// PolyLine.cpp ... implementation of CPolyLine class from FreePCB.

//
// implementation for kicad and kbool polygon clipping library
//
using namespace std;

#include <math.h>
#include <vector>

#include "fctsys.h"


#include "PolyLine.h"


#define pi 3.14159265359

CPolyLine::CPolyLine()
{
    m_HatchStyle = 0;
    m_Width = 0;
    utility = 0;
    m_Kbool_Poly_Engine = NULL;
}


// destructor, removes display elements
//
CPolyLine::~CPolyLine()
{
    Undraw();
    if ( m_Kbool_Poly_Engine )
        delete m_Kbool_Poly_Engine;
}

/** Function NormalizeWithKbool
 * Use the Kbool Library to clip contours: if outlines are crossing, the self-crossing polygon
 * is converted to non self-crossing polygon by adding extra points at the crossing locations
 * and reordering corners
 * if more than one outside contour are found, extra CPolyLines will be created
 * because copper areas have only one outside contour
 * Therefore, if this results in new CPolyLines, return them as std::vector pa
 * @param aExtraPolys: pointer on a std::vector<CPolyLine*> to store extra CPolyLines
 * @param bRetainArcs == TRUE, try to retain arcs in polys
 * @return number of external contours, or -1 if error
 */
int CPolyLine::NormalizeWithKbool( std::vector<CPolyLine*> * aExtraPolyList, bool bRetainArcs )
{
    std::vector<CArc>   arc_array;
    std::vector <void*> hole_array; // list of holes
    std::vector<int> *  hole;       // used to store corners for a given hole
    CPolyLine*          polyline;
    int n_ext_cont = 0;             // CPolyLine count

    /* Creates a bool engine from this CPolyLine.
     * Normalized outlines and holes will be in m_Kbool_Poly_Engine
     * If some polygons are self crossing, after running the Kbool Engine, self crossing polygons
     * will be converted in non self crossing polygons by inserting extra points at the crossing locations
     * True holes are combined if possible
     */
    if( bRetainArcs )
        MakeKboolPoly( -1, -1, &arc_array );
    else
        MakeKboolPoly( -1, -1, NULL );

    Undraw();

    /* now, recreate polys
     * if more than one outside contour are found, extra CPolyLines will be created
     * because copper areas have only one outside contour
     * the first outside contour found is the new "this" outside contour
     * if others outside contours are found we create new CPolyLines
     * Note: if there are holes in polygons, we must store them
     * and when all outside contours are found, search the corresponding outside contour for each hole
     */
    while( m_Kbool_Poly_Engine->StartPolygonGet() )
    {
        // See if the current polygon is flagged as a hole
        if( m_Kbool_Poly_Engine->GetPolygonPointEdgeType() == KB_INSIDE_EDGE )
        {
            hole = new std::vector<int>;
            hole_array.push_back( hole );
            while( m_Kbool_Poly_Engine->PolygonHasMorePoints() )    // store hole
            {
                int x = (int)m_Kbool_Poly_Engine->GetPolygonXPoint();
                int y = (int)m_Kbool_Poly_Engine->GetPolygonYPoint();
                hole->push_back( x );
                hole->push_back( y );
            }

            m_Kbool_Poly_Engine->EndPolygonGet();
        }
        else if( n_ext_cont == 0 )
        {
            // first external contour, replace this poly
            corner.clear();
            side_style.clear();
            bool first = true;
            while( m_Kbool_Poly_Engine->PolygonHasMorePoints() )
            {       // foreach point in the polygon
                int x = (int)m_Kbool_Poly_Engine->GetPolygonXPoint();
                int y = (int)m_Kbool_Poly_Engine->GetPolygonYPoint();
                if( first )
                {
                    first = false;
                    Start( GetLayer(), x, y, GetHatchStyle() );
                }
                else
                    AppendCorner( x, y );
            }

            m_Kbool_Poly_Engine->EndPolygonGet();
            Close();
            n_ext_cont++;
        }
        else if( aExtraPolyList )                                               // a new outside contour is found: create a new CPolyLine
        {
            polyline = new CPolyLine;                               // create new poly
            aExtraPolyList->push_back( polyline );                              // put it in array
            bool first = true;
            while( m_Kbool_Poly_Engine->PolygonHasMorePoints() )    // read next external contour
            {
                int x = (int)m_Kbool_Poly_Engine->GetPolygonXPoint();
                int y = (int)m_Kbool_Poly_Engine->GetPolygonYPoint();
                if( first )
                {
                    first = false;
                    polyline->Start( GetLayer(), x, y, GetHatchStyle() );
                }
                else
                    polyline->AppendCorner( x, y );
            }

            m_Kbool_Poly_Engine->EndPolygonGet();
            polyline->Close( STRAIGHT, FALSE );
            n_ext_cont++;
        }
    }

    // now add cutouts to the corresponding CPolyLine(s)
    for( unsigned ii = 0; ii < hole_array.size(); ii++ )
    {
        hole     = (std::vector<int> *)hole_array[ii];
        polyline = NULL;
        if( n_ext_cont == 1 )
        {
            polyline = this;
        }
        else
        {
            // find the polygon that contains this hole
            // testing one corner inside is enought because a hole is entirely inside the polygon
            // sowe test only the first corner
            int x = (*hole)[0];
            int y = (*hole)[1];
            if( TestPointInside( x, y ) )
                polyline = this;
            else if( aExtraPolyList )
            {
                for( int ext_ic = 0; ext_ic<n_ext_cont - 1; ext_ic++ )
                {
                    if( (*aExtraPolyList)[ext_ic]->TestPointInside( x, y ) )
                    {
                        polyline = (*aExtraPolyList)[ext_ic];
                        break;
                    }
                }
            }
        }

        if( !polyline )
            wxASSERT( 0 );
        else
        {
            for( unsigned ii = 0; ii< (*hole).size(); ii++ )
            {
                int x = (*hole)[ii]; ii++;
                int y = (*hole)[ii];
                polyline->AppendCorner( x, y, STRAIGHT, FALSE );
            }

            polyline->Close( STRAIGHT, FALSE );
        }
    }

    if( bRetainArcs )
        RestoreArcs( &arc_array, aExtraPolyList );

    delete m_Kbool_Poly_Engine;
    m_Kbool_Poly_Engine = NULL;

    // free hole list
    for( unsigned ii = 0; ii < hole_array.size(); ii++ )
        delete (std::vector<int> *)hole_array[ii];

    return n_ext_cont;
}


/** Function AddPolygonsToBoolEng
 * and edges contours to a kbool engine, preparing a boolean op between polygons
 * @param aStart_contour: starting contour number (-1 = all, 0 is the outlines of zone, > 1 = holes in zone
 * @param aEnd_contour: ending contour number (-1 = all after  aStart_contour)
 * @param arc_array: arc converted to poly segments (NULL if not exists)
 * @param aBooleng : pointer on a bool engine (handle a set of polygons)
 * @param aGroup : group to fill (aGroup = GROUP_A or GROUP_B) operations are made between GROUP_A and GROUP_B
 */
int CPolyLine::AddPolygonsToBoolEng( Bool_Engine*        aBooleng,
                                     GroupType           aGroup,
                                     int                 aStart_contour,
                                     int                 aEnd_contour,
                                     std::vector<CArc> * arc_array )
{
    int count = 0;

    if( (aGroup != GROUP_A) && (aGroup != GROUP_B ) )
        return 0; //Error !

