private static Point3D[] TwoInside(ITriangleIndexed[] hull, ITriangle triangle, int insidePointIndex1, int insidePointIndex2)
{
if (insidePointIndex1 > insidePointIndex2)
{
// Reverse them to simplify the switch statements
return TwoInside(hull, triangle, insidePointIndex2, insidePointIndex1);
}
#region Examine Indices
TriangleEdge edgeLeft, edgeRight;
Point3D insidePointLeft, insidePointRight, insidePointMiddle, outsideCenterPoint;
switch (insidePointIndex1)
{
case 0:
switch (insidePointIndex2)
{
case 1:
#region 0, 1
edgeLeft = TriangleEdge.Edge_20;
edgeRight = TriangleEdge.Edge_12;
insidePointLeft = triangle.Point0;
insidePointRight = triangle.Point1;
insidePointMiddle = triangle.GetEdgeMidpoint(TriangleEdge.Edge_01);
outsideCenterPoint = triangle.Point2;
#endregion
break;
case 2:
#region 0, 2
edgeLeft = TriangleEdge.Edge_01;
edgeRight = TriangleEdge.Edge_12;
insidePointLeft = triangle.Point0;
insidePointRight = triangle.Point2;
insidePointMiddle = triangle.GetEdgeMidpoint(TriangleEdge.Edge_20);
outsideCenterPoint = triangle.Point1;
#endregion
break;
default:
throw new ApplicationException("Unexpected point: " + insidePointIndex2.ToString());
}
break;
case 1:
#region 1, 2
if (insidePointIndex2 != 2)
{
throw new ApplicationException("Unexpected point: " + insidePointIndex2.ToString());
}
edgeLeft = TriangleEdge.Edge_01;
edgeRight = TriangleEdge.Edge_20;
insidePointLeft = triangle.Point1;
insidePointRight = triangle.Point2;
insidePointMiddle = triangle.GetEdgeMidpoint(TriangleEdge.Edge_12);
outsideCenterPoint = triangle.Point0;
#endregion
break;
default:
throw new ApplicationException("Unexpected point: " + insidePointIndex2.ToString());
}
// Make sure that outsideCenterPoint is outside the hull
outsideCenterPoint = EnsureOutsidePointIsBeyondHull(hull[0].AllPoints, insidePointMiddle, outsideCenterPoint);
#endregion
// Get edge/hull intersections
var intersectLeft = GetIntersectPoints(hull, triangle.GetPoint(edgeLeft, true), triangle.GetPoint(edgeLeft, false));
if (intersectLeft.Length == 0)
{
return null; // triangle is only touching the hull, not really intersecting
}
var intersectRight = GetIntersectPoints(hull, triangle.GetPoint(edgeRight, true), triangle.GetPoint(edgeRight, false));
if (intersectRight.Length == 0)
{
return null;
}
// Now that the two intersect points are found, find connecting lines
Point3D[] hullEdge = GetConnectingLines(hull, intersectLeft[0], intersectRight[0], outsideCenterPoint);
// Clip poly
List<Point3D> hullPoly = new List<Point3D>();
hullPoly.Add(insidePointLeft);
hullPoly.AddRange(hullEdge);
hullPoly.Add(insidePointRight);
Point3D[] retVal = Math2D.GetIntersection_Polygon_Triangle(hullPoly.ToArray(), triangle);
// Exit Function
return retVal;
}
private static Point3D[] OneInside(ITriangleIndexed[] hull, ITriangle triangle, int insidePointIndex)
{
#region Examine Index
TriangleEdge edge1, edge2, edgeOutside; // Edges that are intersecting the hull
Point3D insidePoint, outsideCenterPoint;
switch (insidePointIndex)
{
case 0:
edge1 = TriangleEdge.Edge_01;
edge2 = TriangleEdge.Edge_20;
edgeOutside = TriangleEdge.Edge_12;
insidePoint = triangle.Point0;
outsideCenterPoint = triangle.GetEdgeMidpoint(edgeOutside);
break;
case 1:
edge1 = TriangleEdge.Edge_01;
edge2 = TriangleEdge.Edge_12;
edgeOutside = TriangleEdge.Edge_20;
insidePoint = triangle.Point1;
outsideCenterPoint = triangle.GetEdgeMidpoint(edgeOutside);
break;
case 2:
edge1 = TriangleEdge.Edge_12;
edge2 = TriangleEdge.Edge_20;
edgeOutside = TriangleEdge.Edge_01;
insidePoint = triangle.Point2;
outsideCenterPoint = triangle.GetEdgeMidpoint(edgeOutside);
break;
default:
throw new ApplicationException("Unexpected point: " + insidePointIndex.ToString());
}
// Make sure that outsideCenterPoint is outside the hull
outsideCenterPoint = EnsureOutsidePointIsBeyondHull(hull[0].AllPoints, insidePoint, outsideCenterPoint);
#endregion
// Get edge/hull intersections
var intersect1 = GetIntersectPoints(hull, triangle.GetPoint(edge1, true), triangle.GetPoint(edge1, false));
if (intersect1.Length == 0)
{
return null; // triangle is only touching the hull, not really intersecting
}
else if (intersect1.Length > 1)
{
throw new ApplicationException("Should never get more than one intersect point: " + intersect1.Length.ToString());
}
var intersect2 = GetIntersectPoints(hull, triangle.GetPoint(edge2, true), triangle.GetPoint(edge2, false));
if (intersect2.Length == 0)
{
return null;
}
else if (intersect2.Length > 1)
{
throw new ApplicationException("Should never get more than one intersect point: " + intersect2.Length.ToString());
}
// Now that the two intersect points are found, find connecting lines
Point3D[] hullEdge = GetConnectingLines(hull, intersect1[0], intersect2[0], outsideCenterPoint);
// Clip poly
List<Point3D> hullPoly = new List<Point3D>();
hullPoly.Add(insidePoint);
hullPoly.AddRange(hullEdge);
Point3D[] retVal = Math2D.GetIntersection_Polygon_Triangle(hullPoly.ToArray(), triangle);
// Exit Function
return retVal;
}
