static internal Point RawIntersection(IntersectionInfo xx, Point origin) {
// If this fires, then you didn't pass the LineSegment as the first argument to GetAllIntersections.
Debug.Assert(xx.Segment0 is LineSegment, "LineSegment was not first arg to GetAllIntersections");
// The intersection snaps the end of the intersection to the PolylinePoint at the start/end
// of the interesecting segment on the obstacle if the intersection is Curve.CloseIntersections
// to that segment endpoint, which can return a point that is just more than Curve.DistanceEpsilon
// off the line. Therefore, re-create the intersection using the LineSegment and intersection
// parameters (this assumes the LineSegment.End is not Curve.CloseIntersections to the intersection).
Point point = xx.Segment0[xx.Par0];
#if DEBUG
// This may legitimately be rounding-error'd in the same way as xx.IntersectionPoint (and the
// caller addresses this later). The purpose of the assert is to verify that the LineSegment
// interception is not outside the bbox in the perpendicular direction.
var lineSeg = (LineSegment)xx.Segment0;
if (StaticGraphUtility.IsVertical(PointComparer.GetDirections(lineSeg.Start, lineSeg.End))) {
Debug.Assert(PointComparer.Equal(point.X, origin.X), "segment0 obstacle intersection is off the vertical line");
}
else {
Debug.Assert(PointComparer.Equal(point.Y, origin.Y), "segment0 obstacle intersection is off the horizontal line");
}
#endif // DEBUG
return ApproximateComparer.Round(point);
}
// Most of the original contents of this file have been subsumed into ObstacleTree and TransientGraphUtility.
internal static Point MungeClosestIntersectionInfo(Point rayOrigin, IntersectionInfo closestIntersection, bool isHorizontal) {
Rectangle bbox = closestIntersection.Segment1.BoundingBox;
#if SHARPKIT //https://code.google.com/p/sharpkit/issues/detail?id=369
Point closest = RawIntersection(closestIntersection, rayOrigin).Clone();
#else
Point closest = RawIntersection(closestIntersection, rayOrigin);
#endif
if (isHorizontal) {
closest.X = MungeIntersect(rayOrigin.X, closest.X, bbox.Left, bbox.Right);
}
else { // vertical
closest.Y = MungeIntersect(rayOrigin.Y, closest.Y, bbox.Bottom, bbox.Top);
}
return closest;
}
internal static IntersectionInfo LiftIntersectionToCurves(ICurve c0, ICurve c1, IntersectionInfo xx) {
return LiftIntersectionToCurves(c0, c1, xx.Par0, xx.Par1, xx.IntersectionPoint, xx.Segment0, xx.Segment1);
}
static void AddIntersection(ParallelogramLeaf n0, ParallelogramLeaf n1, List<IntersectionInfo> intersections,
double aSol, double bSol,
Point x) {
//adjust the intersection if it is close to the ends of the segs
if (ApproximateComparer.CloseIntersections(x, n0.Seg[n0.Low])) {
x = n0.Seg[n0.Low];
aSol = n0.Low;
}
else if (ApproximateComparer.CloseIntersections(x, n0.Seg[n0.High])) {
x = n0.Seg[n0.High];
aSol = n0.High;
}
if (ApproximateComparer.CloseIntersections(x, n1.Seg[n1.Low])) {
x = n1.Seg[n1.Low];
bSol = n1.Low;
}
else if (ApproximateComparer.CloseIntersections(x, n1.Seg[n1.High])) {
x = n1.Seg[n1.High];
bSol = n1.High;
}
bool oldIntersection = OldIntersection(intersections, ref x);
if (!oldIntersection) {
var xx = new IntersectionInfo(aSol, bSol, x, n0.Seg, n1.Seg);
intersections.Add(xx);
}
return;
}
static IntersectionInfo DropIntersectionToSegs(IntersectionInfo xx) {
ICurve seg0;
double par0;
if (xx.Segment0 is Curve)
(xx.Segment0 as Curve).GetSegmentAndParameter(xx.Par0, out par0, out seg0);
else {
par0 = xx.Par0;
seg0 = xx.Segment0;
}
ICurve seg1;
double par1;
if (xx.Segment1 is Curve)
(xx.Segment1 as Curve).GetSegmentAndParameter(xx.Par1, out par1, out seg1);
else {
par1 = xx.Par1;
seg1 = xx.Segment1;
}
return new IntersectionInfo(par0, par1, xx.IntersectionPoint, seg0, seg1);
}
static bool AlreadyInside(List<IntersectionInfo> ret, IntersectionInfo intersectionInfo) {
for(int i=0;i<ret.Count;i++) {
var ii = ret[i];
if (ApproximateComparer.CloseIntersections(ii.IntersectionPoint, intersectionInfo.IntersectionPoint))
return true;
}
return false;
}
public static bool RealCut(IntersectionInfo xx, Curve polyline, bool onlyFromInsideCuts) {
ValidateArg.IsNotNull(xx, "xx");
ValidateArg.IsNotNull(polyline, "polyline");
ICurve sseg = xx.Segment0;
ICurve pseg = xx.Segment1;
double spar = xx.Par0;
double ppar = xx.Par1;
Point x = xx.IntersectionPoint;
//normalised tangent to spline
Point ts = sseg.Derivative(spar).Normalize();
