/** 
 * @file llvosky.h
 * @brief LLVOSky class header file
 *
 * $LicenseInfo:firstyear=2001&license=viewerlgpl$
 * Second Life Viewer Source Code
 * Copyright (C) 2010, Linden Research, Inc.
 * 
 * This library is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public
 * License as published by the Free Software Foundation;
 * version 2.1 of the License only.
 * 
 * This library 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
 * Lesser General Public License for more details.
 * 
 * You should have received a copy of the GNU Lesser General Public
 * License along with this library; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301  USA
 * 
 * Linden Research, Inc., 945 Battery Street, San Francisco, CA  94111  USA
 * $/LicenseInfo$
 */

#ifndef LL_LLVOSKY_H
#define LL_LLVOSKY_H

#include "stdtypes.h"
#include "v3color.h"
#include "v4coloru.h"
#include "llviewertexture.h"
#include "llviewerobject.h"
#include "llframetimer.h"
#include "v3colorutil.h"
#include "llsettingssky.h"
#include "lllegacyatmospherics.h"

const F32 SKY_BOX_MULT			= 16.0f;
const F32 HEAVENLY_BODY_DIST	= HORIZON_DIST - 10.f;
const F32 HEAVENLY_BODY_FACTOR	= 0.1f;
const F32 HEAVENLY_BODY_SCALE	= HEAVENLY_BODY_DIST * HEAVENLY_BODY_FACTOR;

// HACK: Allow server to change sun and moon IDs.
// I can't figure out how to pass the appropriate
// information into the LLVOSky constructor.  JC
extern LLUUID gSunTextureID;
extern LLUUID gMoonTextureID;

class LLFace;
class LLHaze;

class LLSkyTex
{
	friend class LLVOSky;
private:
	static S32		sResolution;
	static S32		sComponents;
	LLPointer<LLViewerTexture> mTexture[2];
	LLPointer<LLImageRaw> mImageRaw[2];
	LLColor4		*mSkyData;
	LLVector3		*mSkyDirs;			// Cache of sky direction vectors
	static S32		sCurrent;
	static F32		sInterpVal;

public:
	static F32 getInterpVal()					{ return sInterpVal; }
	static void setInterpVal(const F32 v)		{ sInterpVal = v; }
	static BOOL doInterpolate()					{ return sInterpVal > 0.001f; }

	void bindTexture(BOOL curr = TRUE);
	
protected:
	LLSkyTex();
	void init();
	void cleanupGL();
	void restoreGL();

	~LLSkyTex();


	static S32 getResolution()					{ return sResolution; }
	static S32 getCurrent()						{ return sCurrent; }
	static S32 stepCurrent()					{ sCurrent++; sCurrent &= 1; return sCurrent; }
	static S32 getNext()						{ return ((sCurrent+1) & 1); }
	static S32 getWhich(const BOOL curr)		{ return curr ? sCurrent : getNext(); }

	void initEmpty(const S32 tex);
	
	void create(F32 brightness);

	void setDir(const LLVector3 &dir, const S32 i, const S32 j)
	{
		S32 offset = i * sResolution + j;
		mSkyDirs[offset] = dir;
	}

	const LLVector3 &getDir(const S32 i, const S32 j) const
	{
		S32 offset = i * sResolution + j;
		return mSkyDirs[offset];
	}

	void setPixel(const LLColor4 &col, const S32 i, const S32 j)
	{
		S32 offset = i * sResolution + j;
		mSkyData[offset] = col;
	}

	void setPixel(const LLColor4U &col, const S32 i, const S32 j)
	{
		S32 offset = (i * sResolution + j) * sComponents;
		U32* pix = (U32*) &(mImageRaw[sCurrent]->getData()[offset]);
		*pix = col.asRGBA();
	}

	LLColor4U getPixel(const S32 i, const S32 j)
	{
		LLColor4U col;
		S32 offset = (i * sResolution + j) * sComponents;
		U32* pix = (U32*) &(mImageRaw[sCurrent]->getData()[offset]);
		col.fromRGBA( *pix );
		return col;
	}

	LLImageRaw* getImageRaw(BOOL curr=TRUE)			{ return mImageRaw[getWhich(curr)]; }
	void createGLImage(BOOL curr=TRUE);
};

/// TODO Move into the stars draw pool (and rename them appropriately).
class LLHeavenBody
{
protected:
	LLVector3		mDirectionCached;		// hack for events that shouldn't happen every frame

	LLColor3		mColor;
	LLColor3		mColorCached;
	F32				mIntensity;
	LLVector3		mDirection;				// direction of the local heavenly body
	LLVector3		mAngularVelocity;		// velocity of the local heavenly body

