fuzzclip.cpp

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// $Id: fuzzclip.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
----------------------------------

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 */
// This is a Gavin File that contains the code to clip paths before rendering them to allow
// much higher levels of zoom.

/*
*/

#include "camtypes.h"
#include "fuzzclip.h"
//#include <limits.h>
//#include <afxwin.h>
//#include <math.h>


struct GRECT {
    INT32 lx ;
    INT32 ly ;
    INT32 hx ;
    INT32 hy ;
} ;

/*
    bl - bottom left
    br - bottom right
    tl - top left
    tr - top right
    10 - bl+br
    11 - bl+tl
    12 - br+tr
    13 - br+bl
    14 - tl+tr
    15 - tl+bl
    16 - tr+br
    17 - tr+tl
    oo - ignore line
    xx - split line
    pp - plot start and end
    ee - plot end only
*/

#define oo 00
#define bl 01
#define br 02
#define tl 03
#define tr 04
#define pp 05
#define ee 06
#define xx 07

static CONST BYTE CaseTable[25][25] = {
//   BL    BC    BR                  CL    CC    CR                  TL    TC    TR
    {oo,bl,bl,bl,bl, bl,oo,bl,bl,10, bl,bl,xx,xx,xx, bl,bl,xx,xx,xx, bl,11,xx,xx,xx},   // BL
    {oo,oo,oo,oo,oo, bl,oo,oo,oo,br, bl,bl,xx,xx,xx, bl,bl,xx,xx,xx, bl,11,xx,xx,xx},
    {oo,oo,oo,oo,oo, bl,oo,oo,oo,br, bl,xx,xx,xx,br, xx,xx,xx,xx,xx, xx,xx,xx,xx,xx},   // BC
    {oo,oo,oo,oo,oo, bl,oo,oo,oo,br, xx,xx,xx,br,br, xx,xx,xx,br,br, xx,xx,xx,12,br},
    {br,br,br,br,oo, 13,br,br,oo,br, xx,xx,xx,br,br, xx,xx,xx,br,br, xx,xx,xx,12,br},   // BR

    {oo,bl,bl,bl,bl, oo,oo,bl,bl,10, oo,oo,xx,xx,xx, oo,oo,xx,xx,xx, oo,tl,xx,xx,xx},
    {oo,bl,bl,bl,bl, bl,oo,bl,bl,10, bl,bl,pp,pp,xx, bl,bl,pp,pp,xx, bl,11,xx,xx,xx},
    {oo,oo,oo,oo,oo, bl,oo,oo,oo,br, xx,pp,pp,pp,xx, xx,pp,pp,pp,xx, xx,xx,xx,xx,xx},
    {br,br,br,br,oo, 13,br,br,oo,br, xx,pp,pp,br,br, xx,pp,pp,br,br, xx,xx,xx,12,br},
    {br,br,br,br,oo, 13,br,br,oo,oo, xx,xx,xx,oo,oo, xx,xx,xx,oo,oo, xx,xx,xx,tr,oo},

    {oo,bl,bl,xx,xx, oo,oo,xx,xx,xx, oo,oo,xx,xx,xx, oo,oo,xx,xx,xx, oo,tl,tl,xx,xx},   // CL
    {oo,bl,xx,xx,xx, oo,oo,pp,pp,xx, oo,oo,pp,pp,xx, oo,oo,pp,pp,xx, oo,tl,xx,xx,xx},
    {xx,xx,xx,xx,xx, xx,ee,ee,ee,xx, xx,ee,ee,ee,xx, xx,ee,ee,ee,xx, xx,xx,xx,xx,xx},   // CC
    {xx,xx,xx,br,oo, xx,pp,pp,oo,oo, xx,pp,pp,oo,oo, xx,pp,pp,oo,oo, xx,xx,xx,tr,oo},
    {xx,xx,br,br,oo, xx,xx,xx,oo,oo, xx,xx,xx,oo,oo, xx,xx,xx,oo,oo, xx,xx,tr,tr,oo},   // CR

