// A parent is a shape which fully contains another shape
public bool IsParentOf(CompositeShapeData otherShape)
{
if (otherShape.parents.Contains(this))
{
return(true);
}
if (parents.Contains(otherShape))
{
return(false);
}
// check if first point in otherShape is inside this shape. If not, parent test fails.
// if yes, then continue to line seg intersection test between the two shapes
// (this point test is important because without it, if all line seg intersection tests fail,
// we wouldn't know if otherShape is entirely inside or entirely outside of this shape)
bool pointInsideShape = false;
for (int i = 0; i < triangles.Length; i += 3)
{
if (Maths2D.PointInTriangle(polygon.points[triangles[i]], polygon.points[triangles[i + 1]], polygon.points[triangles[i + 2]], otherShape.points[0]))
{
pointInsideShape = true;
break;
}
}
if (!pointInsideShape)
{
return(false);
}
// Check for intersections between line segs of this shape and otherShape (any intersections will fail the parent test)
for (int i = 0; i < points.Length; i++)
{
LineSegment parentSeg = new LineSegment(points[i], points[(i + 1) % points.Length]);
for (int j = 0; j < otherShape.points.Length; j++)
{
LineSegment childSeg = new LineSegment(otherShape.points[j], otherShape.points[(j + 1) % otherShape.points.Length]);
if (Maths2D.LineSegmentsIntersect(parentSeg.a, parentSeg.b, childSeg.a, childSeg.b))
{
return(false);
}
}
}
return(true);
}
// Test if the shapes overlap partially (test will fail if one shape entirely contains other shape, i.e. one is parent of the other).
public bool OverlapsPartially(CompositeShapeData otherShape)
{
// Check for intersections between line segs of this shape and otherShape (any intersection will validate the overlap test)
for (int i = 0; i < points.Length; i++)
{
LineSegment segA = new LineSegment(points[i], points[(i + 1) % points.Length]);
for (int j = 0; j < otherShape.points.Length; j++)
{
LineSegment segB = new LineSegment(otherShape.points[j], otherShape.points[(j + 1) % otherShape.points.Length]);
if (Maths2D.LineSegmentsIntersect(segA.a, segA.b, segB.a, segB.b))
{
return(true);
}
}
}
return(false);
}
// Checks if any of the line segments making up this shape intersect
public bool IntersectsWithSelf()
{
for (int i = 0; i < points.Length; i++)
{
LineSegment segA = new LineSegment(points[i], points[(i + 1) % points.Length]);
for (int j = i + 2; j < points.Length; j++)
{
if ((j + 1) % points.Length == i)
{
continue;
}
LineSegment segB = new LineSegment(points[j], points[(j + 1) % points.Length]);
if (Maths2D.LineSegmentsIntersect(segA.a, segA.b, segB.a, segB.b))
{
return(true);
}
}
}
return(false);
}