// $Id: gblend.cpp 751 2006-03-31 15:43:49Z alex $
/* @@tag:xara-cn@@ DO NOT MODIFY THIS LINE
================================XARAHEADERSTART===========================
 
               Xara LX, a vector drawing and manipulation program.
                    Copyright (C) 1993-2006 Xara Group Ltd.
       Copyright on certain contributions may be held in joint with their
              respective authors. See AUTHORS file for details.

LICENSE TO USE AND MODIFY SOFTWARE
----------------------------------

This file is part of Xara LX.

Xara LX is free software; you can redistribute it and/or modify it
under the terms of the GNU General Public License version 2 as published
by the Free Software Foundation.

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implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
See the GNU General Public License for more details.

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with Xara LX (see the file GPL in the root directory of the
distribution); if not, write to the Free Software Foundation, Inc., 51
Franklin St, Fifth Floor, Boston, MA  02110-1301 USA


ADDITIONAL RIGHTS
-----------------

Conditional upon your continuing compliance with the GNU General Public
License described above, Xara Group Ltd grants to you certain additional
rights. 

The additional rights are to use, modify, and distribute the software
together with the wxWidgets library, the wxXtra library, and the "CDraw"
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----------------

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MARKS
-----

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designs are registered or unregistered trademarks, design-marks, and/or
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      Xara Group Ltd, Gaddesden Place, Hemel Hempstead, HP2 6EX, UK.
                        http://www.xara.com/

=================================XARAHEADEREND============================
 */
// Gavin's blend code

/*
*/

#include "camtypes.h"

/////////////////////////////////////////////////////////////////////////////////////////////////
//
// GBlend.cpp
//
/////////////////////////////////////////////////////////////////////////////////////////////////

#include <math.h>
#include "gblend.h"

/////////////////////////////////////////////////////////////////////////////////////////////////
/////////////////////////////////////////////////////////////////////////////////////////////////

CONST BYTE PT_END = 0 ;

inline BOOL IsntEnd( BYTE Type )
{
	return Type!=PT_END ;
}

inline BOOL IsntMove( BYTE Type )
{
	return (Type & PT_MOVETO)!=PT_MOVETO ;
}

inline BOOL IsLine( BYTE Type )
{
	return (Type & PT_MOVETO)==PT_LINETO ;
}

inline BOOL IsCurve( BYTE Type )
{
	return (Type & PT_MOVETO)==PT_BEZIERTO ;
}

inline BOOL IsntCurve( BYTE Type )
{
	return (Type & PT_MOVETO)!=PT_BEZIERTO ;
}

/////////////////////////////////////////////////////////////////////////////////////////////////

inline UINT32 ScaledDiv( UINT32 N, UINT32 D )
{
	if (D == 0)
		return 1;
#if defined(__WXMSW__)
	UINT32 temp ;
	__asm {
		mov		eax,N
		xor		edx,edx
		shld	edx,eax,28
		shl		eax,28
		div		D
		mov		temp,eax
	}
	return temp ;
#else
	return UINT32((UINT64(N)<<28)/D);
#endif
}

inline INT32 ScaledMul( INT32 X, INT32 N )
{
//	return X*N/0x10000000 ;
#if defined(__WXMSW__)
	UINT32 temp ;
	__asm {
		mov		eax,X
		imul	N
		shrd	eax,edx,28
		mov		temp,eax
	}
	return temp ;
#else
	return INT32(INT64(X)*N>>28);
#endif
}

inline UINT32 length( POINT P0, POINT P1 )
{
#if defined(__WXMSW__)
	union {
		struct {
			DWORD lo ;
			DWORD hi ;
		} itemp ;
		double ftemp ;
	} val ;
	__asm {
		mov		eax,P1.x
		sub		eax,P0.x
		imul	eax
		mov		ebx,eax
		mov		ecx,edx
		mov		eax,P1.y
		sub		eax,P0.y
		imul	eax
		add		eax,ebx
		adc		edx,ecx
		mov		val.itemp.lo,eax
		mov		val.itemp.hi,edx
		fild	val.ftemp
		fsqrt
		fistp	val.itemp.lo
	}
	return val.itemp.lo ;
#else
	return (UINT32)sqrt( double(P1.x-P0.x)*(P1.x-P0.x)+double(P1.y-P0.y)*(P1.y-P0.y) ) ;
#endif
}