	F32				mDiskRadius;
	BOOL			mDraw;					// FALSE - do not draw.
	F32				mHorizonVisibility;		// number [0, 1] due to how horizon
	F32				mVisibility;			// same but due to other objects being in throng.
	BOOL			mVisible;
	static F32		sInterpVal;
	LLVector3		mQuadCorner[4];
	LLVector3		mO;

public:
	LLHeavenBody(const F32 rad) :
		mDirectionCached(LLVector3(0,0,0)),
		mDirection(LLVector3(0,0,0)),
		mIntensity(0.f),
		mDiskRadius(rad), mDraw(FALSE),
		mHorizonVisibility(1.f), mVisibility(1.f),
		mVisible(FALSE)
	{
		mColor.setToBlack();
		mColorCached.setToBlack();
	}
	~LLHeavenBody() {}

	const LLVector3& getDirection()	const				{ return mDirection; }
	void setDirection(const LLVector3 &direction)		{ mDirection = direction; }
	void setAngularVelocity(const LLVector3 &ang_vel)	{ mAngularVelocity = ang_vel; }
	const LLVector3& getAngularVelocity() const			{ return mAngularVelocity; }

	const LLVector3& getDirectionCached() const			{ return mDirectionCached; }
	void renewDirection()								{ mDirectionCached = mDirection; }

	const LLColor3& getColorCached() const				{ return mColorCached; }
	void setColorCached(const LLColor3& c)				{ mColorCached = c; }
	const LLColor3& getColor() const					{ return mColor; }
	void setColor(const LLColor3& c)					{ mColor = c; }

	void renewColor()									{ mColorCached = mColor; }

	static F32 interpVal()								{ return sInterpVal; }
	static void setInterpVal(const F32 v)				{ sInterpVal = v; }

	LLColor3 getInterpColor() const
	{
		return sInterpVal * mColor + (1 - sInterpVal) * mColorCached;
	}

	const F32& getVisibility() const					{ return mVisibility; }
	void setVisibility(const F32 c = 1)					{ mVisibility = c; }

	BOOL isVisible() const								{ return mVisible; }
	void setVisible(const BOOL v)						{ mVisible = v; }

	const F32& getIntensity() const						{ return mIntensity; }
	void setIntensity(const F32 c)						{ mIntensity = c; }

	void setDiskRadius(const F32 radius)				{ mDiskRadius = radius; }
	F32	getDiskRadius()	const							{ return mDiskRadius; }

	void setDraw(const BOOL draw)						{ mDraw = draw; }
	BOOL getDraw() const								{ return mDraw; }

	const LLVector3& corner(const S32 n) const			{ return mQuadCorner[n]; }
	LLVector3& corner(const S32 n)						{ return mQuadCorner[n]; }
	const LLVector3* corners() const					{ return mQuadCorner; }
};

class LLCubeMap;

class LLVOSky : public LLStaticViewerObject
{
public:	
	enum
	{
		FACE_SIDE0,
		FACE_SIDE1,
		FACE_SIDE2,
		FACE_SIDE3,
		FACE_SIDE4,
		FACE_SIDE5,
		FACE_SUN, // was 6
		FACE_MOON, // was 7
		FACE_BLOOM, // was 8
		FACE_REFLECTION, // was 10
		FACE_COUNT
	};
	
	LLVOSky(const LLUUID &id, const LLPCode pcode, LLViewerRegion *regionp);

	// Initialize/delete data that's only inited once per class.
	void init();
	void initCubeMap();
	void initEmpty();
	
	void cleanupGL();
	void restoreGL();

	/*virtual*/ void idleUpdate(LLAgent &agent, const F64 &time);
	BOOL updateSky();
	
	// Graphical stuff for objects - maybe broken out into render class
	// later?
	/*virtual*/ void updateTextures();
	/*virtual*/ LLDrawable* createDrawable(LLPipeline *pipeline);
	/*virtual*/ BOOL		updateGeometry(LLDrawable *drawable);

	const LLHeavenBody& getSun() const						{ return mSun; }
	const LLHeavenBody& getMoon() const						{ return mMoon; }

	const LLVector3& getToSunLast() const					{ return mSun.getDirectionCached(); }
	const LLVector3& getToSun() const						{ return mSun.getDirection(); }
	const LLVector3& getToMoon() const						{ return mMoon.getDirection(); }
	const LLVector3& getToMoonLast() const					{ return mMoon.getDirectionCached(); }
	BOOL isSunUp() const									{ return mSun.getDirectionCached().mV[2] > -0.05f; }