    MakeKboolPoly( aStart_contour, aEnd_contour, arc_array );

    while( m_Kbool_Poly_Engine->StartPolygonGet() )
    {
        if( aBooleng->StartPolygonAdd( GROUP_A ) )
        {
            while( m_Kbool_Poly_Engine->PolygonHasMorePoints() )
            {
                int x = (int)m_Kbool_Poly_Engine->GetPolygonXPoint();
                int y = (int)m_Kbool_Poly_Engine->GetPolygonYPoint();
                aBooleng->AddPoint( x, y );
                count++;
            }

            aBooleng->EndPolygonAdd();
        }
        m_Kbool_Poly_Engine->EndPolygonGet();
    }

    delete m_Kbool_Poly_Engine;
    m_Kbool_Poly_Engine = NULL;

    return count;
}


/** Function MakeKboolPoly
 * fill a kbool engine with a closed polyline contour
 * approximates arcs with multiple straight-line segments
 * @param aStart_contour: starting contour number (-1 = all, 0 is the outlines of zone, > 1 = holes in zone
 * @param aEnd_contour: ending contour number (-1 = all after  aStart_contour)
 *  combining intersecting contours if possible
 * @param arc_array : return corners computed from arcs approximations in arc_array
 * @return error: 0 if Ok, 1 if error
 */
int CPolyLine::MakeKboolPoly( int aStart_contour, int aEnd_contour, std::vector<CArc> * arc_array )
{
    if( m_Kbool_Poly_Engine )
    {
        delete m_Kbool_Poly_Engine;
        m_Kbool_Poly_Engine = NULL;
    }
    if( !GetClosed() && (aStart_contour == (GetNumContours() - 1) || aStart_contour == -1) )
        return 1; // error

    int n_arcs = 0;

    int first_contour = aStart_contour;
    int last_contour  = aEnd_contour;
    if( aStart_contour == -1 )
    {
        first_contour = 0;
        last_contour  = GetNumContours() - 1;
    }
    if( aEnd_contour == -1 )
    {
        last_contour = GetNumContours() - 1;
    }
    if( arc_array )
        arc_array->clear();
    int iarc = 0;
    for( int icont = first_contour; icont<=last_contour; icont++ )
    {
        // Fill a kbool engine for this contour,
        // and combine it with previous contours
        Bool_Engine* booleng = new Bool_Engine();
        ArmBoolEng( booleng );

        if( m_Kbool_Poly_Engine )  // a previous contour exists. Put it in new engine
        {
            while( m_Kbool_Poly_Engine->StartPolygonGet() )
            {
                if( booleng->StartPolygonAdd( GROUP_A ) )
                {
                    while( m_Kbool_Poly_Engine->PolygonHasMorePoints() )
                    {
                        int x = (int)m_Kbool_Poly_Engine->GetPolygonXPoint();
                        int y = (int)m_Kbool_Poly_Engine->GetPolygonYPoint();
                        booleng->AddPoint( x, y );
                    }

                    booleng->EndPolygonAdd();
                }
                m_Kbool_Poly_Engine->EndPolygonGet();
            }
        }

        // first, calculate number of vertices in contour
        int n_vertices = 0;
        int ic_st  = GetContourStart( icont );
        int ic_end = GetContourEnd( icont );
        if( !booleng->StartPolygonAdd( GROUP_B ) )
        {
            wxASSERT( 0 );
            return 1;   //error
        }
        for( int ic = ic_st; ic<=ic_end; ic++ )
        {
            int style = side_style[ic];
            int x1    = corner[ic].x;
            int y1    = corner[ic].y;
            int x2, y2;
            if( ic < ic_end )
            {
                x2 = corner[ic + 1].x;
                y2 = corner[ic + 1].y;
            }
            else
            {
                x2 = corner[ic_st].x;
                y2 = corner[ic_st].y;
            }
            if( style == STRAIGHT )
                n_vertices++;
            else
            {
                // style is ARC_CW or ARC_CCW
                int n;                          // number of steps for arcs
                n = ( abs( x2 - x1 ) + abs( y2 - y1 ) ) / (CArc::MAX_STEP);
                n = max( n, CArc::MIN_STEPS );  // or at most 5 degrees of arc
                n_vertices += n;
                n_arcs++;
            }
        }

