/// <summary>
/// Builds required crossing data.
/// </summary>
/// <param name="crossings">The crossings to calculate. (Note: collection is modified)</param>
/// <param name="a">The left hand polygon.</param>
/// <param name="b">The right hand polygon.</param>
private PolygonCrossingsAlgorithmKernel CreateIntersectionKernelFromCrossings(List <PolygonCrossing> crossings, Polygon2 a, Polygon2 b)
{
Contract.Requires(crossings != null);
Contract.Requires(a != null);
Contract.Requires(b != null);
Contract.Ensures(Contract.Result <PolygonCrossingsAlgorithmKernel>() != null);
var kernel = new PolygonCrossingsAlgorithmKernel(a, b, crossings);
if (crossings.Count == 0)
{
return(kernel);
}
foreach (var currentCrossing in crossings)
{
var ringIndexA = currentCrossing.LocationA.RingIndex;
Contract.Assume(ringIndexA < a.Count);
var ringA = a[ringIndexA];
Contract.Assume(ringA != null);
var crossingsOnRingA = kernel.RingCrossingsA.Get(ringIndexA);
var priorPointA = FindPreviousRingPoint(currentCrossing, crossingsOnRingA, ringA, GetLocationA, PolygonCrossing.LocationAComparer.Default);
var nextPointA = FindNextRingPoint(currentCrossing, crossingsOnRingA, ringA, GetLocationA, PolygonCrossing.LocationAComparer.Default);
var ringIndexB = currentCrossing.LocationB.RingIndex;
Contract.Assume(ringIndexB < b.Count);
var ringB = b[ringIndexB];
Contract.Assume(ringB != null);
var crossingsOnRingB = kernel.RingCrossingsB.Get(ringIndexB);
var priorPointB = FindPreviousRingPoint(currentCrossing, crossingsOnRingB, ringB, GetLocationB, PolygonCrossing.LocationBComparer.Default);
var nextPointB = FindNextRingPoint(currentCrossing, crossingsOnRingB, ringB, GetLocationB, PolygonCrossing.LocationBComparer.Default);
// based on the vectors, need to classify the crossing type
currentCrossing.CrossType = PolygonCrossing.DetermineCrossingType(
(nextPointA - currentCrossing.Point).GetNormalized(),
(priorPointA - currentCrossing.Point).GetNormalized(),
(nextPointB - currentCrossing.Point).GetNormalized(),
(priorPointB - currentCrossing.Point).GetNormalized()
);
}
foreach (var ringCrossings in kernel.RingCrossingsA.RingCrossings)
{
Contract.Assume(ringCrossings.Key >= 0 && ringCrossings.Key < a.Count);
if (a[ringCrossings.Key].FillSide == RelativeDirectionType.Right)
{
foreach (var crossing in ringCrossings.Value)
{
Contract.Assume(crossing != null);
var crossLegType = crossing.CrossType & CrossingType.Parallel;
if (crossLegType == CrossingType.CrossToRight || crossLegType == CrossingType.DivergeRight)
{
kernel.Entrances.Add(crossing);
}
else if (crossLegType == CrossingType.CrossToLeft || crossLegType == CrossingType.ConvergeRight)
{
kernel.Exits.Add(crossing);
}
}
}
else
{
foreach (var crossing in ringCrossings.Value)
{
Contract.Assume(crossing != null);
var crossLegType = crossing.CrossType & CrossingType.Parallel;
if (crossLegType == CrossingType.CrossToLeft || crossLegType == CrossingType.DivergeLeft)
{
kernel.Entrances.Add(crossing);
}
else if (crossLegType == CrossingType.CrossToRight || crossLegType == CrossingType.ConvergeLeft)
{
kernel.Exits.Add(crossing);
}
}
}
}
var sortedEntrances = kernel.Entrances.ToArray();
Array.Sort(sortedEntrances, PolygonCrossing.LocationAComparer.CompareNonNull);
Contract.Assume(kernel.Exits != null);
var sortedExits = kernel.Exits.ToArray();
Array.Sort(sortedExits, PolygonCrossing.LocationBComparer.CompareNonNull);
for (int i = 0; i < sortedExits.Length; i++)
{
var exit = sortedExits[i];
var locationIndex = Array.BinarySearch(sortedEntrances, exit, PolygonCrossing.LocationAComparer.Default);
if (locationIndex >= 0)
{
kernel.ExitHops.Add(exit, sortedEntrances[locationIndex]);
}
}
for (int i = 0; i < sortedEntrances.Length; i++)
{
var entrance = sortedEntrances[i];
var locationIndex = Array.BinarySearch(sortedExits, entrance, PolygonCrossing.LocationBComparer.Default);
if (locationIndex >= 0)
{
kernel.EntranceHops.Add(entrance, sortedExits[locationIndex]);
}
}
return(kernel);
}
/// <summary>
/// Builds required crossing data.