/////////////////////////////////////////////////////////////////////////////////////////////////
/////////////////////////////////////////////////////////////////////////////////////////////////

void GBlend::Define(
		PPOINT	Src0Points,
		PBYTE	Src0Types,
		UINT32	Src0Length,
		PPOINT	Src1Points,
		PBYTE	Src1Types,
		UINT32	Src1Length,
		BOOL	Flag,
		UINT32	pFlatness,
		PUINT32	Buffer,
		UINT32	BufferLength
	)
{
	S0Points	= Src0Points ;
	S0Types		= Src0Types ;
	S0Length	= Src0Length ;
	S1Points	= Src1Points ;
	S1Types		= Src1Types ;
	S1Length	= Src1Length ;
	Is1to1		= Flag ;
	Flatness	= pFlatness*27/2 ;
	CalcPathLengths(
		S0Points, S0Types, S0Length,
		LengthPtr0 = Buffer,
		BufferLength,
		EndLengthPtr0
	) ;
	CalcPathLengths(
		S1Points, S1Types, S1Length,
		LengthPtr1 = EndLengthPtr0,
		BufferLength-(EndLengthPtr0-LengthPtr0),
		EndLengthPtr1
	) ;
	Is1to1 = Is1to1 && (EndLengthPtr0-LengthPtr0)==(EndLengthPtr1-LengthPtr1) ;
}

UINT32 GBlend::Blend( double pRatio, PPOINT DPoints, PBYTE DTypes, INT32 DLength )
{
	Ratio		= (INT32) (pRatio*0x10000000) ;
	OPoints		= DPoints ;
	OTypes		= DTypes ;
	OLength		= DLength ;
	IPoints0	= S0Points ;
	ITypes0		= S0Types ;
	ILength0	= S0Length ;
	IPoints1	= S1Points ;
	ITypes1		= S1Types ;
	ILength1	= S1Length ;
	LPtr0		= LengthPtr0 ;
	LPtr1		= LengthPtr1 ;
	P00 = *IPoints0++ ; Type0 = *ITypes0++ ; ILength0-- ;
	P10 = *IPoints1++ ; Type1 = *ITypes1++ ; ILength1-- ;
	if ( !BlendPoint( PT_MOVETO, P00, P10 ) )
		return FALSE ;
	Length0 = 0 ; ReadPathStart0() ;
	Length1 = 0 ; ReadPathStart1() ;
	if ( Is1to1 )
	{
		if ( !BlendNtoN() )
			return 0 ;
	}
	else
	{
		if ( !BlendMtoN() )
			return 0 ;
	}
	return OTypes-DTypes ;
}

/////////////////////////////////////////////////////////////////////////////////////////////////

BOOL GBlend::CalcPathLengths(
		PPOINT	Points,
		PBYTE	Types,
		UINT32	Length,
		PUINT32	Buffer,
		UINT32	BufferLength,
		PUINT32 &BufferEnd
	)
{
	UINT32 TotalLength = 0 ;
	BufferEnd = Buffer ;
    UINT32 i = 1 ;
    while ( i<Length )
    {
		if ( IsLine(Types[i]) )
		{
			*BufferEnd = length( Points[i-1],Points[i] ) ;
			i++ ;
		}
		else /* Curve */
		{
			*BufferEnd = BezierLength( Points[i-1],Points[i],Points[i+1],Points[i+2] ) ;
			i+=3 ;
    	}
		TotalLength += *BufferEnd++ ;
    }
	PUINT32 P = Buffer ;
	UINT32 Total = 0 ;
	while ( P<BufferEnd )
	{
		*P = ScaledDiv( *P, TotalLength ) ;
		Total += *P++ ;
	}
	if ( Total != 0x10000000 )
	{
		while ( *(--P)+0x10000000 <= Total )
		{ }
		*P -= Total-0x10000000 ;
	}
	return TRUE ;
}

