCameraMatrixSmoothRot(m, &targetCam.m_Orientation);

				CVector3D pivot = targetCam.GetFocus();
				CVector3D delta = pos - pivot;
				m->PosX.AddSmoothly(delta.X);
				m->PosY.AddSmoothly(delta.Y);
				m->PosZ.AddSmoothly(delta.Z);
			}
		}
		else
		{
			// The unit disappeared (died or garrisoned etc), so stop following it
			m->FollowEntity = INVALID_ENTITY;
		}
	}

	if (HotkeyIsPressed("camera.zoom.in"))
		m->Zoom.AddSmoothly(m->ViewZoomSpeed * DeltaTime);
	if (HotkeyIsPressed("camera.zoom.out"))
		m->Zoom.AddSmoothly(-m->ViewZoomSpeed * DeltaTime);

	float zoomDelta = m->Zoom.Update(DeltaTime);
	if (zoomDelta)
	{
		CVector3D forwards = m->ViewCamera.m_Orientation.GetIn();
		m->PosX.AddSmoothly(forwards.X * zoomDelta);
		m->PosY.AddSmoothly(forwards.Y * zoomDelta);
		m->PosZ.AddSmoothly(forwards.Z * zoomDelta);
	}

	if (m->ConstrainCamera)
		m->RotateX.ClampSmoothly(DEGTORAD(m->ViewRotateXMin), DEGTORAD(m->ViewRotateXMax));

	ClampDistance(m, true);

	// Ensure the ViewCamera focus is inside the map with the chosen margins
	// if not so - apply margins to the camera
	if (m->ConstrainCamera)
	{
		CCamera targetCam = m->ViewCamera;
		SetupCameraMatrixSmoothRot(m, &targetCam.m_Orientation);

		CTerrain* pTerrain = m->Game->GetWorld()->GetTerrain();

		CVector3D pivot = targetCam.GetFocus();
		CVector3D delta = targetCam.m_Orientation.GetTranslation() - pivot;

		CVector3D desiredPivot = pivot;

		CmpPtr<ICmpRangeManager> cmpRangeManager(*m->Game->GetSimulation2(), SYSTEM_ENTITY);
		if (!cmpRangeManager.null() && cmpRangeManager->GetLosCircular())
		{
			// Clamp to a circular region around the center of the map
			float r = pTerrain->GetMaxX() / 2;
			CVector3D center(r, desiredPivot.Y, r);
			float dist = (desiredPivot - center).Length();
			if (dist > r + CAMERA_EDGE_MARGIN)
				desiredPivot = center + (desiredPivot - center).Normalized() * (r + CAMERA_EDGE_MARGIN);
		}
		else
		{
			// Clamp to the square edges of the map
			desiredPivot.X = Clamp(desiredPivot.X, pTerrain->GetMinX() - CAMERA_EDGE_MARGIN, pTerrain->GetMaxX() + CAMERA_EDGE_MARGIN);
			desiredPivot.Z = Clamp(desiredPivot.Z, pTerrain->GetMinZ() - CAMERA_EDGE_MARGIN, pTerrain->GetMaxZ() + CAMERA_EDGE_MARGIN);
		}

		// Update the position so that pivot is within the margin
		m->PosX.SetValueSmoothly(desiredPivot.X + delta.X);
		m->PosZ.SetValueSmoothly(desiredPivot.Z + delta.Z);
	}

	m->PosX.Update(DeltaTime);
	m->PosY.Update(DeltaTime);
	m->PosZ.Update(DeltaTime);

	// Handle rotation around the Y (vertical) axis
	{
		CCamera targetCam = m->ViewCamera;
		SetupCameraMatrixSmooth(m, &targetCam.m_Orientation);

		float rotateYDelta = m->RotateY.Update(DeltaTime);
		if (rotateYDelta)
		{
			// We've updated RotateY, and need to adjust Pos so that it's still
			// facing towards the original focus point (the terrain in the center
			// of the screen).

			CVector3D upwards(0.0f, 1.0f, 0.0f);

			CVector3D pivot = targetCam.GetFocus();
			CVector3D delta = targetCam.m_Orientation.GetTranslation() - pivot;

			CQuaternion q;
			q.FromAxisAngle(upwards, rotateYDelta);
			CVector3D d = q.Rotate(delta) - delta;

			m->PosX.Add(d.X);
			m->PosY.Add(d.Y);
			m->PosZ.Add(d.Z);
		}
	}

	// Handle rotation around the X (sideways, relative to camera) axis
	{
		CCamera targetCam = m->ViewCamera;
		SetupCameraMatrixSmooth(m, &targetCam.m_Orientation);

		float rotateXDelta = m->RotateX.Update(DeltaTime);
		if (rotateXDelta)
		{
			CVector3D rightwards = targetCam.m_Orientation.GetLeft() * -1.0f;

			CVector3D pivot = m->ViewCamera.GetFocus();
			CVector3D delta = targetCam.m_Orientation.GetTranslation() - pivot;

			CQuaternion q;
			q.FromAxisAngle(rightwards, rotateXDelta);
			CVector3D d = q.Rotate(delta) - delta;

			m->PosX.Add(d.X);
			m->PosY.Add(d.Y);
			m->PosZ.Add(d.Z);
		}
	}

	/* This is disabled since it doesn't seem necessary:

	// Ensure the camera's near point is never inside the terrain
	if (m->ConstrainCamera)
	{
		CMatrix3D target;
		target.SetIdentity();
		target.RotateX(m->RotateX.GetValue());
		target.RotateY(m->RotateY.GetValue());
		target.Translate(m->PosX.GetValue(), m->PosY.GetValue(), m->PosZ.GetValue());