Point pn = pseg.Derivative(ppar).Normalize().Rotate(Math.PI/2);
if (ApproximateComparer.Close(x, pseg.End)) {
//so pseg enters the spline
ICurve exitSeg = null;
for (int i = 0; i < polyline.Segments.Count - 1; i++)
if (polyline.Segments[i] == pseg) {
exitSeg = polyline.Segments[i + 1];
break;
}
if (exitSeg == null)
return false; //hit the end of the polyline
Point tsn = ts.Rotate((Math.PI/2));
bool touch = (tsn*pseg.Derivative(pseg.ParEnd))*(tsn*exitSeg.Derivative(exitSeg.ParStart)) <
ApproximateComparer.Tolerance;
return !touch;
}
if (ApproximateComparer.Close(x, pseg.Start)) {
//so pseg exits the spline
ICurve enterSeg = null;
for (int i = polyline.segs.Count - 1; i > 0; i--)
if (polyline.Segments[i] == pseg) {
enterSeg = polyline.Segments[i - 1];
break;
}
if (enterSeg == null)
return false;
Point tsn = ts.Rotate((Math.PI/2));
bool touch = (tsn*pseg.Derivative(pseg.ParStart))*
(tsn*enterSeg.Derivative(enterSeg.ParEnd)) < ApproximateComparer.Tolerance;
return !touch;
}
double d = ts*pn;
if (onlyFromInsideCuts)
return d > ApproximateComparer.DistanceEpsilon;
return Math.Abs(d) > ApproximateComparer.DistanceEpsilon;
}
/// <summary>
/// Returns true if curves do not touch in the intersection point
/// </summary>
/// <param name="xx"></param>
/// <param name="polygon"></param>
/// <param name="onlyFromInsideCuts">if set to true and first curve is closed will return true
/// only when the second curve cuts the first one from the inside</param>
/// <returns></returns>
public static bool RealCutWithClosedCurve(IntersectionInfo xx, Curve polygon, bool onlyFromInsideCuts) {
ValidateArg.IsNotNull(xx, "xx");
ValidateArg.IsNotNull(polygon, "polygon");
ICurve sseg = xx.Segment0;
ICurve pseg = xx.Segment1;
double spar = xx.Par0;
double ppar = xx.Par1;
Point x = xx.IntersectionPoint;
//normalised tangent to spline
Point ts = sseg.Derivative(spar).Normalize();
Point pn = pseg.Derivative(ppar).Normalize().Rotate(Math.PI/2);
if (ApproximateComparer.Close(x, pseg.End)) {
//so pseg enters the spline
ICurve exitSeg = null;
for (int i = 0; i < polygon.Segments.Count; i++)
if (polygon.Segments[i] == pseg) {
exitSeg = polygon.Segments[(i + 1)%polygon.Segments.Count];
break;
}
if (exitSeg == null)
throw new InvalidOperationException(); //"exitSeg==null");
Point tsn = ts.Rotate((Math.PI/2));
bool touch = (tsn*pseg.Derivative(pseg.ParEnd))*(tsn*exitSeg.Derivative(exitSeg.ParStart)) <
ApproximateComparer.Tolerance;
return !touch;
}
if (ApproximateComparer.Close(x, pseg.Start)) {
//so pseg exits the spline
ICurve enterSeg = null;
for (int i = 0; i < polygon.Segments.Count; i++)
if (polygon.Segments[i] == pseg) {
enterSeg = polygon.Segments[i > 0 ? (i - 1) : polygon.Segments.Count - 1];
break;
}
Point tsn = ts.Rotate((Math.PI/2));
bool touch = (tsn*pseg.Derivative(pseg.ParStart))*
(tsn*enterSeg.Derivative(enterSeg.ParEnd)) < ApproximateComparer.Tolerance;
return !touch;
}
double d = ts*pn;
if (onlyFromInsideCuts)
return d > ApproximateComparer.DistanceEpsilon;
return Math.Abs(d) > ApproximateComparer.DistanceEpsilon;
}
static ICurve GetTrimmedCurveForHookingUpAnywhere(ICurve curve, PolylinePoint lastPointInside, IntersectionInfo x0, IntersectionInfo x1) {
var clockwise =
Point.GetTriangleOrientation(x1.IntersectionPoint, x0.IntersectionPoint, lastPointInside.Point) ==
TriangleOrientation.Clockwise;
double rightX = x0.Par0;
double leftX = x1.Par0;
ICurve tr0, tr1;
Curve ret;
if (clockwise) {
if (rightX < leftX)
return curve.Trim(rightX, leftX);
tr0 = curve.Trim(rightX, curve.ParEnd);
tr1 = curve.Trim(curve.ParStart, leftX);
ret = new Curve();
return ret.AddSegs(tr0, tr1);
}
if (leftX < rightX)
return curve.Trim(leftX, rightX);
tr0 = curve.Trim(leftX, curve.ParEnd);
tr1 = curve.Trim(curve.ParStart, rightX);
ret = new Curve();
return ret.AddSegs(tr0, tr1);
}
void ExtendPolyline(Point tangentAtIntersection, IntersectionInfo x, Point polylineTangent, HookUpAnywhereFromInsidePort port) {
var normal=tangentAtIntersection.Rotate(Math.PI/2);
if(normal*polylineTangent<0)
normal=-normal;
var pointBeforeLast = x.IntersectionPoint + normal * port.HookSize;
Point pointAfterX;
if (!Point.LineLineIntersection(pointBeforeLast, pointBeforeLast+tangentAtIntersection, _polyline.End, _polyline.End+polylineTangent, out pointAfterX))
return;
_polyline.AddPoint(pointAfterX);
_polyline.AddPoint(pointBeforeLast);
_polyline.AddPoint(x.IntersectionPoint);
}