/////////////////////////////////////////////////////////////////////////////////////////////////

BOOL GBlend::BlendNtoN()
{
	while ( IsntEnd(Type0) || IsntEnd(Type1) )
		if ( !Blend1to1() )
			return FALSE ;
	return TRUE ;
}

BOOL GBlend::BlendMtoN()
{
	UINT32 t ;
	while ( IsntEnd(Type0) || IsntEnd(Type1) )
	{
		if ( LPtr1==EndLengthPtr1-1 )
			MatchLast( LPtr0, EndLengthPtr0, *LPtr1+Length1-Length0, Match0, Total0 ) ;
		else
			Match    ( LPtr0, EndLengthPtr0, *LPtr1+Length1-Length0, Match0, Total0 ) ;
		if ( LPtr0==EndLengthPtr0-1 )
			MatchLast( LPtr1, EndLengthPtr1, *LPtr0+Length0-Length1, Match1, Total1 ) ;
		else
			Match    ( LPtr1, EndLengthPtr1, *LPtr0+Length0-Length1, Match1, Total1 ) ;
		if ( abs(Match0)<abs(Match1) )
		{
			if ( Total0!=1 )
			{
				Match0 += *LPtr1+Length1-Length0 ;
				if ( IsntCurve(Type1) )
				{
					P11.x = (2*P10.x+P13.x)/3 ; P12.x = (P10.x+2*P13.x)/3 ;
					P11.y = (2*P10.y+P13.y)/3 ; P12.y = (P10.y+2*P13.y)/3 ;
				}
				for ( t=2 ; t<=Total0 ; t++ )
				{
					if ( IsCurve(Type0) || IsCurve(Type1) )
					{
						if ( IsntCurve(Type0) )
						{
							P01.x = (2*P00.x+P03.x)/3 ; P02.x = (P00.x+2*P03.x)/3 ;
							P01.y = (2*P00.y+P03.y)/3 ; P02.y = (P00.y+2*P03.y)/3 ;
						}
						Split( P10,P11,P12,P13, *LPtr0,Match0 ) ;
						if ( !BlendCurve( P01,P02,P03, L1,L2,M ) )
							return FALSE ;
						P10 = M ;
						P11 = R1 ;
						P12 = R2 ;
					}
					else
					{
						P10.x += MulDiv(P13.x-P10.x,*LPtr0,Match0) ;
						P10.y += MulDiv(P13.y-P10.y,*LPtr0,Match0) ;
						if ( !BlendPoint( PT_LINETO, P03, P10 ) )
							return FALSE ;
					}
					P00 = P03 ;
					Match0 -= *LPtr0 ;
					ReadPath0() ;
				}
			}
		}
		else
		{
			if ( Total1!=1 )
			{
				Match1 += *LPtr0+Length0-Length1 ;
				if ( IsntCurve(Type0) )
				{
					P01.x = (2*P00.x+P03.x)/3 ; P02.x = (P00.x+2*P03.x)/3 ;
					P01.y = (2*P00.y+P03.y)/3 ; P02.y = (P00.y+2*P03.y)/3 ;
				}
				for ( t=2 ; t<=Total1 ; t++ )
				{
					if ( IsCurve(Type0) || IsCurve(Type1) )
					{
						if ( IsntCurve(Type1) )
						{
							P11.x = (2*P10.x+P13.x)/3 ; P12.x = (P10.x+2*P13.x)/3 ;
							P11.y = (2*P10.y+P13.y)/3 ; P12.y = (P10.y+2*P13.y)/3 ;
						}
						Split( P00,P01,P02,P03, *LPtr1,Match1 ) ;
						if ( !BlendCurve( L1,L2,M, P11,P12,P13 ) )
							return FALSE ;
						P00 = M ;
						P01 = R1 ;
						P02 = R2 ;
					}
					else
					{
						P00.x += MulDiv(P03.x-P00.x,*LPtr1,Match1) ;
						P00.y += MulDiv(P03.y-P00.y,*LPtr1,Match1) ;
						if ( !BlendPoint( PT_LINETO, P00, P13 ) )
							return FALSE ;
					}
					P10 = P13 ;
					Match1 -= *LPtr1 ;
					ReadPath1()	;
				}
			}
		}
		if ( !Blend1to1() )
			return FALSE ;
	} /* while */
	return TRUE ;
}