/// </summary>
/// <param name="crossings">The crossings to calculate. (Note: collection is modified)</param>
/// <param name="a">The left hand polygon.</param>
/// <param name="b">The right hand polygon.</param>
private PolygonCrossingsAlgorithmKernel CreateIntersectionKernelFromCrossings(List<PolygonCrossing> crossings, Polygon2 a, Polygon2 b) {
Contract.Requires(crossings != null);
Contract.Requires(a != null);
Contract.Requires(b != null);
Contract.Ensures(Contract.Result<PolygonCrossingsAlgorithmKernel>() != null);
var kernel = new PolygonCrossingsAlgorithmKernel(a, b, crossings);
if (crossings.Count == 0)
return kernel;
foreach (var currentCrossing in crossings) {
var ringIndexA = currentCrossing.LocationA.RingIndex;
Contract.Assume(ringIndexA < a.Count);
var ringA = a[ringIndexA];
Contract.Assume(ringA != null);
var crossingsOnRingA = kernel.RingCrossingsA.Get(ringIndexA);
var priorPointA = FindPreviousRingPoint(currentCrossing, crossingsOnRingA, ringA, GetLocationA, PolygonCrossing.LocationAComparer.Default);
var nextPointA = FindNextRingPoint(currentCrossing, crossingsOnRingA, ringA, GetLocationA, PolygonCrossing.LocationAComparer.Default);
var ringIndexB = currentCrossing.LocationB.RingIndex;
Contract.Assume(ringIndexB < b.Count);
var ringB = b[ringIndexB];
Contract.Assume(ringB != null);
var crossingsOnRingB = kernel.RingCrossingsB.Get(ringIndexB);
var priorPointB = FindPreviousRingPoint(currentCrossing, crossingsOnRingB, ringB, GetLocationB, PolygonCrossing.LocationBComparer.Default);
var nextPointB = FindNextRingPoint(currentCrossing, crossingsOnRingB, ringB, GetLocationB, PolygonCrossing.LocationBComparer.Default);
// based on the vectors, need to classify the crossing type
currentCrossing.CrossType = PolygonCrossing.DetermineCrossingType(
(nextPointA - currentCrossing.Point).GetNormalized(),
(priorPointA - currentCrossing.Point).GetNormalized(),
(nextPointB - currentCrossing.Point).GetNormalized(),
(priorPointB - currentCrossing.Point).GetNormalized()
);
}
foreach (var ringCrossings in kernel.RingCrossingsA.RingCrossings) {
Contract.Assume(ringCrossings.Key >= 0 && ringCrossings.Key < a.Count);
if (a[ringCrossings.Key].FillSide == RelativeDirectionType.Right) {
foreach (var crossing in ringCrossings.Value) {
Contract.Assume(crossing != null);
var crossLegType = crossing.CrossType & CrossingType.Parallel;
if (crossLegType == CrossingType.CrossToRight || crossLegType == CrossingType.DivergeRight)
kernel.Entrances.Add(crossing);
else if (crossLegType == CrossingType.CrossToLeft || crossLegType == CrossingType.ConvergeRight)
kernel.Exits.Add(crossing);
}
}
else {
foreach (var crossing in ringCrossings.Value) {
Contract.Assume(crossing != null);
var crossLegType = crossing.CrossType & CrossingType.Parallel;
if (crossLegType == CrossingType.CrossToLeft || crossLegType == CrossingType.DivergeLeft)
kernel.Entrances.Add(crossing);
else if (crossLegType == CrossingType.CrossToRight || crossLegType == CrossingType.ConvergeLeft)
kernel.Exits.Add(crossing);
}
}
}
var sortedEntrances = kernel.Entrances.ToArray();
Array.Sort(sortedEntrances, PolygonCrossing.LocationAComparer.CompareNonNull);
Contract.Assume(kernel.Exits != null);
var sortedExits = kernel.Exits.ToArray();
Array.Sort(sortedExits, PolygonCrossing.LocationBComparer.CompareNonNull);
for (int i = 0; i < sortedExits.Length; i++) {
var exit = sortedExits[i];
var locationIndex = Array.BinarySearch(sortedEntrances, exit, PolygonCrossing.LocationAComparer.Default);
if(locationIndex >= 0)
kernel.ExitHops.Add(exit, sortedEntrances[locationIndex]);
}
for (int i = 0; i < sortedEntrances.Length; i++) {
var entrance = sortedEntrances[i];
var locationIndex = Array.BinarySearch(sortedExits, entrance, PolygonCrossing.LocationBComparer.Default);
if(locationIndex >= 0)
kernel.EntranceHops.Add(entrance, sortedExits[locationIndex]);
}
return kernel;
}