/*==LICENSE==*

CyanWorlds.com Engine - MMOG client, server and tools
Copyright (C) 2011 Cyan Worlds, Inc.

This program 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 3 of the License, or
(at your option) any later version.

This program 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 this program. If not, see <http://www.gnu.org/licenses/>.

Additional permissions under GNU GPL version 3 section 7

If you modify this Program, or any covered work, by linking or
combining it with any of RAD Game Tools Bink SDK, Autodesk 3ds Max SDK,
NVIDIA PhysX SDK, Microsoft DirectX SDK, OpenSSL library, Independent
JPEG Group JPEG library, Microsoft Windows Media SDK, or Apple QuickTime SDK
(or a modified version of those libraries),
containing parts covered by the terms of the Bink SDK EULA, 3ds Max EULA,
PhysX SDK EULA, DirectX SDK EULA, OpenSSL and SSLeay licenses, IJG
JPEG Library README, Windows Media SDK EULA, or QuickTime SDK EULA, the
licensors of this Program grant you additional
permission to convey the resulting work. Corresponding Source for a
non-source form of such a combination shall include the source code for
the parts of OpenSSL and IJG JPEG Library used as well as that of the covered
work.

You can contact Cyan Worlds, Inc. by email legal@cyan.com
 or by snail mail at:
      Cyan Worlds, Inc.
      14617 N Newport Hwy
      Mead, WA   99021

*==LICENSE==*/
#include "hsTypes.h"
#include "hsInterp.h"
#include "../plTransform/hsAffineParts.h"
#include "hsColorRGBA.h"
#include "hsPoint2.h"

//
///////////////////////////////////////////////////////
// linear interpolation
///////////////////////////////////////////////////////
//
void hsInterp::LinInterp(hsScalar k1, hsScalar k2, hsScalar t, hsScalar* result)
{
	*result = k1 + t * (k2 - k1);
}

void hsInterp::LinInterp(const hsScalarTriple* k1, const hsScalarTriple* k2, hsScalar t, 
					  hsScalarTriple* result)
{
	if (t==0.0)
		*result = *k1;
	else
	if (t==1.0)
		*result = *k2;
	else
	{
		LinInterp(k1->fX, k2->fX, t, &result->fX);
		LinInterp(k1->fY, k2->fY, t, &result->fY);
		LinInterp(k1->fZ, k2->fZ, t, &result->fZ);
	}
}

void hsInterp::LinInterp(const hsColorRGBA* k1, const hsColorRGBA* k2, hsScalar t, 
					  hsColorRGBA* result, UInt32 flags)
{
	if (t==0.0)
	{
		// copy
		result->r = k1->r;
		result->g = k1->g;
		result->b = k1->b;
		if (!(flags & kIgnoreAlpha))
			result->a = k1->a;
		return;
	}

	if (t==1.0)
	{
		result->r = k2->r;
		result->g = k2->g;
		result->b = k2->b;
		if (!(flags & kIgnoreAlpha))
			result->a = k2->a;
		return;
	}
	
	LinInterp(k1->r, k2->r, t, &result->r);
	LinInterp(k1->g, k2->g, t, &result->g);
	LinInterp(k1->b, k2->b, t, &result->b);
	if (!(flags & kIgnoreAlpha))
		LinInterp(k1->a, k2->a, t, &result->a);
}

void hsInterp::LinInterp(const hsMatrix33* k1, const hsMatrix33* k2, hsScalar t, 
					  hsMatrix33* result, UInt32 flags)
{
	if (t==0.0)
	{
		// copy
		result->fMap[0][0] = k1->fMap[0][0];
		result->fMap[0][1] = k1->fMap[0][1];
		result->fMap[0][2] = k1->fMap[0][2];

		result->fMap[1][0] = k1->fMap[1][0];
		result->fMap[1][1] = k1->fMap[1][1];
		result->fMap[1][2] = k1->fMap[1][2];

		if (!(flags & kIgnoreLastMatRow))
		{
			result->fMap[2][0] = k1->fMap[2][0];
			result->fMap[2][1] = k1->fMap[2][1];
			result->fMap[2][2] = k1->fMap[2][2];
		}
		return;
	}
	if (t==1.0)
	{
		// copy
		result->fMap[0][0] = k2->fMap[0][0];
		result->fMap[0][1] = k2->fMap[0][1];
		result->fMap[0][2] = k2->fMap[0][2];

		result->fMap[1][0] = k2->fMap[1][0];
		result->fMap[1][1] = k2->fMap[1][1];
		result->fMap[1][2] = k2->fMap[1][2];

		if (!(flags & kIgnoreLastMatRow))
		{
			result->fMap[2][0] = k2->fMap[2][0];
			result->fMap[2][1] = k2->fMap[2][1];
			result->fMap[2][2] = k2->fMap[2][2];
		}
		return;
	}