BOOL GBlend::Blend1to1()
{
	if ( IsCurve(Type0) || IsCurve(Type1) )
	{
		if ( IsntCurve(Type0) )
		{
			P01.x = (2*P00.x+P03.x)/3 ; P02.x = (P00.x+2*P03.x)/3 ;
			P01.y = (2*P00.y+P03.y)/3 ; P02.y = (P00.y+2*P03.y)/3 ;
		}
		if ( IsntCurve(Type1) )
		{
			P11.x = (2*P10.x+P13.x)/3 ; P12.x = (P10.x+2*P13.x)/3 ;
			P11.y = (2*P10.y+P13.y)/3 ; P12.y = (P10.y+2*P13.y)/3 ;
		}
		if ( !BlendCurve( P01,P02,P03, P11,P12,P13 ) )
			return FALSE ;
	}
	else
		if ( !BlendPoint( PT_LINETO, P03, P13 ) )
			return FALSE ;
	P00 = P03 ; ReadPath0() ;
	P10 = P13 ;	ReadPath1() ;
	return TRUE ;
}

BOOL GBlend::BlendPoint( BYTE Type, POINT P0, POINT P1 )
{
	if ( --OLength<0 )
		return FALSE ;
	*OTypes++ = Type ;
	OPoints->x = P0.x+ScaledMul(Ratio,P1.x-P0.x) ;
	OPoints->y = P0.y+ScaledMul(Ratio,P1.y-P0.y) ;
	OPoints++ ;
	return TRUE ;
}

BOOL GBlend::BlendCurve( POINT P01,POINT P02,POINT P03, POINT P11,POINT P12,POINT P13 )
{
	return BlendPoint( PT_BEZIERTO, P01, P11 ) &&
		   BlendPoint( PT_BEZIERTO, P02, P12 ) &&
		   BlendPoint( PT_BEZIERTO, P03, P13 ) ;
}

void GBlend::Match( PUINT32 Ptr, PUINT32 EndPtr, UINT32 Length, INT32 &Match, UINT32 &Total )
{
	Match = -(INT32)Length ;
	Total = 0 ;
	if ( Ptr<EndPtr )
	{
		Match += *Ptr++ ;
		Total++ ;
		while ( Ptr<EndPtr-1 && abs((INT32)Match)>abs((INT32)(*Ptr+Match)) )
		{
			Match += *Ptr++ ;
			Total++ ;
		}
	}
}

void GBlend::MatchLast( PUINT32 Ptr, PUINT32 EndPtr, UINT32 Length, INT32 &Match, UINT32 &Total )
{
	Match = -(INT32)Length ;
	Total = 0 ;
	while ( Ptr<EndPtr )
	{
		Match += *Ptr++ ;
		Total++ ;
	}
}

