#include "stdafx.h"

int XOsEnd(XPoint &ptPick, DList<XCurveSegment> &lstCurves)
{
   for(int i=0; i<lstCurves.Length(); i++) {
      XCurveSegment &curve=*lstCurves[i];
      if(curve.OSnap(OS_END, ptPick))
         return OS_END;
   }
   return OS_NON;
}

int XOsMid(XPoint &ptPick, DList<XCurveSegment> &lstCurves)
{
   for(int i=0; i<lstCurves.Length(); i++) {
      XCurveSegment &curve=*lstCurves[i];
      if(curve.OSnap(OS_MID, ptPick))
         return OS_MID;
   }
   return OS_NON;
}


int XOsInt(XPoint &ptPick, DList<XCurveSegment> &lstCurves)
{
   int len=lstCurves.Length();
   for(int i=0; i<len; i++) {
      XCurveSegment &curve1=*lstCurves[i];
      for(int j=i+1; j<len; j++) {
         XCurveSegment &curve2=*lstCurves[j];
         XPoint pt1, pt2;
         int nInt=curve1.Intersection(curve2, pt1, pt2);
         if(nInt==1) {
            ptPick=pt1;
            return OS_INT;
         } else if(nInt==2) {
            ptPick = XLine(pt1,pt2).NearPoint(ptPick);
            return OS_INT;
         }
      }
   }
   return OS_NON;
}


int XOsNea(XPoint &ptPick, DList<XCurveSegment> &lstCurves)
{
   for(int i=0; i<lstCurves.Length(); i++) {
      XCurveSegment &curve=*lstCurves[i];
      if(curve.OSnap(OS_NEA, ptPick))
         return OS_NEA;
   }
   return OS_NON;
}


int XOsnap(XPoint &ptPick, int nMode, DList<XCurveSegment> &ss)
{
   switch(nMode) {
   case OS_END: return XOsEnd(ptPick, ss);
   case OS_MID: return XOsMid(ptPick, ss);
   case OS_INT: return XOsInt(ptPick, ss);
   case OS_NEA: return XOsNea(ptPick, ss);
   }
   return OS_NON;
}



// return: the mode has been use
// Now: 
//      ptPick1(WCS) -- both IN/OUT
//      mask--support LINE,ARC,CIRCLE
//      mode--support END, MID, INT, NEA
//      nHalfSize--The aperture half size, when <=0, use last size
//      bInsideAperture -- Make sure the Osnap point must inside the aperture
//      bPrio -- 0 Descendent mode,  1 Ascendent
TUTIL_IMPEXP int XOsnap(XPoint &ptPick1, int nMode, const RBList &rbMask, ads_real nHalfSize, int bInsideAperture, int bPrior)
{
   static ads_real nHalfAperture=10.0;
   if(nHalfSize>0.0) nHalfAperture=nHalfSize;
   XPoint ptPick=ptPick1;
   XPoint ptLow=Wcs2Ucs(ptPick)-XPoint(nHalfAperture, nHalfAperture),
          ptUp=Wcs2Ucs(ptPick)+XPoint(nHalfAperture, nHalfAperture);
   PickSet ss(SS_FREE);
   if(ss.Get(_T("C"), ptLow, ptUp, rbMask)!=RTNORM)
      return OS_NON;

   DList<XCurveSegment> lstCurves;
   long ssLen=ss.Length();
   for(long n=0; n<ssLen; n++) {
      Entity ent=ss[n];
      XCurveSegment *seg=new XCurveSegment(ent, LS_FINITE);
      if(!(*seg)) {
         delete seg;
      } else {
         lstCurves.Append(seg);
      }
   }

   XRectAngle boxTarget(ptLow, ptUp);
   int nModeArray[]={OS_END, OS_MID, OS_INT, OS_NEA};
   int nIndex=bPrior? 0:(ELEMENTS(nModeArray)-1);
   for(int i=0; i<ELEMENTS(nModeArray); i++) {
      if(nMode&nModeArray[nIndex]) {
         if(XOsnap(ptPick, nModeArray[nIndex], lstCurves)) {
            if(!bInsideAperture || (Wcs2Ucs(ptPick)&boxTarget)==PR_INSIDE) {
               ptPick1=ptPick;
               return nModeArray[nIndex];
            }
         }
      }
      if(bPrior)  nIndex++;
      else nIndex--;
   }
   return OS_NON;
}