gblend.cpp

Go to the documentation of this file.

// $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.

Xara LX and its component source files are 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 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"
library and any other such library that any version of Xara LX relased
by Xara Group Ltd requires in order to compile and execute, including
the static linking of that library to XaraLX. In the case of the
"CDraw" library, you may satisfy obligation under the GNU General Public
License to provide source code by providing a binary copy of the library
concerned and a copy of the license accompanying it.

Nothing in this section restricts any of the rights you have under
the GNU General Public License.


SCOPE OF LICENSE
----------------

This license applies to this program (XaraLX) and its constituent source
files only, and does not necessarily apply to other Xara products which may
in part share the same code base, and are subject to their own licensing
terms.

This license does not apply to files in the wxXtra directory, which
are built into a separate library, and are subject to the wxWindows
license contained within that directory in the file "WXXTRA-LICENSE".

This license does not apply to the binary libraries (if any) within
the "libs" directory, which are subject to a separate license contained
within that directory in the file "LIBS-LICENSE".


ARRANGEMENTS FOR CONTRIBUTION OF MODIFICATIONS
----------------------------------------------

Subject to the terms of the GNU Public License (see above), you are
free to do whatever you like with your modifications. However, you may
(at your option) wish contribute them to Xara's source tree. You can
find details of how to do this at:
  http://www.xaraxtreme.org/developers/

Prior to contributing your modifications, you will need to complete our
contributor agreement. This can be found at:
  http://www.xaraxtreme.org/developers/contribute/

Please note that Xara will not accept modifications which modify any of
the text between the start and end of this header (marked
XARAHEADERSTART and XARAHEADEREND).


MARKS
-----

Xara, Xara LX, Xara X, Xara X/Xtreme, Xara Xtreme, the Xtreme and Xara
designs are registered or unregistered trademarks, design-marks, and/or
service marks of Xara Group Ltd. All rights in these marks are reserved.


      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) ;
}

---