    {oo,bl,xx,xx,xx, oo,oo,xx,xx,xx, oo,oo,xx,xx,xx, oo,oo,tl,tl,14, oo,tl,tl,tl,tl},
    {tl,15,xx,xx,xx, tl,tl,pp,pp,xx, tl,tl,pp,pp,xx, tl,oo,tl,tl,14, oo,tl,tl,tl,tl},
    {xx,xx,xx,xx,xx, xx,pp,pp,pp,xx, xx,pp,pp,pp,xx, tl,oo,oo,oo,tr, oo,oo,oo,oo,oo},
    {xx,xx,xx,16,tr, xx,pp,pp,tr,tr, xx,pp,pp,tr,tr, 17,tr,tr,oo,tr, tr,tr,tr,tr,oo},
    {xx,xx,xx,br,oo, xx,xx,xx,oo,oo, xx,xx,xx,oo,oo, 17,tr,tr,oo,oo, tr,tr,tr,tr,oo},

    {tl,15,xx,xx,xx, tl,tl,xx,xx,xx, tl,tl,xx,xx,xx, tl,oo,tl,tl,14, oo,tl,tl,tl,tl},   // TL
    {tl,15,xx,xx,xx, tl,tl,xx,xx,xx, tl,tl,xx,xx,xx, tl,oo,oo,oo,tr, oo,oo,oo,oo,oo},
    {xx,xx,xx,xx,xx, xx,xx,xx,xx,xx, tl,xx,xx,xx,tr, tl,oo,oo,oo,tr, oo,oo,oo,oo,oo},   // TC
    {xx,xx,xx,16,tr, xx,xx,xx,tr,tr, xx,xx,xx,tr,tr, tl,oo,oo,oo,tr, oo,oo,oo,oo,oo},
    {xx,xx,xx,16,tr, xx,xx,xx,tr,tr, xx,xx,xx,tr,tr, 17,tr,tr,oo,tr, tr,tr,tr,tr,oo}    // TR
} ;

//
// Define regions :
//
// *****  *++++  ++++*  +++++  +++++  +++++  +++++  +++++  +++++  +++++
// +++++  *++++  ++++*  +++++  +***+  +*+++  +++*+  +++++  ++*++  +++++
// +++++  *++++  ++++*  +++++  +++++  +*+++  +++*+  +++++  ++*++  +***+
// +++++  *++++  ++++*  +++++  +++++  +*+++  +++*+  +***+  ++*++  +++++
// +++++  *++++  ++++*  *****  +++++  +++++  +++++  +++++  +++++  +++++
//
static CONST DWORD Region[25] = {
    0x003,0x001,0x001,0x001,0x005,
    0x002,0x030,0x110,0x050,0x004,
    0x002,0x220,0x300,0x240,0x004,
    0x002,0x0a0,0x180,0x0c0,0x004,
    0x00a,0x008,0x008,0x008,0x00c
} ;

static  INT32   LastSector ;

static  GRECT   *IRect ;
static  GRECT   *ORect ;

static  POINT   LastPoint ;

static  PPOINT  OPoints ;
static  PBYTE   OTypes ;
static  size_t  OMaxLength ;
static  size_t  OLength ;
static  BOOL    OFirstPoint ;

static  UINT32  Index ;             // Position within source path.
static  UINT32  LastIndex ;         // Position within source path for last output point.
static  BOOL    SameLine ;          // Last two output points are for the same path.


inline BOOL IsMove( CONST BYTE Type )
{
    return (Type & PT_MOVETO)==PT_MOVETO ;
}

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

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

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

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

//
// SameLine indicates that two points of the current line have been plotted. A third point can
// overwrite the second.
//
void GenLine( INT32 X, INT32 Y, BOOL Merge=TRUE )
{
    if ( OFirstPoint )
    {
        OFirstPoint = FALSE ;
        if ( ++OLength > OMaxLength )
            throw 1 ;
        *OTypes++ = PT_MOVETO ;
        OPoints->x = X ;
        OPoints->y = Y ;
        OPoints++ ;
        SameLine = FALSE ;
        LastIndex = Merge?Index:INT32_MAX ;
    }
    else if ( Merge && SameLine && LastIndex==Index )
    {
        (OPoints-1)->x = X ;
        (OPoints-1)->y = Y ;
    }
    else if ( (OPoints-1)->x != X ||
              (OPoints-1)->y != Y )
    {
        if ( ++OLength > OMaxLength )
            throw 1 ;
        *OTypes++ = PT_LINETO ;
        OPoints->x = X ;
        OPoints->y = Y ;
        OPoints++ ;
        SameLine = Merge && (LastIndex==Index) ;
        LastIndex = Merge?Index:INT32_MAX ;
    }
}