        // now enter this contour to booleng
        int ivtx = 0;
        for( int ic = ic_st; ic<=ic_end; ic++ )
        {
            int style = side_style[ic];
            int x1    = corner[ic].x;
            int y1    = corner[ic].y;
            int x2, y2;
            if( ic < ic_end )
            {
                x2 = corner[ic + 1].x;
                y2 = corner[ic + 1].y;
            }
            else
            {
                x2 = corner[ic_st].x;
                y2 = corner[ic_st].y;
            }
            if( style == STRAIGHT )
            {
                booleng->AddPoint( x1, y1 );
                ivtx++;
            }
            else
            {
                // style is arc_cw or arc_ccw
                int    n;                       // number of steps for arcs
                n = ( abs( x2 - x1 ) + abs( y2 - y1 ) ) / (CArc::MAX_STEP);
                n = max( n, CArc::MIN_STEPS );  // or at most 5 degrees of arc
                double xo, yo, theta1, theta2, a, b;
                a = fabs( (double) (x1 - x2) );
                b = fabs( (double) (y1 - y2) );
                if( style == CPolyLine::ARC_CW )
                {
                    // clockwise arc (ie.quadrant of ellipse)
                    if( x2 > x1 && y2 > y1 )
                    {
                        // first quadrant, draw second quadrant of ellipse
                        xo     = x2;
                        yo     = y1;
                        theta1 = pi;
                        theta2 = pi / 2.0;
                    }
                    else if( x2 < x1 && y2 > y1 )
                    {
                        // second quadrant, draw third quadrant of ellipse
                        xo     = x1;
                        yo     = y2;
                        theta1 = 3.0 * pi / 2.0;
                        theta2 = pi;
                    }
                    else if( x2 < x1 && y2 < y1 )
                    {
                        // third quadrant, draw fourth quadrant of ellipse
                        xo     = x2;
                        yo     = y1;
                        theta1 = 2.0 * pi;
                        theta2 = 3.0 * pi / 2.0;
                    }
                    else
                    {
                        xo     = x1; // fourth quadrant, draw first quadrant of ellipse
                        yo     = y2;
                        theta1 = pi / 2.0;
                        theta2 = 0.0;
                    }
                }
                else
                {
                    // counter-clockwise arc
                    if( x2 > x1 && y2 > y1 )
                    {
                        xo     = x1; // first quadrant, draw fourth quadrant of ellipse
                        yo     = y2;
                        theta1 = 3.0 * pi / 2.0;
                        theta2 = 2.0 * pi;
                    }
                    else if( x2 < x1 && y2 > y1 )
                    {
                        xo     = x2; // second quadrant
                        yo     = y1;
                        theta1 = 0.0;
                        theta2 = pi / 2.0;
                    }
                    else if( x2 < x1 && y2 < y1 )
                    {
                        xo     = x1; // third quadrant
                        yo     = y2;
                        theta1 = pi / 2.0;
                        theta2 = pi;
                    }
                    else
                    {
                        xo     = x2; // fourth quadrant
                        yo     = y1;
                        theta1 = pi;
                        theta2 = 3.0 * pi / 2.0;
                    }
                }

                // now write steps for arc
                if( arc_array )
                {
                    CArc new_arc;
                    new_arc.style   = style;
                    new_arc.n_steps = n;
                    new_arc.xi = x1;
                    new_arc.yi = y1;
                    new_arc.xf = x2;
                    new_arc.yf = y2;
                    arc_array->push_back( new_arc );
                    iarc++;
                }
                for( int is = 0; is<n; is++ )
                {
                    double theta = theta1 + ( (theta2 - theta1) * (double) is ) / n;
                    double x = xo + a* cos( theta );
                    double y = yo + b* sin( theta );
                    if( is == 0 )
                    {
                        x = x1;
                        y = y1;
                    }
                    booleng->AddPoint( x1, y1 );
                    ivtx++;
                }
            }
        }

        if( n_vertices != ivtx )
            wxASSERT( 0 );

        //  close list added to the bool engine
        booleng->EndPolygonAdd();

        /* now combine polygon to the previous polygons.
         * note: the first polygon is the outline contour, and others are holes inside the first polygon
         * The first polygon is ORed with nothing, but is is a trick to sort corners (vertex)
         * clockwise with the kbool engine.
         * Others polygons are substract to the outline and corners will be ordered counter clockwise
         * by the kbool engine
         */
        if( aStart_contour <= 0 && icont != 0 )  // substract hole to outside ( if the outline contour is take in account)
        {
            booleng->Do_Operation( BOOL_A_SUB_B );
        }
        else       // add outside or add holes if we do not use the outline contour
        {
            booleng->Do_Operation( BOOL_OR );
        }

        // now copy result to m_gpc_poly
        if( m_Kbool_Poly_Engine )
            delete m_Kbool_Poly_Engine;
        m_Kbool_Poly_Engine = booleng;
    }

    return 0;
}


/** Function ArmBoolEng
 * Initialise parameters used in kbool
 * @param aBooleng = pointer to the Bool_Engine to initialise
 * @param aConvertHoles = mode for holes when a boolean operation is made
 *   true: holes are linked into outer contours by double overlapping segments
 *   false: holes are not linked: in this mode contours are added clockwise
 *          and polygons added counter clockwise are holes
 */
void ArmBoolEng( Bool_Engine* aBooleng, bool aConvertHoles )
{
    // set some global vals to arm the boolean engine
    double DGRID = 1000;    // round coordinate X or Y value in calculations to this
    double MARGE = 0.001;   // snap with in this range points to lines in the intersection routines
                            // should always be > DGRID  a  MARGE >= 10*DGRID is oke
                            // this is also used to remove small segments and to decide when
                            // two segments are in line.
    double CORRECTIONFACTOR = 500.0;    // correct the polygons by this number
    double CORRECTIONABER   = 1.0;      // the accuracy for the rounded shapes used in correction
    double ROUNDFACTOR  = 1.5;          // when will we round the correction shape to a circle
    double SMOOTHABER   = 10.0;         // accuracy when smoothing a polygon
    double MAXLINEMERGE = 1000.0;       // leave as is, segments of this length in smoothen


    // DGRID is only meant to make fractional parts of input data which
    // are doubles, part of the integers used in vertexes within the boolean algorithm.
    // Within the algorithm all input data is multiplied with DGRID

    // space for extra intersection inside the boolean algorithms
    // only change this if there are problems
    int GRID = 10000;

    aBooleng->SetMarge( MARGE );
    aBooleng->SetGrid( GRID );
    aBooleng->SetDGrid( DGRID );
    aBooleng->SetCorrectionFactor( CORRECTIONFACTOR );
    aBooleng->SetCorrectionAber( CORRECTIONABER );
    aBooleng->SetSmoothAber( SMOOTHABER );
    aBooleng->SetMaxlinemerge( MAXLINEMERGE );
    aBooleng->SetRoundfactor( ROUNDFACTOR );

    if( aConvertHoles )
    {
        aBooleng->SetLinkHoles( true );                 // holes will be connected by double overlapping segments
        aBooleng->SetOrientationEntryMode( false );     // all polygons are contours, not holes
    }
    else
    {
        aBooleng->SetLinkHoles( false );                // holes will not ce connected by double overlapping segments
        aBooleng->SetOrientationEntryMode( true );      // holes are entered counter clockwise
    }
}



int CPolyLine::NormalizeAreaOutlines( std::vector<CPolyLine*> * pa, bool bRetainArcs )
{
    return NormalizeWithKbool( pa, bRetainArcs );
}

// Restore arcs to a polygon where they were replaced with steps
// If pa != NULL, also use polygons in pa array
//
int CPolyLine::RestoreArcs( std::vector<CArc> * arc_array, std::vector<CPolyLine*> * pa )
{
    // get poly info
    int n_polys = 1;

    if( pa )
        n_polys += pa->size();
    CPolyLine* poly;