void GBlend::Split( POINT P0,POINT P1,POINT P2,POINT P3, INT32 N,UINT32 D )
{
	L1.x = P0.x+MulDiv(P1.x-P0.x,N,D) ; L1.y = P0.y+MulDiv(P1.y-P0.y,N,D) ;
	 M.x = P1.x+MulDiv(P2.x-P1.x,N,D) ;  M.y = P1.y+MulDiv(P2.y-P1.y,N,D) ;
	R2.x = P2.x+MulDiv(P3.x-P2.x,N,D) ; R2.y = P2.y+MulDiv(P3.y-P2.y,N,D) ;
	L2.x = L1.x+MulDiv( M.x-L1.x,N,D) ; L2.y = L1.y+MulDiv( M.y-L1.y,N,D) ;
	R1.x =  M.x+MulDiv(R2.x- M.x,N,D) ; R1.y =  M.y+MulDiv(R2.y- M.y,N,D) ;
	 M.x = L2.x+MulDiv(R1.x-L2.x,N,D) ;  M.y = L2.y+MulDiv(R1.y-L2.y,N,D) ;
}

/////////////////////////////////////////////////////////////////////////////////////////////////

void GBlend::ReadPath0()
{
	Length0 += *LPtr0++ ;
	ReadPathStart0() ;
}

void GBlend::ReadPathStart0()
{
	if ( ILength0==0 )
		Type0 = PT_END ;
	else if ( IsLine(Type0=*ITypes0) )
	{
		ITypes0++ ;
		P03 = *IPoints0++ ;
		ILength0-- ;
	}
	else /* Curve */
	{
		ITypes0+=3 ;
		P01 = *IPoints0++ ;
		P02 = *IPoints0++ ;
		P03 = *IPoints0++ ;
		ILength0-=3 ;
	}
}

void GBlend::ReadPath1()
{
	Length1 += *LPtr1++ ;
	ReadPathStart1() ;
}

void GBlend::ReadPathStart1()
{
	if ( ILength1==0 )
		Type1 = PT_END ;
	else if ( IsLine(Type1=*ITypes1) )
	{
		ITypes1++ ;
		P13 = *IPoints1++ ;
		ILength1-- ;
	}
	else /* Curve */
	{
		ITypes1+=3 ;
		P11 = *IPoints1++ ;
		P12 = *IPoints1++ ;
		P13 = *IPoints1++ ;
		ILength1-=3 ;
	}
}

/////////////////////////////////////////////////////////////////////////////////////////////////

INT32 GBlend::BezierLength( POINT P0, POINT P1, POINT P2, POINT P3 )
{
	UINT32 dx,dy ;
	dx = abs(P1.x*3 - P0.x*2 - P3.x) ;
	dy = abs(P1.y*3 - P0.y*2 - P3.y) ;
	if ( (dx>=dy ? 3*dx+dy : dx+3*dy) > Flatness )
    	return FlattenSplit(P0,P1,P2,P3) ;
	dx = abs(P2.x*3 - P0.x - P3.x*2) ;
	dy = abs(P2.y*3 - P0.y - P3.y*2) ;
	if ( (dx>=dy ? 3*dx+dy : dx+3*dy) > Flatness )
    	return FlattenSplit(P0,P1,P2,P3) ;
	return length(P0,P3) ;
}


INT32 GBlend::FlattenSplit( POINT P0, POINT P1, POINT P2, POINT P3 )
{
	POINT L1, L2, M, R1, R2 ;
	L1.x = (P0.x + P1.x)/2;
	L1.y = (P0.y + P1.y)/2;
	L2.x = (P0.x + 2*P1.x + P2.x)/4;
	L2.y = (P0.y + 2*P1.y + P2.y)/4;
	 M.x = (P0.x + 3*P1.x + 3*P2.x + P3.x)/8;
	 M.y = (P0.y + 3*P1.y + 3*P2.y + P3.y)/8;
	R1.x = (P1.x + 2*P2.x + P3.x)/4;
	R1.y = (P1.y + 2*P2.y + P3.y)/4;
	R2.x = (P2.x + P3.x)/2;
	R2.y = (P2.y + P3.y)/2;
    return BezierLength(P0, L1, L2, M) + BezierLength(M, R1, R2, P3) ;
}

/////////////////////////////////////////////////////////////////////////////////////////////////