		CVector3D nearPoint = target.GetTranslation() + target.GetIn() * defaultNear;
		float ground = m->Game->GetWorld()->GetTerrain()->GetExactGroundLevel(nearPoint.X, nearPoint.Z);
		float limit = ground + 16.f;
		if (nearPoint.Y < limit)
			m->PosY.AddSmoothly(limit - nearPoint.Y);
	}
	*/

	m->RotateY.Wrap(-(float)M_PI, (float)M_PI);

	// Update the camera matrix
	SetupCameraMatrixSmooth(m, &m->ViewCamera.m_Orientation);
	m->ViewCamera.UpdateFrustum();
}

void CGameView::MoveCameraTarget(const CVector3D& target, bool minimap)
{
	// Maintain the same orientation and level of zoom, if we can
	// (do this by working out the point the camera is looking at, saving
	//  the difference between that position and the camera point, and restoring
	//  that difference to our new target)

	CCamera targetCam = m->ViewCamera;
	SetupCameraMatrixNonSmooth(m, &targetCam.m_Orientation);

	CVector3D pivot = targetCam.GetFocus();
	CVector3D delta = target - pivot;
	
	//If minimap movement, maintain previous zoom level by not changing Y position
	//	- this prevents strange behavior when moving across changes in terrain height
	if (!minimap)
		m->PosY.SetValueSmoothly(delta.Y + m->PosY.GetValue());

	m->PosX.SetValueSmoothly(delta.X + m->PosX.GetValue());
	m->PosZ.SetValueSmoothly(delta.Z + m->PosZ.GetValue());

	ClampDistance(m, false);

	// Break out of following mode so the camera really moves to the target
	m->FollowEntity = INVALID_ENTITY;
}

void CGameView::ResetCameraTarget(const CVector3D& target)
{
	CMatrix3D orientation;
	orientation.SetIdentity();
	orientation.RotateX(DEGTORAD(m->ViewRotateXDefault));
	orientation.RotateY(DEGTORAD(m->ViewRotateYDefault));

	CVector3D delta = orientation.GetIn() * m->ViewZoomDefault;
	m->PosX.SetValue(target.X - delta.X);
	m->PosY.SetValue(target.Y - delta.Y);
	m->PosZ.SetValue(target.Z - delta.Z);

	ClampDistance(m, false);

	SetupCameraMatrixSmooth(m, &m->ViewCamera.m_Orientation);
	m->ViewCamera.UpdateFrustum();

	// Break out of following mode so the camera really moves to the target
	m->FollowEntity = INVALID_ENTITY;
}

void CGameView::ResetCameraAngleZoom()
{
	CCamera targetCam = m->ViewCamera;
	SetupCameraMatrixNonSmooth(m, &targetCam.m_Orientation);

	// Compute the zoom adjustment to get us back to the default
	CVector3D forwards = targetCam.m_Orientation.GetIn();
	CVector3D delta = targetCam.GetFocus() - targetCam.m_Orientation.GetTranslation();
	float dist = delta.Dot(forwards);
	m->Zoom.AddSmoothly(dist - m->ViewZoomDefault);

	// Reset orientations to default
	m->RotateX.SetValueSmoothly(DEGTORAD(m->ViewRotateXDefault));
	m->RotateY.SetValueSmoothly(DEGTORAD(m->ViewRotateYDefault));
}

void CGameView::CameraFollow(entity_id_t entity, bool firstPerson)
{
	m->FollowEntity = entity;
	m->FollowFirstPerson = firstPerson;
}

InReaction game_view_handler(const SDL_Event_* ev)
{
	// put any events that must be processed even if inactive here

	if(!g_app_has_focus || !g_Game)
		return IN_PASS;

	CGameView *pView=g_Game->GetView();

	return pView->HandleEvent(ev);
}

InReaction CGameView::HandleEvent(const SDL_Event_* ev)
{
	switch(ev->ev.type)
	{

	case SDL_HOTKEYDOWN:
		std::string hotkey = static_cast<const char*>(ev->ev.user.data1);

		if (hotkey == "wireframe")
		{
			if (g_Renderer.GetModelRenderMode() == SOLID)
			{
				g_Renderer.SetTerrainRenderMode(EDGED_FACES);
				g_Renderer.SetModelRenderMode(EDGED_FACES);
			}
			else if (g_Renderer.GetModelRenderMode() == EDGED_FACES)
			{
				g_Renderer.SetTerrainRenderMode(WIREFRAME);
				g_Renderer.SetModelRenderMode(WIREFRAME);
			}
			else
			{
				g_Renderer.SetTerrainRenderMode(SOLID);
				g_Renderer.SetModelRenderMode(SOLID);
			}
			return IN_HANDLED;
		}
		// Mouse wheel must be treated using events instead of polling,
		// because SDL auto-generates a sequence of mousedown/mouseup events
		// and we never get to see the "down" state inside Update().
		else if (hotkey == "camera.zoom.wheel.in")
		{
			m->Zoom.AddSmoothly(m->ViewZoomSpeedWheel);
			return IN_HANDLED;
		}
		else if (hotkey == "camera.zoom.wheel.out")
		{
			m->Zoom.AddSmoothly(-m->ViewZoomSpeedWheel);
			return IN_HANDLED;
		}
		else if (hotkey == "camera.rotate.wheel.cw")
		{
			m->RotateY.AddSmoothly(m->ViewRotateYSpeedWheel);
			return IN_HANDLED;
		}
		else if (hotkey == "camera.rotate.wheel.ccw")
		{
			m->RotateY.AddSmoothly(-m->ViewRotateYSpeedWheel);
			return IN_HANDLED;
		}
		else if (hotkey == "camera.reset")
		{
			ResetCameraAngleZoom();
			return IN_HANDLED;
		}
	}

	return IN_PASS;
}