    // undraw polys and clear utility flag for all corners
    for( int ip = 0; ip<n_polys; ip++ )
    {
        if( ip == 0 )
            poly = this;
        else
            poly = (*pa)[ip - 1];
        poly->Undraw();
        for( int ic = 0; ic<poly->GetNumCorners(); ic++ )
            poly->SetUtility( ic, 0 );

        // clear utility flag
    }

    // find arcs and replace them
    bool bFound;
    int  arc_start = 0;
    int  arc_end   = 0;
    for( unsigned iarc = 0; iarc<arc_array->size(); iarc++ )
    {
        int arc_xi  = (*arc_array)[iarc].xi;
        int arc_yi  = (*arc_array)[iarc].yi;
        int arc_xf  = (*arc_array)[iarc].xf;
        int arc_yf  = (*arc_array)[iarc].yf;
        int n_steps = (*arc_array)[iarc].n_steps;
        int style   = (*arc_array)[iarc].style;
        bFound = FALSE;

        // loop through polys
        for( int ip = 0; ip<n_polys; ip++ )
        {
            if( ip == 0 )
                poly = this;
            else
                poly = (*pa)[ip - 1];
            for( int icont = 0; icont<poly->GetNumContours(); icont++ )
            {
                int ic_start = poly->GetContourStart( icont );
                int ic_end   = poly->GetContourEnd( icont );
                if( (ic_end - ic_start) > n_steps )
                {
                    for( int ic = ic_start; ic<=ic_end; ic++ )
                    {
                        int ic_next = ic + 1;
                        if( ic_next > ic_end )
                            ic_next = ic_start;
                        int xi = poly->GetX( ic );
                        int yi = poly->GetY( ic );
                        if( xi == arc_xi && yi == arc_yi )
                        {
                            // test for forward arc
                            int ic2 = ic + n_steps;
                            if( ic2 > ic_end )
                                ic2 = ic2 - ic_end + ic_start - 1;
                            int xf = poly->GetX( ic2 );
                            int yf = poly->GetY( ic2 );
                            if( xf == arc_xf && yf == arc_yf )
                            {
                                // arc from ic to ic2
                                bFound    = TRUE;
                                arc_start = ic;
                                arc_end   = ic2;
                            }
                            else
                            {
                                // try reverse arc
                                ic2 = ic - n_steps;
                                if( ic2 < ic_start )
                                    ic2 = ic2 - ic_start + ic_end + 1;
                                xf = poly->GetX( ic2 );
                                yf = poly->GetY( ic2 );
                                if( xf == arc_xf && yf == arc_yf )
                                {
                                    // arc from ic2 to ic
                                    bFound    = TRUE;
                                    arc_start = ic2;
                                    arc_end   = ic;
                                    style = 3 - style;
                                }
                            }
                            if( bFound )
                            {
                                poly->side_style[arc_start] = style;

                                // mark corners for deletion from arc_start+1 to arc_end-1
                                for( int i = arc_start + 1; i!=arc_end; )
                                {
                                    if( i > ic_end )
                                        i = ic_start;
                                    poly->SetUtility( i, 1 );
                                    if( i == ic_end )
                                        i = ic_start;
                                    else
                                        i++;
                                }

                                break;
                            }
                        }
                        if( bFound )
                            break;
                    }
                }
                if( bFound )
                    break;
            }
        }

        if( bFound )
            (*arc_array)[iarc].bFound = TRUE;
    }

    // now delete all marked corners
    for( int ip = 0; ip<n_polys; ip++ )
    {
        if( ip == 0 )
            poly = this;
        else
            poly = (*pa)[ip - 1];
        for( int ic = poly->GetNumCorners() - 1; ic>=0; ic-- )
        {
            if( poly->GetUtility( ic ) )
                poly->DeleteCorner( ic, FALSE );
        }
    }

    return 0;
}


// initialize new polyline
// set layer, width, selection box size, starting point, id and pointer
//
// if sel_box = 0, don't create selection elements at all
//
// if polyline is board outline, enter with:
//	id.type = ID_BOARD
//	id.st = ID_BOARD_OUTLINE
//	id.i = 0
//	ptr = NULL
//
// if polyline is copper area, enter with:
//	id.type = ID_NET;
//	id.st = ID_AREA
//	id.i = index to area
//	ptr = pointer to net
//
void CPolyLine::Start( int layer, int x, int y, int hatch )
{
    m_layer      = layer;
    m_HatchStyle = hatch;
    CPolyPt poly_pt( x, y );
    poly_pt.end_contour = FALSE;

    corner.push_back( poly_pt );
    side_style.push_back( 0 );
}


// add a corner to unclosed polyline
//
void CPolyLine::AppendCorner( int x, int y, int style, bool bDraw )
{
    Undraw();
    CPolyPt poly_pt( x, y );
    poly_pt.end_contour = FALSE;

    // add entries for new corner and side
    corner.push_back( poly_pt );
    side_style.push_back( style );
    if( corner.size() > 0 && !corner[corner.size() - 1].end_contour )
        side_style[corner.size() - 1] = style;
    int dl_type;
    if( style == CPolyLine::STRAIGHT )
        dl_type = DL_LINE;
    else if( style == CPolyLine::ARC_CW )
        dl_type = DL_ARC_CW;
    else if( style == CPolyLine::ARC_CCW )
        dl_type = DL_ARC_CCW;
    else
        wxASSERT( 0 );
    if( bDraw )
        Draw();
}


// close last polyline contour
//
void CPolyLine::Close( int style, bool bDraw )
{
    if( GetClosed() )
        wxASSERT( 0 );
    Undraw();
    side_style[corner.size() - 1] = style;
    corner[corner.size() - 1].end_contour = TRUE;
    if( bDraw )
        Draw();
}


// move corner of polyline
//
void CPolyLine::MoveCorner( int ic, int x, int y )
{
    Undraw();
    corner[ic].x = x;
    corner[ic].y = y;
    Draw();
}


// delete corner and adjust arrays
//
void CPolyLine::DeleteCorner( int ic, bool bDraw )
{
    Undraw();
    int  icont   = GetContour( ic );
    int  istart  = GetContourStart( icont );
    int  iend    = GetContourEnd( icont );
    bool bClosed = icont < GetNumContours() - 1 || GetClosed();

    if( !bClosed )
    {
        // open contour, must be last contour
        corner.erase( corner.begin() + ic );

        if( ic != istart )
            side_style.erase( side_style.begin() + ic - 1 );
    }
    else
    {
        // closed contour
        corner.erase( corner.begin() + ic );
        side_style.erase( side_style.begin() + ic );
        if( ic == iend )
            corner[ic - 1].end_contour = TRUE;
    }
    if( bClosed && GetContourSize( icont ) < 3 )
    {
        // delete the entire contour
        RemoveContour( icont );
    }
    if( bDraw )
        Draw();
}