    LLVector3 getLightDirection() const;
    LLColor3 getSunDiffuseColor() const;
    LLColor3 getMoonDiffuseColor() const;
    LLColor4 getSunAmbientColor() const;
    LLColor4 getMoonAmbientColor() const;
    LLColor4 getTotalAmbientColor() const;
	
	BOOL isSameFace(S32 idx, const LLFace* face) const { return mFace[idx] == face; }

	void initSunDirection(const LLVector3 &sun_dir, const LLVector3 &sun_ang_velocity);

    void setSunDirection(const LLVector3 &sun_dir, const LLVector3 &moon_dir);

	BOOL updateHeavenlyBodyGeometry(LLDrawable *drawable, const S32 side, LLHeavenBody& hb, const LLVector3 &up, const LLVector3 &right);
	void updateReflectionGeometry(LLDrawable *drawable, F32 H, const LLHeavenBody& HB);
	
	F32 getWorldScale() const							{ return mWorldScale; }
	void setWorldScale(const F32 s)						{ mWorldScale = s; }
	void updateFog(const F32 distance);

    void setFogRatio(const F32 fog_ratio)               { m_legacyAtmospherics.setFogRatio(fog_ratio); }
    F32  getFogRatio() const                            { return m_legacyAtmospherics.getFogRatio(); }

    LLColor4 getSkyFogColor() const                        { return m_legacyAtmospherics.getFogColor(); }
    LLColor4 getGLFogColor() const                      { return m_legacyAtmospherics.getGLFogColor(); }

    LLColor4U getFadeColor() const;

	void setCloudDensity(F32 cloud_density)				{ mCloudDensity = cloud_density; }
	void setWind ( const LLVector3& wind )				{ mWind = wind.length(); }

	const LLVector3 &getCameraPosAgent() const			{ return mCameraPosAgent; }
	LLVector3 getEarthCenter() const					{ return mEarthCenter; }

	LLCubeMap *getCubeMap() const						{ return mCubeMap; }
	S32 getDrawRefl() const								{ return mDrawRefl; }
	void setDrawRefl(const S32 r)						{ mDrawRefl = r; }
	BOOL isReflFace(const LLFace* face) const			{ return face == mFace[FACE_REFLECTION]; }
	LLFace* getReflFace() const							{ return mFace[FACE_REFLECTION]; }

	LLViewerTexture*	getSunTex() const					{ return mSunTexturep; }
	LLViewerTexture*	getMoonTex() const					{ return mMoonTexturep; }
	LLViewerTexture*	getBloomTex() const					{ return mBloomTexturep; }
	void forceSkyUpdate(void)							{ mForceUpdate = TRUE; }

public:
	LLFace	*mFace[FACE_COUNT];
	LLVector3	mBumpSunDir;

protected:
	~LLVOSky();

	void updateDirections(void);

	void initSkyTextureDirs(const S32 side, const S32 tile);
	void createSkyTexture(const S32 side, const S32 tile);

	LLPointer<LLViewerFetchedTexture> mSunTexturep;
	LLPointer<LLViewerFetchedTexture> mMoonTexturep;
	LLPointer<LLViewerFetchedTexture> mBloomTexturep;

	static S32			sResolution;
	static S32			sTileResX;
	static S32			sTileResY;
	LLSkyTex			mSkyTex[6];
	LLSkyTex			mShinyTex[6];
	LLHeavenBody		mSun;
	LLHeavenBody		mMoon;
	LLVector3			mSunDefaultPosition;
	LLVector3			mSunAngVel;
	F32					mAtmHeight;
	LLVector3			mEarthCenter;
	LLVector3			mCameraPosAgent;
	F32					mBrightnessScale;
	LLColor3			mBrightestPoint;
	F32					mBrightnessScaleNew;
	LLColor3			mBrightestPointNew;
	F32					mBrightnessScaleGuess;
	LLColor3			mBrightestPointGuess;
	BOOL				mWeatherChange;
	F32					mCloudDensity;
	F32					mWind;
	
	BOOL				mInitialized;
	BOOL				mForceUpdate;				//flag to force instantaneous update of cubemap
	LLVector3			mLastLightingDirection;
	LLColor3			mLastTotalAmbient;
	F32					mAmbientScale;
	LLColor3			mNightColorShift;
	F32					mInterpVal;
	F32					mWorldScale;

	LLPointer<LLCubeMap> mCubeMap;					// Cube map for the environment
	S32					 mDrawRefl;

	LLFrameTimer		mUpdateTimer;

	BOOL                mHeavenlyBodyUpdated ;

    LLAtmospherics      m_legacyAtmospherics;
};

#endif