	LinInterp(k1->fMap[0][0], k2->fMap[0][0], t, &result->fMap[0][0]);
	LinInterp(k1->fMap[0][1], k2->fMap[0][1], t, &result->fMap[0][1]);
	LinInterp(k1->fMap[0][2], k2->fMap[0][2], t, &result->fMap[0][2]);

	LinInterp(k1->fMap[1][0], k2->fMap[1][0], t, &result->fMap[1][0]);
	LinInterp(k1->fMap[1][1], k2->fMap[1][1], t, &result->fMap[1][1]);
	LinInterp(k1->fMap[1][2], k2->fMap[1][2], t, &result->fMap[1][2]);

	if (!(flags & kIgnoreLastMatRow))
	{
		LinInterp(k1->fMap[2][0], k2->fMap[2][0], t, &result->fMap[2][0]);
		LinInterp(k1->fMap[2][1], k2->fMap[2][1], t, &result->fMap[2][1]);
		LinInterp(k1->fMap[2][2], k2->fMap[2][2], t, &result->fMap[2][2]);
	}
}

//
//
void hsInterp::LinInterp(const hsMatrix44* mat1, const hsMatrix44* mat2, hsScalar t, 
					  hsMatrix44* out, UInt32 flags)
{
	if (flags == 0)
	{
		if( 0 == t )
		{
			*out = *mat1;
			return;
		}

		if( hsScalar1 == t )
		{
			*out = *mat2;
			return;
		}
	}

	if( flags & kIgnorePartsScale )
	{
		if (!(flags & kIgnorePartsRot))
		{
			// interp rotation with quats
			hsQuat q1, q2, qOut;
			q1.SetFromMatrix(mat1);
			q2.SetFromMatrix(mat2);
			LinInterp(&q1, &q2, t, &qOut);
			
			qOut.Normalize();
			qOut.MakeMatrix(out);
		}
		else
			out->Reset();
#if 1
		hsAssert(mat2->fMap[3][0]==0 && mat2->fMap[3][1]==0 && mat2->fMap[3][2]==0 && mat2->fMap[3][3]==1,
			"matrix prob?");
#else
		// copy 
		for(int i=0; i<3; i++)
			out->fMap[3][i] = mat2->fMap[3][i];
#endif
		
		if (!(flags & kIgnorePartsPos))
		{
			// interp translation
			hsPoint3 p1,p2,pOut;
			mat1->GetTranslate(&p1);
			mat2->GetTranslate(&p2);
			LinInterp(&p1, &p2, t, &pOut);
			out->SetTranslate(&pOut);
			out->NotIdentity();		// in case no rot
		}
	}
	else
	{
		// Complete decomp and parts interp

		gemAffineParts gemParts1, gemParts2;
		hsAffineParts parts1, parts2, partsOut;
	
		decomp_affine(mat1->fMap, &gemParts1); 
		AP_SET(parts1, gemParts1);

		decomp_affine(mat2->fMap, &gemParts2); 
		AP_SET(parts2, gemParts2);

		LinInterp(&parts1, &parts2, t, &partsOut, flags);	// flags will be parsed here

		partsOut.ComposeMatrix(out);
	}
}

void hsInterp::LinInterp(const hsQuat* k1, const hsQuat* k2, hsScalar t, hsQuat* result)
{
	if (t==0.0)
		*result = *k1;
	else
	if (t==1.0)
		*result = *k2;
	else
	{
		result->SetFromSlerp(*k1, *k2, t);
	}
}

void hsInterp::LinInterp(const hsScaleValue* k1, const hsScaleValue* k2, hsScalar t, 
					  hsScaleValue* result)
{
	LinInterp(&k1->fS, &k2->fS, t, &result->fS);	// Stretch rotation	
	LinInterp(&k1->fQ, &k2->fQ, t, &result->fQ);	// Stretch factor	
}

void hsInterp::LinInterp(const hsAffineParts* k1, const hsAffineParts* k2, hsScalar t, 
					  hsAffineParts* result, UInt32 flags)
{		
	if (t==0.0)
	{
		// copy
		if (!(flags & kIgnorePartsPos))
			result->fT = k1->fT;
		if (!(flags & kIgnorePartsRot))
			result->fQ = k1->fQ;
		if (!(flags & kIgnorePartsScale))
		{
			// same as preserveScale
			result->fU = k1->fU;
			result->fK = k1->fK;
		}
		result->fF = k1->fF;