/******************************************/
void CPolyLine::RemoveContour( int icont )
/******************************************/

/**
 * Function RemoveContour
 * @param icont = contour number to remove
 * remove a contour only if there is more than 1 contour
 */
{
    Undraw();
    int istart = GetContourStart( icont );
    int iend   = GetContourEnd( icont );

    if( icont == 0 && GetNumContours() == 1 )
    {
        // remove the only contour
        wxASSERT( 0 );
    }
    else if( icont == GetNumContours() - 1 )
    {
        // remove last contour
        corner.erase( corner.begin() + istart, corner.end() );
        side_style.erase( side_style.begin() + istart, side_style.end() );
    }
    else
    {
        // remove closed contour
        for( int ic = iend; ic>=istart; ic-- )
        {
            corner.erase( corner.begin() + ic );
            side_style.erase( side_style.begin() + ic );
        }
    }
    Draw();
}


/******************************************/
void CPolyLine::RemoveAllContours( void )
/******************************************/

/**
 * function RemoveAllContours
 * removes all corners from the lists.
 * Others params are not chnaged
 */
{
    corner.clear();
    side_style.clear();
}


/** Function InsertCorner
 * insert a new corner between two existing corners
 * @param ic = index for the insertion point: the corner is inserted AFTER ic
 * @param x, y = coordinates corner to insert
 */
void CPolyLine::InsertCorner( int ic, int x, int y )
{
    Undraw();
    if( (unsigned) (ic) >= corner.size() )
    {
        corner.push_back( CPolyPt( x, y ) );
        side_style.push_back( STRAIGHT );
    }
    else
    {
        corner.insert( corner.begin() + ic + 1, CPolyPt( x, y ) );
        side_style.insert( side_style.begin() + ic + 1, STRAIGHT );
    }

    if( (unsigned) (ic + 1) < corner.size() )
    {
        if( corner[ic].end_contour )
        {
            corner[ic + 1].end_contour = TRUE;
            corner[ic].end_contour = FALSE;
        }
    }
    Draw();
}


// undraw polyline by removing all graphic elements from display list
//
void CPolyLine::Undraw()
{
    m_HatchLines.clear();
    bDrawn = FALSE;
}


// draw polyline by adding all graphics to display list
// if side style is ARC_CW or ARC_CCW but endpoints are not angled,
// convert to STRAIGHT
//
void CPolyLine::Draw()
{
    // first, undraw if necessary
    if( bDrawn )
        Undraw();

    Hatch();
    bDrawn = TRUE;
}


int CPolyLine::GetX( int ic )
{
    return corner[ic].x;
}


int CPolyLine::GetY( int ic )
{
    return corner[ic].y;
}


int CPolyLine::GetEndContour( int ic )
{
    return corner[ic].end_contour;
}


CRect CPolyLine::GetBounds()
{
    CRect r = GetCornerBounds();

    r.left   -= m_Width / 2;
    r.right  += m_Width / 2;
    r.bottom -= m_Width / 2;
    r.top += m_Width / 2;
    return r;
}


CRect CPolyLine::GetCornerBounds()
{
    CRect r;

    r.left  = r.bottom = INT_MAX;
    r.right = r.top = INT_MIN;
    for( unsigned i = 0; i<corner.size(); i++ )
    {
        r.left   = min( r.left, corner[i].x );
        r.right  = max( r.right, corner[i].x );
        r.bottom = min( r.bottom, corner[i].y );
        r.top    = max( r.top, corner[i].y );
    }

    return r;
}


CRect CPolyLine::GetCornerBounds( int icont )
{
    CRect r;

    r.left  = r.bottom = INT_MAX;
    r.right = r.top = INT_MIN;
    int istart = GetContourStart( icont );
    int iend   = GetContourEnd( icont );
    for( int i = istart; i<=iend; i++ )
    {
        r.left   = min( r.left, corner[i].x );
        r.right  = max( r.right, corner[i].x );
        r.bottom = min( r.bottom, corner[i].y );
        r.top    = max( r.top, corner[i].y );
    }

    return r;
}


int CPolyLine::GetNumCorners()
{
    return corner.size();
}


int CPolyLine::GetNumSides()
{
    if( GetClosed() )
        return corner.size();
    else
        return corner.size() - 1;
}


int CPolyLine::GetNumContours()
{
    int ncont = 0;

    if( !corner.size() )
        return 0;

    for( unsigned ic = 0; ic<corner.size(); ic++ )
        if( corner[ic].end_contour )
            ncont++;

    if( !corner[corner.size() - 1].end_contour )
        ncont++;
    return ncont;
}


int CPolyLine::GetContour( int ic )
{
    int ncont = 0;

    for( int i = 0; i<ic; i++ )
    {
        if( corner[i].end_contour )
            ncont++;
    }

    return ncont;
}


int CPolyLine::GetContourStart( int icont )
{
    if( icont == 0 )
        return 0;

    int ncont = 0;
    for( unsigned i = 0; i<corner.size(); i++ )
    {
        if( corner[i].end_contour )
        {
            ncont++;
            if( ncont == icont )
                return i + 1;
        }
    }

    wxASSERT( 0 );
    return 0;
}


int CPolyLine::GetContourEnd( int icont )
{
    if( icont < 0 )
        return 0;

    if( icont == GetNumContours() - 1 )
        return corner.size() - 1;

    int ncont = 0;
    for( unsigned i = 0; i<corner.size(); i++ )
    {
        if( corner[i].end_contour )
        {
            if( ncont == icont )
                return i;
            ncont++;
        }
    }

    wxASSERT( 0 );
    return 0;
}


int CPolyLine::GetContourSize( int icont )
{
    return GetContourEnd( icont ) - GetContourStart( icont ) + 1;
}


void CPolyLine::SetSideStyle( int is, int style )
{
    Undraw();
    CPoint p1, p2;
    if( is == (int) (corner.size() - 1) )
    {
        p1.x = corner[corner.size() - 1].x;
        p1.y = corner[corner.size() - 1].y;
        p2.x = corner[0].x;
        p2.y = corner[0].y;
    }
    else
    {
        p1.x = corner[is].x;
        p1.y = corner[is].y;
        p2.x = corner[is + 1].x;
        p2.y = corner[is + 1].y;
    }
    if( p1.x == p2.x || p1.y == p2.y )
        side_style[is] = STRAIGHT;
    else
        side_style[is] = style;
    Draw();
}


int CPolyLine::GetSideStyle( int is )
{
    return side_style[is];
}


int CPolyLine::GetClosed()
{
    if( corner.size() == 0 )
        return 0;
    else
        return corner[corner.size() - 1].end_contour;
}