void GenCurve( POINT &P1, POINT &P2, POINT &P3 )
{
    if ( (OLength+=3) > OMaxLength )
        throw 1 ;
    *OTypes++ = PT_BEZIERTO ; *OPoints++ = P1 ;
    *OTypes++ = PT_BEZIERTO ; *OPoints++ = P2 ;
    *OTypes++ = PT_BEZIERTO ; *OPoints++ = P3 ;
    SameLine = FALSE ;
    LastIndex = INT32_MAX ;
}


inline void GenLine( POINT &P, BOOL F=TRUE ) { GenLine( P.x,P.y,F ) ; } ;


inline void GenLineToBelowLeft () { GenLine( IRect->lx,IRect->ly,FALSE ) ; } ;
inline void GenLineToBelowRight() { GenLine( IRect->hx,IRect->ly,FALSE ) ; } ;
inline void GenLineToAboveLeft () { GenLine( IRect->lx,IRect->hy,FALSE ) ; } ;
inline void GenLineToAboveRight() { GenLine( IRect->hx,IRect->hy,FALSE ) ; } ;

//
// GetSector(P) returns the sector containing the point P according to the following :
//
//
//   ORect.lx   IRect.hx
//       |         |
//       |IRect.lx | ORect.hx
//       |    |    |    |
//       |    |    |    |
//    20 | 21 | 22 | 23 | 24
//  -----+----+----+----+-----  ORect.hy
//    15 | 16 | 17 | 18 | 19
//  -----+----+----+----+-----  IRect.hy
//    10 | 11 | 12 | 13 | 14
//  -----+----+----+----+-----  IRect.ly
//    05 | 06 | 07 | 08 | 09
//  -----+----+----+----+-----  ORect.ly
//    00 | 01 | 02 | 03 | 04
//       |    |    |    |
//
//
INT32 GetSector( POINT &P )
{
    INT32 Sector = 12 ;
    if ( P.x < IRect->lx )
        if ( P.x < ORect->lx )
            Sector -= 2 ;
        else
            Sector-- ;
    else if ( P.x > IRect->hx )
        if ( P.x > ORect->hx )
            Sector += 2 ;
        else
            Sector++ ;
    if ( P.y < IRect->ly )
        if ( P.y < ORect->ly )
            Sector -= 2*5 ;
        else
            Sector -= 5 ;
    else if ( P.y > IRect->hy )
        if ( P.y > ORect->hy )
            Sector += 2*5 ;
        else
            Sector += 5 ;
    return Sector ;
}


void ClipLine( POINT &Start, POINT &End )
{
    INT32 ThisSector = GetSector( End ) ;
    switch ( CaseTable[(INT32)LastSector][(INT32)ThisSector] )
    {
    case 01 : GenLineToBelowLeft()  ; break ;
    case 02 : GenLineToBelowRight() ; break ;
    case 03 : GenLineToAboveLeft()  ; break ;
    case 04 : GenLineToAboveRight() ; break ;
    case 05 : GenLine(Start)        ;
              GenLine(End)          ; break ;
    case 06 : if ( OFirstPoint )
                  GenLine(Start) ;
              GenLine(End)          ; break ;
    case 07 :
        POINT Middle ;
        Middle.x = (Start.x+End.x) >> 1 ;
        Middle.y = (Start.y+End.y) >> 1 ;
        ClipLine( Start,Middle ) ;
        ClipLine( Middle,End ) ;
        return ;
    case 10 : GenLineToBelowLeft()  ; GenLineToBelowRight() ; break ;
    case 11 : GenLineToBelowLeft()  ; GenLineToAboveLeft()  ; break ;
    case 12 : GenLineToBelowRight() ; GenLineToAboveRight() ; break ;
    case 13 : GenLineToBelowRight() ; GenLineToBelowLeft()  ; break ;
    case 14 : GenLineToAboveLeft()  ; GenLineToAboveRight() ; break ;
    case 15 : GenLineToAboveLeft()  ; GenLineToBelowLeft()  ; break ;
    case 16 : GenLineToAboveRight() ; GenLineToBelowRight() ; break ;
    case 17 : GenLineToAboveRight() ; GenLineToAboveLeft()  ; break ;
    }
    LastSector = ThisSector ;
}


void SplitCurve( POINT &P0, POINT &P1, POINT &P2, POINT &P3 ) ;


