private ClosePolygonResult FindPolygonPointClosestTo(IntPoint input)
{
ClosePolygonResult ret = new ClosePolygonResult();
for (int n = 0; n < PolygonList.Count; n++)
{
IntPoint p0 = PolygonList[n][PolygonList[n].Count - 1];
for (int i = 0; i < PolygonList[n].Count; i++)
{
IntPoint p1 = PolygonList[n][i];
//Q = A + Normal( B - A ) * ((( B - A ) dot ( P - A )) / VSize( A - B ));
IntPoint pDiff = p1 - p0;
long lineLength = (pDiff).Length();
if (lineLength > 1)
{
long distOnLine = (pDiff).Dot(input - p0) / lineLength;
if (distOnLine >= 0 && distOnLine <= lineLength)
{
IntPoint q = p0 + pDiff * distOnLine / lineLength;
if ((q - input).ShorterThen(100))
{
ret.intersectionPoint = q;
ret.polygonIdx = n;
ret.pointIdx = i;
return(ret);
}
}
}
p0 = p1;
}
}
ret.polygonIdx = -1;
return(ret);
}
private GapCloserResult FindPolygonGapCloser(IntPoint ip0, IntPoint ip1)
{
GapCloserResult ret = new GapCloserResult();
ClosePolygonResult c1 = FindPolygonPointClosestTo(ip0);
ClosePolygonResult c2 = FindPolygonPointClosestTo(ip1);
if (c1.polygonIdx < 0 || c1.polygonIdx != c2.polygonIdx)
{
ret.len = -1;
return(ret);
}
ret.polygonIndex = c1.polygonIdx;
ret.pointIndexA = c1.pointIdx;
ret.pointIndexB = c2.pointIdx;
ret.AtoB = true;
if (ret.pointIndexA == ret.pointIndexB)
{
//Connection points are on the same line segment.
ret.len = (ip0 - ip1).Length();
}
else
{
//Find out if we have should go from A to B or the other way around.
IntPoint p0 = PolygonList[ret.polygonIndex][ret.pointIndexA];
long lenA = (p0 - ip0).Length();
for (int i = ret.pointIndexA; i != ret.pointIndexB; i = (i + 1) % PolygonList[ret.polygonIndex].Count)
{
IntPoint p1 = PolygonList[ret.polygonIndex][i];
lenA += (p0 - p1).Length();
p0 = p1;
}
lenA += (p0 - ip1).Length();
p0 = PolygonList[ret.polygonIndex][ret.pointIndexB];
long lenB = (p0 - ip1).Length();
for (int i = ret.pointIndexB; i != ret.pointIndexA; i = (i + 1) % PolygonList[ret.polygonIndex].Count)
{
IntPoint p1 = PolygonList[ret.polygonIndex][i];
lenB += (p0 - p1).Length();
p0 = p1;
}
lenB += (p0 - ip0).Length();
if (lenA < lenB)
{
ret.AtoB = true;
ret.len = lenA;
}
else
{
ret.AtoB = false;
ret.len = lenB;
}
}
return(ret);
}
private ClosePolygonResult FindPolygonPointClosestTo(IntPoint input)
{
ClosePolygonResult ret = new ClosePolygonResult();
for (int n = 0; n < PolygonList.Count; n++)
{
IntPoint p0 = PolygonList[n][PolygonList[n].Count - 1];
for (int i = 0; i < PolygonList[n].Count; i++)
{
IntPoint p1 = PolygonList[n][i];
//Q = A + Normal( B - A ) * ((( B - A ) dot ( P - A )) / VSize( A - B ));
IntPoint pDiff = p1 - p0;
long lineLength = (pDiff).Length();
if (lineLength > 1)
{
long distOnLine = (pDiff).Dot(input - p0) / lineLength;
if (distOnLine >= 0 && distOnLine <= lineLength)
{
IntPoint q = p0 + pDiff * distOnLine / lineLength;
if ((q - input).ShorterThen(100))
{
ret.intersectionPoint = q;
ret.polygonIdx = n;
ret.pointIdx = i;
return ret;
}
}
}
p0 = p1;
}
}
ret.polygonIdx = -1;
return ret;
}