// draw hatch lines
//
void CPolyLine::Hatch()
{
    m_HatchLines.clear();
    if( m_HatchStyle == NO_HATCH )
    {
        return;
    }

    int layer = GetLayer();

    if( GetClosed() )   // If not closed, the poly is beeing created and not finalised. Not not hatch
    {
        enum {
            MAXPTS = 100,
        };
        int    xx[MAXPTS], yy[MAXPTS];

        // define range for hatch lines
        int    min_x = corner[0].x;
        int    max_x = corner[0].x;
        int    min_y = corner[0].y;
        int    max_y = corner[0].y;
        for( unsigned ic = 1; ic < corner.size(); ic++ )
        {
            if( corner[ic].x < min_x )
                min_x = corner[ic].x;
            if( corner[ic].x > max_x )
                max_x = corner[ic].x;
            if( corner[ic].y < min_y )
                min_y = corner[ic].y;
            if( corner[ic].y > max_y )
                max_y = corner[ic].y;
        }

        int    slope_flag = (layer & 1) ? 1 : -1; // 1 or -1
        double slope = 0.707106 * slope_flag;
        int    spacing;
        if( m_HatchStyle == DIAGONAL_EDGE )
            spacing = 10 * PCBU_PER_MIL;
        else
            spacing = 50 * PCBU_PER_MIL;
        int max_a, min_a;
        if( slope_flag == 1 )
        {
            max_a = (int) (max_y - slope * min_x);
            min_a = (int) (min_y - slope * max_x);
        }
        else
        {
            max_a = (int) (max_y - slope * max_x);
            min_a = (int) (min_y - slope * min_x);
        }
        min_a = (min_a / spacing) * spacing;

        // calculate an offset depending on layer number, for a better display of hatches on a multilayer board
        int offset = (layer * 7) / 8;
        min_a += offset;

        // now calculate and draw hatch lines
        int nc = corner.size();

        // loop through hatch lines
        for( int a = min_a; a<max_a; a += spacing )
        {
            // get intersection points for this hatch line
            int nloops = 0;
            int npts;

            // make this a loop in case my homebrew hatching algorithm screws up
            do
            {
                npts = 0;
                int i_start_contour = 0;
                for( int ic = 0; ic<nc; ic++ )
                {
                    double x, y, x2, y2;
                    int    ok;
                    if( corner[ic].end_contour || ( ic == (int) (corner.size() - 1) ) )
                    {
                        ok = FindLineSegmentIntersection( a, slope,
                                                          corner[ic].x, corner[ic].y,
                                                          corner[i_start_contour].x,
                                                          corner[i_start_contour].y,
                                                          side_style[ic],
                                                          &x, &y, &x2, &y2 );
                        i_start_contour = ic + 1;
                    }
                    else
                    {
                        ok = FindLineSegmentIntersection( a, slope,
                                                          corner[ic].x, corner[ic].y,
                                                          corner[ic + 1].x, corner[ic + 1].y,
                                                          side_style[ic],
                                                          &x, &y, &x2, &y2 );
                    }
                    if( ok )
                    {
                        xx[npts] = (int) x;
                        yy[npts] = (int) y;
                        npts++;
                        wxASSERT( npts<MAXPTS );    // overflow
                    }
                    if( ok == 2 )
                    {
                        xx[npts] = (int) x2;
                        yy[npts] = (int) y2;
                        npts++;
                        wxASSERT( npts<MAXPTS );    // overflow
                    }
                }

                nloops++;
                a += PCBU_PER_MIL / 100;
            } while( npts % 2 != 0 && nloops < 3 );

/*  DICK 1/22/08: this was firing repeatedly on me, needed to comment out to get
 * my work done:
 *         wxASSERT( npts%2==0 );	// odd number of intersection points, error
 */

            // sort points in order of descending x (if more than 2)
            if( npts>2 )
            {
                for( int istart = 0; istart<(npts - 1); istart++ )
                {
                    int max_x = INT_MIN;
                    int imax  = INT_MIN;
                    for( int i = istart; i<npts; i++ )
                    {
                        if( xx[i] > max_x )
                        {
                            max_x = xx[i];
                            imax  = i;
                        }
                    }

                    int temp = xx[istart];
                    xx[istart] = xx[imax];
                    xx[imax]   = temp;
                    temp = yy[istart];
                    yy[istart] = yy[imax];
                    yy[imax]   = temp;
                }
            }

            // draw lines
            for( int ip = 0; ip<npts; ip += 2 )
            {
                double dx = xx[ip + 1] - xx[ip];
                if( m_HatchStyle == DIAGONAL_FULL || fabs( dx ) < 40 * NM_PER_MIL )
                {
                    m_HatchLines.push_back( CSegment( xx[ip], yy[ip], xx[ip + 1], yy[ip + 1] ) );
                }
                else
                {
                    double dy    = yy[ip + 1] - yy[ip];
                    double slope = dy / dx;
                    if( dx > 0 )
                        dx = 20 * NM_PER_MIL;
                    else
                        dx = -20 * NM_PER_MIL;
                    double x1 = xx[ip] + dx;
                    double x2 = xx[ip + 1] - dx;
                    double y1 = yy[ip] + dx * slope;
                    double y2 = yy[ip + 1] - dx * slope;
                    m_HatchLines.push_back( CSegment( xx[ip], yy[ip], to_int( x1 ), to_int( y1 ) ) );
                    m_HatchLines.push_back( CSegment( xx[ip + 1], yy[ip + 1], to_int( x2 ),
                                                     to_int( y2 ) ) );
                }
            }
        }

        // end for
    }
}


// test to see if a point is inside polyline
//
bool CPolyLine::TestPointInside( int x, int y )
{
    enum {
        MAXPTS = 100
    };
    if( !GetClosed() )
        wxASSERT( 0 );

    // define line passing through (x,y), with slope = 2/3;
    // get intersection points
    double xx[MAXPTS], yy[MAXPTS];
    double slope = (double) 2.0 / 3.0;
    double a      = y - slope * x;
    int    nloops = 0;
    int    npts;