void ClipCurve( POINT &C0, POINT &C1, POINT &C2, POINT &C3 )
{
    INT32 C1Sector  = GetSector( C1 ) ;
    INT32 C2Sector  = GetSector( C2 ) ;
    INT32 ThisSector    = GetSector( C3 ) ;
//  if ( ( ( C1Sector==LastSector || C1Sector==ThisSector ) &&
//         ( C2Sector==LastSector || C2Sector==ThisSector ) ) ||
//       ( Region[LastSector] & Region[C1Sector] & Region[C2Sector] & Region[ThisSector] ) )
    INT32 RegionUnion = Region[LastSector] & Region[C1Sector] & Region[C2Sector] & Region[ThisSector];
    if ( ( RegionUnion & 0x0ff ) ||
         ( (RegionUnion & 0x300) && (LastSector!=ThisSector || LastSector==12) ) ||
         ( (C1Sector==LastSector || C1Sector==ThisSector) && (C2Sector==LastSector || C2Sector==ThisSector) ) )
    {
        switch ( CaseTable[(INT32)LastSector][(INT32)ThisSector] )
        {
        case 01 : GenLineToBelowLeft()  ; break ;
        case 02 : GenLineToBelowRight() ; break ;
        case 03 : GenLineToAboveLeft()  ; break ;
        case 04 : GenLineToAboveRight() ; break ;
        case 05 : GenLine(C0,FALSE) ;
                  GenCurve(C1,C2,C3)    ; break ;
        case 06 : if ( OFirstPoint )
                      GenLine(C0,FALSE) ;
                  GenCurve(C1,C2,C3)    ; break ;
        case 07 : SplitCurve(C0,C1,C2,C3) ; return ;
        case 10 : GenLineToBelowLeft()  ; GenLineToBelowRight() ; break ;
        case 11 : GenLineToBelowLeft()  ; GenLineToAboveLeft()  ; break ;
        case 12 : GenLineToBelowRight() ; GenLineToAboveRight() ; break ;
        case 13 : GenLineToBelowRight() ; GenLineToBelowLeft()  ; break ;
        case 14 : GenLineToAboveLeft()  ; GenLineToAboveRight() ; break ;
        case 15 : GenLineToAboveLeft()  ; GenLineToBelowLeft()  ; break ;
        case 16 : GenLineToAboveRight() ; GenLineToBelowRight() ; break ;
        case 17 : GenLineToAboveRight() ; GenLineToAboveLeft()  ; break ;
        }
        LastSector = ThisSector ;
    }
    else
        SplitCurve(C0,C1,C2,C3) ;
}


void SplitCurve( 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;
    ClipCurve( P0,L1,L2, M ) ;
    ClipCurve(  M,R1,R2,P3 ) ;
}


size_t FuzzyClip(
        PPOINT  IPoints,
        PBYTE   ITypes,
        size_t  ILength,
        BOOL    IsClosed,
        RECT    *InnerRect,
        RECT    *OuterRect,
        PPOINT  pOPoints,
        PBYTE   pOTypes,
        size_t  pOMaxLength
    )
{
    IRect       = (GRECT*) InnerRect ;
    ORect       = (GRECT*) OuterRect ;
    OPoints     = pOPoints ;
    OTypes      = pOTypes ;
    OMaxLength  = pOMaxLength ;
    OLength     = 0 ;

    if ( ILength <= 0 )
        return 0 ;

    try {

        Index = 0 ;
        while ( Index<ILength )
        {
            OFirstPoint = TRUE ;
            POINT StartPoint = IPoints[Index++] ;
            LastSector = GetSector( StartPoint ) ;
            LastPoint = StartPoint ;
            while ( Index<ILength && (IsLine(ITypes[Index]) || IsCurve(ITypes[Index])) )
            {
                if ( IsLine(ITypes[Index]) )
                {
                    ClipLine( LastPoint,IPoints[Index] ) ;
                    LastPoint = IPoints[Index++] ;
                }
                else
                {
                    ClipCurve( LastPoint,IPoints[Index],IPoints[Index+1],IPoints[Index+2] ) ;
                    LastPoint = IPoints[Index+2] ;
                    Index += 3 ;
                }
            }
            if ( IsClosed || (ITypes[Index-1] & PT_CLOSEFIGURE) )
            {
                ClipLine( LastPoint,StartPoint ) ;
                if ( !OFirstPoint )
                    *(OTypes-1) |= PT_CLOSEFIGURE ;
            }
            if ( !OFirstPoint && IsMove(*(OTypes-1)) )
            {
                OTypes-- ;
                OPoints-- ;
                OLength-- ;
            }
        }

    } catch ( INT32 ) {
        OLength = (size_t)-1 ;
    }

    return OLength ;
}

---