BOOL PointInPolygon(const CBCGPPointsArray& arPoly, const CBCGPPoint& pt)
{
int nSize = (int)arPoly.GetSize ();
if (nSize < 3)
{
return FALSE;
}
const CBCGPPoint* pData = arPoly.GetData();
int count = 0;
int current = 0;
int next = 1;
while(next < nSize)
{
BOOL b = (pData[next].y <= pt.y);
if (pData[current].y <= pt.y)
{
b = !b;
}
if (b)
{
if(((pData[next].x - pData[current].x) * (pt.y - pData[current].y) /
(pData[next].y - pData[current].y)) <= (pt.x - pData[current].x))
{
count++;
}
}
current++;
next++;
}
if (pData[0] != pData[nSize - 1])
{
current = nSize - 1;
next = 0;
BOOL b = (pData[next].y <= pt.y);
if (pData[current].y <= pt.y)
{
b = !b;
}
if (b)
{
if(((pData[next].x - pData[current].x) * (pt.y - pData[current].y) /
(pData[next].y - pData[current].y)) <= (pt.x - pData[current].x))
{
count++;
}
}
}
return (count & 1) ? TRUE : FALSE;
}
void CBCGPVector4::CalcPlane(const CBCGPPointsArray& arPoints)
{
int i;
const CBCGPPoint* pData = arPoints.GetData();
if (pData == NULL)
{
return;
}
CBCGPMatrix4x4 mA;
for (i = 0; i < 3; i++)
{
mA[i][0] = 1.;
mA[i][1] = pData[i].y;
mA[i][2] = pData[i].z;
}
CBCGPMatrix4x4 mB;
for (i = 0; i < 3; i++)
{
mB[i][0] = pData[i].x;
mB[i][1] = 1.;
mB[i][2] = pData[i].z;
}
CBCGPMatrix4x4 mC;
for (i = 0; i < 3; i++)
{
mC[i][0] = pData[i].x;
mC[i][1] = pData[i].y;
mC[i][2] = 1.;
}
CBCGPMatrix4x4 mD;
for (i = 0; i < 3; i++)
{
mD[i][0] = pData[i].x;
mD[i][1] = pData[i].y;
mD[i][2] = pData[i].z;
}
m_data[0] = mA.Det(3);
m_data[1] = mB.Det(3);
m_data[2] = mC.Det(3);
m_data[3] = -mD.Det(3);
}
int FindPointInPolygon(const CBCGPPointsArray& arPoly, const CBCGPPoint& pt)
{
int nSize = (int)arPoly.GetSize ();
if (nSize == 0)
{
return -1;
}
int index = -1;
const CBCGPPoint* pData = arPoly.GetData();
for (int i = 0; i < nSize; i++)
{
if (pData[i].x == pt.x && pData[i].y == pt.y)
{
index = i;
break;
}
}
return index;
}
BOOL BCGPCalculateIntersectPoint(const CBCGPPointsArray& arPoly1, const CBCGPPointsArray& arPoly2,
CBCGPPoint& ptIntersect)
{
int nPoly1Size = (int)arPoly1.GetSize();
int nPoly2Size = (int)arPoly2.GetSize();
if (nPoly1Size == 0 || nPoly2Size == 0)
{
return FALSE;
}
const CBCGPPoint* pData1 = arPoly1.GetData ();
const CBCGPPoint* pData2 = arPoly2.GetData ();
CBCGPPointsArray arPolyRes;
arPolyRes.SetSize (0, nPoly1Size + nPoly2Size);
int i = 0;
int j = 0;
// 1. find all points from arPoly1F in arPoly2F
int nSize1 = 0;
for (i = 0; i < nPoly1Size; i++)
{
const CBCGPPoint& pt = pData1[i];
if (PointInPolygon (arPoly2, pt))
{
if (AddPointInPolygon(arPolyRes, pt))
{
nSize1++;
}
}
}
// all points in arPoly2F
if (nSize1 != nPoly1Size)
{
// 2. find all points from arPoly2F in arPoly1F
int nSize2 = 0;
for (i = 0; i < nPoly2Size; i++)
{
const CBCGPPoint& pt = pData2[i];
if (PointInPolygon (arPoly1, pt))
{
if (AddPointInPolygon(arPolyRes, pt))
{
nSize2++;
}
}
}
// all points in arPoly1F
if (nSize1 != 0 || nSize2 != nPoly2Size)
{
// 3. find all intersection points arPoly1F and arPoly2F
for (i = 0; i < nPoly1Size; i++)
{
const CBCGPPoint& ptStart1 = pData1[i];
const CBCGPPoint& ptEnd1 = pData1[(i + 1) % nPoly1Size];
for (j = 0; j < nPoly2Size; j++)
{
const CBCGPPoint& ptStart2 = pData2[j];
const CBCGPPoint& ptEnd2 = pData2[(j + 1) % nPoly2Size];
if (bcgp_classify_point2D(ptStart1, ptEnd1, ptStart2) !=
bcgp_classify_point2D(ptStart1, ptEnd1, ptEnd2))
{
CBCGPPoint pt;
if (BCGPIntersectPoints2D (ptStart1, ptEnd1, ptStart2, ptEnd2, pt))
{
AddPointInPolygon(arPolyRes, pt);
}
}
}
}
}
}
int nSize = (int)arPolyRes.GetSize();
if (nSize < 2)
{
return FALSE;
}
ptIntersect.x = 0.0;
ptIntersect.y = 0.0;
for (i = 0; i < nSize; i++)
{
ptIntersect += arPolyRes[i];
}
ptIntersect /= nSize;
return TRUE;
}