    // make this a loop so if my homebrew algorithm screws up, we try it again
    do
    {
        // now find all intersection points of line with polyline sides
        npts = 0;
        for( int icont = 0; icont<GetNumContours(); icont++ )
        {
            int istart = GetContourStart( icont );
            int iend   = GetContourEnd( icont );
            for( int ic = istart; ic<=iend; ic++ )
            {
                double x, y, x2, y2;
                int    ok;
                if( ic == istart )
                    ok = FindLineSegmentIntersection( a, slope,
                                                      corner[iend].x, corner[iend].y,
                                                      corner[istart].x, corner[istart].y,
                                                      side_style[corner.size() - 1],
                                                      &x, &y, &x2, &y2 );
                else
                    ok = FindLineSegmentIntersection( a, slope,
                                                      corner[ic - 1].x, corner[ic - 1].y,
                                                      corner[ic].x, corner[ic].y,
                                                      side_style[ic - 1],
                                                      &x, &y, &x2, &y2 );
                if( ok )
                {
                    xx[npts] = (int) x;
                    yy[npts] = (int) y;
                    npts++;
                    wxASSERT( npts<MAXPTS );    // overflow
                }
                if( ok == 2 )
                {
                    xx[npts] = (int) x2;
                    yy[npts] = (int) y2;
                    npts++;
                    wxASSERT( npts<MAXPTS );    // overflow
                }
            }
        }

        nloops++;
        a += PCBU_PER_MIL / 100;
    } while( npts % 2 != 0 && nloops < 3 );

    wxASSERT( npts % 2==0 );  // odd number of intersection points, error

    // count intersection points to right of (x,y), if odd (x,y) is inside polyline
    int ncount = 0;
    for( int ip = 0; ip<npts; ip++ )
    {
        if( xx[ip] == x && yy[ip] == y )
            return FALSE; // (x,y) is on a side, call it outside
        else if( xx[ip] > x )
            ncount++;
    }

    if( ncount % 2 )
        return TRUE;
    else
        return FALSE;
}


// test to see if a point is inside polyline contour
//
bool CPolyLine::TestPointInsideContour( int icont, int x, int y )
{
    if( icont >= GetNumContours() )
        return FALSE;

    enum {
        MAXPTS = 100
    };
    if( !GetClosed() )
        wxASSERT( 0 );

    // define line passing through (x,y), with slope = 2/3;
    // get intersection points
    double xx[MAXPTS], yy[MAXPTS];
    double slope = (double) 2.0 / 3.0;
    double a      = y - slope * x;
    int    nloops = 0;
    int    npts;

    // make this a loop so if my homebrew algorithm screws up, we try it again
    do
    {
        // now find all intersection points of line with polyline sides
        npts = 0;
        int istart = GetContourStart( icont );
        int iend   = GetContourEnd( icont );
        for( int ic = istart; ic<=iend; ic++ )
        {
            double x, y, x2, y2;
            int    ok;
            if( ic == istart )
                ok = FindLineSegmentIntersection( a, slope,
                                                  corner[iend].x, corner[iend].y,
                                                  corner[istart].x, corner[istart].y,
                                                  side_style[corner.size() - 1],
                                                  &x, &y, &x2, &y2 );
            else
                ok = FindLineSegmentIntersection( a, slope,
                                                  corner[ic - 1].x, corner[ic - 1].y,
                                                  corner[ic].x, corner[ic].y,
                                                  side_style[ic - 1],
                                                  &x, &y, &x2, &y2 );
            if( ok )
            {
                xx[npts] = (int) x;
                yy[npts] = (int) y;
                npts++;
                wxASSERT( npts<MAXPTS );    // overflow
            }
            if( ok == 2 )
            {
                xx[npts] = (int) x2;
                yy[npts] = (int) y2;
                npts++;
                wxASSERT( npts<MAXPTS );    // overflow
            }
        }

        nloops++;
        a += PCBU_PER_MIL / 100;
    } while( npts % 2 != 0 && nloops < 3 );

    wxASSERT( npts % 2==0 );  // odd number of intersection points, error

    // count intersection points to right of (x,y), if odd (x,y) is inside polyline
    int ncount = 0;
    for( int ip = 0; ip<npts; ip++ )
    {
        if( xx[ip] == x && yy[ip] == y )
            return FALSE; // (x,y) is on a side, call it outside
        else if( xx[ip] > x )
            ncount++;
    }

    if( ncount % 2 )
        return TRUE;
    else
        return FALSE;
}


// copy data from another poly, but don't draw it
//
void CPolyLine::Copy( CPolyLine* src )
{
    Undraw();

    // copy corners
    for( unsigned ii = 0; ii < src->corner.size(); ii++ )
        corner.push_back( src->corner[ii] );

    // copy side styles
    for( unsigned ii = 0; ii < src->side_style.size(); ii++ )
        side_style.push_back( src->side_style[ii] );
}


/*******************************************/
bool CPolyLine::IsCutoutContour( int icont )
/*******************************************/

/*
 * return true if the corner icont is inside the outline (i.e it is a hole)
 */
{
    int ncont = GetContour( icont );

    if( ncont == 0 )  // the first contour is the main outline, not an hole
        return false;
    return true;
}


void CPolyLine::MoveOrigin( int x_off, int y_off )
{
    Undraw();
    for( int ic = 0; ic < GetNumCorners(); ic++ )
    {
        SetX( ic, GetX( ic ) + x_off );
        SetY( ic, GetY( ic ) + y_off );
    }

    Draw();
}


// Set various parameters:
//   the calling function should Undraw() before calling them,
//   and Draw() after
//
void CPolyLine::SetX( int ic, int x )
{
    corner[ic].x = x;
}


void CPolyLine::SetY( int ic, int y )
{
    corner[ic].y = y;
}


void CPolyLine::SetEndContour( int ic, bool end_contour )
{
    corner[ic].end_contour = end_contour;
}


// Create CPolyLine for a pad
//
CPolyLine* CPolyLine::MakePolylineForPad( int type, int x, int y, int w, int l, int r, int angle )
{
    CPolyLine* poly = new CPolyLine;
    int        dx   = l / 2;
    int        dy   = w / 2;

    if( angle % 180 == 90 )
    {
        dx = w / 2;
        dy = l / 2;
    }
    if( type == PAD_ROUND )
    {
        poly->Start( 0, x - dx, y, 0 );
        poly->AppendCorner( x, y + dy, ARC_CW, 0 );
        poly->AppendCorner( x + dx, y, ARC_CW, 0 );
        poly->AppendCorner( x, y - dy, ARC_CW, 0 );
        poly->Close( ARC_CW );
    }
    return poly;
}