		return;
	}
	
	if (flags & kPreservePartsScale)
	{
		result->fU = k1->fU;	// just copy scale from 1st key
		result->fK = k1->fK;
	}

	if (t==1.0)
	{
		// copy
		if (!(flags & kIgnorePartsPos))
			result->fT = k2->fT;
		if (!(flags & kIgnorePartsRot))
			result->fQ = k2->fQ;
		if (!(flags & (kIgnorePartsScale | kPreservePartsScale)))
		{
			result->fU = k2->fU;
			result->fK = k2->fK;
		}
		result->fF = k2->fF;

		return;
	}
	
	if(k1->fF!=k2->fF)
		hsStatusMessageF("WARNING: Inequality in affine parts flip value.");

//	hsAssert(k1->fF==k2->fF, "inequality in affine parts flip value");
	if (!(flags & kIgnorePartsPos))
		LinInterp(&k1->fT, &k2->fT, t, &result->fT);	// Translation
	if (!(flags & kIgnorePartsRot))
	{
		LinInterp(&k1->fQ, &k2->fQ, t, &result->fQ);	// Essential rotation	
	}
	
	if (!(flags & (kIgnorePartsScale | kPreservePartsScale)))
	{
		LinInterp(&k1->fU, &k2->fU, t, &result->fU);	// Stretch rotation	
		LinInterp(&k1->fK, &k2->fK, t, &result->fK);	// Stretch factor	
	}

#if 0
	if (!(flags & kIgnorePartsDet))
		LinInterp(k1->fF, k2->fF, t, &result->fF);	// Flip rot var
#else
	result->fF = k1->fF;
#endif
}

//
///////////////////////////////////////////////////////
// Key interpolation
///////////////////////////////////////////////////////
//

void hsInterp::BezScalarEval(const hsScalar value1, const hsScalar outTan,
							 const hsScalar value2, const hsScalar inTan,
							 const hsScalar t, const hsScalar tanScale, hsScalar *result)
{
#if 0
	// If the tangents were what you'd expect them to be... Hermite splines, than this code
	// would make sense. But no, Max likes to store them in a scaled form based on the
	// time of each frame. If we ever optimize this further, we could do the scaling on export,
	// but I need this to work right now before all the artists hate me too much.
	const hsScalar t2 = t * t;
	const hsScalar t3 = t2 * t;

	const hsScalar term1 = 2 * t3 - 3 * t2;

	*result = ((term1 + 1) * value1) +
		(-term1 * value2) +
		((t3 - 2 * t2 + 1) * outTan) +
		((t3 - t2) * inTan);
#else
	const hsScalar oneMinusT = (1.0f - t);
	const hsScalar tSq = t * t;
	const hsScalar oneMinusTSq = oneMinusT * oneMinusT;

	*result = (oneMinusT * oneMinusTSq * value1) +
		(3.f * t * oneMinusTSq * (value1 + outTan * tanScale)) +
		(3.f * tSq * oneMinusT * (value2 + inTan * tanScale)) +
		(tSq * t * value2);
#endif
}

void hsInterp::BezInterp(const hsBezPoint3Key* k1, const hsBezPoint3Key* k2, const hsScalar t, hsScalarTriple* result)
{
	hsScalar scale = (k2->fFrame - k1->fFrame) * MAX_TICKS_PER_FRAME / 3.f;
	BezScalarEval(k1->fValue.fX, k1->fOutTan.fX, k2->fValue.fX, k2->fInTan.fX, t, scale, &result->fX);
	BezScalarEval(k1->fValue.fY, k1->fOutTan.fY, k2->fValue.fY, k2->fInTan.fY, t, scale, &result->fY);
	BezScalarEval(k1->fValue.fZ, k1->fOutTan.fZ, k2->fValue.fZ, k2->fInTan.fZ, t, scale, &result->fZ);
}

void hsInterp::BezInterp(const hsBezScalarKey* k1, const hsBezScalarKey* k2, const hsScalar t, hsScalar* result)
{
	hsScalar scale = (k2->fFrame - k1->fFrame) * MAX_TICKS_PER_FRAME / 3.f;
	BezScalarEval(k1->fValue, k1->fOutTan, k2->fValue, k2->fInTan, t, scale, result);
}