// Add cutout for a pad
// Convert arcs to multiple straight lines
// Do NOT draw or undraw
//
void CPolyLine::AddContourForPadClearance( int  type,
                                           int  x,
                                           int  y,
                                           int  w,
                                           int  l,
                                           int  r,
                                           int  angle,
                                           int  fill_clearance,
                                           int  hole_w,
                                           int  hole_clearance,
                                           bool bThermal,
                                           int  spoke_w )
{
    int dx = l / 2;
    int dy = w / 2;

    if( angle % 180 == 90 )
    {
        dx = w / 2;
        dy = l / 2;
    }
    int x_clearance = max( fill_clearance, hole_clearance + hole_w / 2 - dx );
    int y_clearance = max( fill_clearance, hole_clearance + hole_w / 2 - dy );
    dx += x_clearance;
    dy += y_clearance;
    if( !bThermal )
    {
        // normal clearance
        if( type == PAD_ROUND || (type == PAD_NONE && hole_w > 0) )
        {
            AppendCorner( x - dx, y, ARC_CW, 0 );
            AppendCorner( x, y + dy, ARC_CW, 0 );
            AppendCorner( x + dx, y, ARC_CW, 0 );
            AppendCorner( x, y - dy, ARC_CW, 0 );
            Close( ARC_CW );
        }
        else if( type == PAD_SQUARE || type == PAD_RECT
                 || type == PAD_RRECT || type == PAD_OVAL )
        {
            AppendCorner( x - dx, y - dy, STRAIGHT, 0 );
            AppendCorner( x + dx, y - dy, STRAIGHT, 0 );
            AppendCorner( x + dx, y + dy, STRAIGHT, 0 );
            AppendCorner( x - dx, y + dy, STRAIGHT, 0 );
            Close( STRAIGHT );
        }
    }
    else
    {
        // thermal relief
        if( type == PAD_ROUND || (type == PAD_NONE && hole_w > 0) )
        {
            // draw 4 "wedges"
            double r = max( w / 2 + fill_clearance, hole_w / 2 + hole_clearance );
            double start_angle = asin( spoke_w / (2.0 * r) );
            double th1, th2, corner_x, corner_y;
            th1 = th2 = corner_x = corner_y = 0; // gcc warning fix
            for( int i = 0; i<4; i++ )
            {
                if( i == 0 )
                {
                    corner_x = spoke_w / 2;
                    corner_y = spoke_w / 2;
                    th1 = start_angle;
                    th2 = pi / 2.0 - start_angle;
                }
                else if( i == 1 )
                {
                    corner_x = -spoke_w / 2;
                    corner_y = spoke_w / 2;
                    th1 = pi / 2.0 + start_angle;
                    th2 = pi - start_angle;
                }
                else if( i == 2 )
                {
                    corner_x = -spoke_w / 2;
                    corner_y = -spoke_w / 2;
                    th1 = -pi + start_angle;
                    th2 = -pi / 2.0 - start_angle;
                }
                else if( i == 3 )
                {
                    corner_x = spoke_w / 2;
                    corner_y = -spoke_w / 2;
                    th1 = -pi / 2.0 + start_angle;
                    th2 = -start_angle;
                }
                AppendCorner( to_int( x + corner_x ), to_int( y + corner_y ), STRAIGHT, 0 );
                AppendCorner( to_int( x + r * cos( th1 ) ), to_int( y + r * sin(
                                                                       th1 ) ), STRAIGHT, 0 );
                AppendCorner( to_int( x + r * cos( th2 ) ), to_int( y + r * sin(
                                                                       th2 ) ), ARC_CCW, 0 );
                Close( STRAIGHT );
            }
        }
        else if( type == PAD_SQUARE || type == PAD_RECT
                 || type == PAD_RRECT || type == PAD_OVAL )
        {
            // draw 4 rectangles
            int xL = x - dx;
            int xR = x - spoke_w / 2;
            int yB = y - dy;
            int yT = y - spoke_w / 2;
            AppendCorner( xL, yB, STRAIGHT, 0 );
            AppendCorner( xR, yB, STRAIGHT, 0 );
            AppendCorner( xR, yT, STRAIGHT, 0 );
            AppendCorner( xL, yT, STRAIGHT, 0 );
            Close( STRAIGHT );
            xL = x + spoke_w / 2;
            xR = x + dx;
            AppendCorner( xL, yB, STRAIGHT, 0 );
            AppendCorner( xR, yB, STRAIGHT, 0 );
            AppendCorner( xR, yT, STRAIGHT, 0 );
            AppendCorner( xL, yT, STRAIGHT, 0 );
            Close( STRAIGHT );
            xL = x - dx;
            xR = x - spoke_w / 2;
            yB = y + spoke_w / 2;
            yT = y + dy;
            AppendCorner( xL, yB, STRAIGHT, 0 );
            AppendCorner( xR, yB, STRAIGHT, 0 );
            AppendCorner( xR, yT, STRAIGHT, 0 );
            AppendCorner( xL, yT, STRAIGHT, 0 );
            Close( STRAIGHT );
            xL = x + spoke_w / 2;
            xR = x + dx;
            AppendCorner( xL, yB, STRAIGHT, 0 );
            AppendCorner( xR, yB, STRAIGHT, 0 );
            AppendCorner( xR, yT, STRAIGHT, 0 );
            AppendCorner( xL, yT, STRAIGHT, 0 );
            Close( STRAIGHT );
        }
    }
    return;
}


void CPolyLine::AppendArc( int xi, int yi, int xf, int yf, int xc, int yc, int num )
{
    // get radius
    double r = sqrt( (double) (xi - xc) * (xi - xc) + (double) (yi - yc) * (yi - yc) );

    // get angles of start and finish
    double th_i  = atan2( (double) yi - yc, (double) xi - xc );
    double th_f  = atan2( (double) yf - yc, (double) xf - xc );
    double th_d  = (th_f - th_i) / (num - 1);
    double theta = th_i;

    // generate arc
    for( int ic = 0; ic<num; ic++ )
    {
        int x = to_int( xc + r * cos( theta ) );
        int y = to_int( yc + r * sin( theta ) );
        AppendCorner( x, y, STRAIGHT, 0 );
        theta += th_d;
    }

    Close( STRAIGHT );
}