void hsInterp::BezInterp(const hsBezScaleKey* k1, const hsBezScaleKey* k2, const hsScalar t, hsScaleValue* result)
{
	hsScalar scale = (k2->fFrame - k1->fFrame) * MAX_TICKS_PER_FRAME / 3.f;
	BezScalarEval(k1->fValue.fS.fX, k1->fOutTan.fX, k2->fValue.fS.fX, k2->fInTan.fX, t, scale, &result->fS.fX);
	BezScalarEval(k1->fValue.fS.fY, k1->fOutTan.fY, k2->fValue.fS.fY, k2->fInTan.fY, t, scale, &result->fS.fY);
	BezScalarEval(k1->fValue.fS.fZ, k1->fOutTan.fZ, k2->fValue.fS.fZ, k2->fInTan.fZ, t, scale, &result->fS.fZ);	

	// Slerp scale axis
	LinInterp(&k1->fValue.fQ, &k2->fValue.fQ, t, &result->fQ);
}

//
// Get an element from an array of unknown type
//
static inline hsKeyFrame* GetKey(Int32 i, void *keys, Int32 size)
{
	return (hsKeyFrame*) ((char*)keys + size * i);
}

//
// STATIC
// Given a list of keys, and a time, fills in the 2 boundary keys and 
// a fraction (p=0-1) indicating where the time falls between them.
// Returns the index of the first key which can be passed in as a hint (lastKeyIdx)
// for the next search.
//
void hsInterp::GetBoundaryKeyFrames(hsScalar time, UInt32 numKeys, void *keys, UInt32 size,
									hsKeyFrame **kF1, hsKeyFrame **kF2, UInt32 *lastKeyIdx, hsScalar *p, hsBool forwards)
{
	hsAssert(numKeys>1, "Must have more than 1 keyframe");
	int k1, k2;
	float frame = (time * MAX_FRAMES_PER_SEC);

	// boundary case, past end
	if (frame > GetKey(numKeys-1, keys, size)->fFrame)
	{
		k1=k2=numKeys-1;
		(*kF2) = GetKey(k1, keys, size);
		(*kF1) = (*kF2);
		*p = 0.0;
		goto ret;
	}

	hsKeyFrame *key1, *key2;
	// boundary case, before start
	if (frame < (key1=GetKey(0, keys, size))->fFrame)
	{
		k1=k2=0;
		(*kF1) = GetKey(k1, keys, size);
		(*kF2) = (*kF1);
		*p = 0.0;
		goto ret;
	}

	// prime loop
	int i;
	i = 1;
	if (*lastKeyIdx > 0 && *lastKeyIdx < numKeys - 1)
	{
		// new starting point for search
		if (forwards)
			key1 = GetKey(*lastKeyIdx, keys, size);
		else
			key2 = GetKey(*lastKeyIdx + 1, keys, size);

		i = *lastKeyIdx + 1;
	}
	else if (!forwards)
	{
		key2 = GetKey(1, keys, size);
	}

	// search pairs of keys
	int count;
	if (forwards)
	{
		for (count = 1; count <= numKeys; count++, i++)
		{
			if (i >= numKeys)
			{
				key1 = GetKey(0, keys, size);
				i = 1;
				count++;
			}
				
			key2 = GetKey(i, keys, size);
			if (frame <= key2->fFrame && frame >= key1->fFrame)
			{
				k2=i;
				k1=i-1;
				(*kF2) = key2;
				(*kF1) = key1;
				*p = (time - (*kF1)->fFrame / MAX_FRAMES_PER_SEC) / (((*kF2)->fFrame - (*kF1)->fFrame) / MAX_FRAMES_PER_SEC);
				goto ret;
			}
			key1=key2;
		}
	}
	else
	{
		for (count = 1; count <= numKeys; count++, i--)
		{
			if (i < 1)
			{
				i = numKeys - 1;
				key2 = GetKey(i, keys, size);
				count++;
			}
			
			key1 = GetKey(i - 1, keys, size);
			if (frame <= key2->fFrame && frame >= key1->fFrame)
			{
				k2 = i;
				k1 = i - 1;
				(*kF2) = key2;
				(*kF1) = key1;
				*p = (time - (*kF1)->fFrame / MAX_FRAMES_PER_SEC) / (((*kF2)->fFrame - (*kF1)->fFrame) / MAX_FRAMES_PER_SEC);
				goto ret;
			}
			key2=key1;
		}
	}		

ret:
;

#if 0
	char str[128];
	sprintf(str, "k1=%d, k2=%d, p=%f\n", k1, k2, *p);
	OutputDebugString(str);
#endif
	*lastKeyIdx = k1;
}