102 lines
3.8 KiB
C#
102 lines
3.8 KiB
C#
|
//
|
||
|
|
// EventQueue.cs
|
||
|
|
// MSAGL class for Rectilinear Edge Routing between two nodes.
|
||
|
|
//
|
||
|
|
// Copyright Microsoft Corporation.
|
||
|
|
|
||
|
|
using System.Collections.Generic;
|
||
|
|
using System.Diagnostics;
|
||
|
|
using Microsoft.Msagl.Core.DataStructures;
|
||
|
|
using Microsoft.Msagl.Routing.Spline.ConeSpanner;
|
||
|
|
using RectRout = Microsoft.Msagl.Routing.Rectilinear;
|
||
|
|
|
||
|
|
namespace Microsoft.Msagl.Routing.Rectilinear {
|
||
|
|
using DebugHelpers;
|
||
|
|
|
||
|
|
/// <summary>
|
||
|
|
/// Wrap the tree of events.
|
||
|
|
/// </summary>
|
||
|
|
internal class EventQueue : IComparer<SweepEvent> {
|
||
|
|
ScanDirection scanDirection;
|
||
|
|
readonly BinaryHeapWithComparer<SweepEvent> eventTree;
|
||
|
|
|
||
|
|
internal EventQueue() {
|
||
|
|
eventTree = new BinaryHeapWithComparer<SweepEvent>(this);
|
||
|
|
}
|
||
|
|
|
||
|
|
internal void Reset(ScanDirection scanDir) {
|
||
|
|
Debug.Assert(0 == eventTree.Count, "Stray events in EventQueue.Reset");
|
||
|
|
scanDirection = scanDir;
|
||
|
|
}
|
||
|
|
|
||
|
|
internal void Enqueue(SweepEvent evt) {
|
||
|
|
DevTraceInfo(1, "Enqueueing {0}", evt);
|
||
|
|
eventTree.Enqueue(evt);
|
||
|
|
}
|
||
|
|
|
||
|
|
internal SweepEvent Dequeue() {
|
||
|
|
SweepEvent evt = eventTree.Dequeue();
|
||
|
|
DevTraceInfo(1, "Dequeueing {0}", evt);
|
||
|
|
return evt;
|
||
|
|
}
|
||
|
|
|
||
|
|
internal int Count {
|
||
|
|
get { return eventTree.Count; }
|
||
|
|
}
|
||
|
|
|
||
|
|
#region IComparer<SweepEvent>
|
||
|
|
/// <summary>
|
||
|
|
/// For ordering events in the event list.
|
||
|
|
/// Assuming vertical sweep (sweeping up from bottom, scanning horizontally) then order events
|
||
|
|
/// first by lowest Y coord, then by lowest X coord (thus assuming we use Cartesian coordinates
|
||
|
|
/// (negative is downward == bottom).
|
||
|
|
/// </summary>
|
||
|
|
/// <param name="lhs"></param>
|
||
|
|
/// <param name="rhs"></param>
|
||
|
|
/// <returns></returns>
|
||
|
|
public int Compare(SweepEvent lhs, SweepEvent rhs) {
|
||
|
|
if (lhs == rhs) {
|
||
|
|
return 0;
|
||
|
|
}
|
||
|
|
if (lhs == null) {
|
||
|
|
return -1;
|
||
|
|
}
|
||
|
|
if (rhs == null) {
|
||
|
|
return 1;
|
||
|
|
}
|
||
|
|
|
||
|
|
// First see if it's at the same scanline level (perpendicular coordinate).
|
||
|
|
int cmp = scanDirection.ComparePerpCoord(lhs.Site, rhs.Site);
|
||
|
|
if (0 == cmp) {
|
||
|
|
// Event sites are at the same scanline level. Make sure that any reflection events are lowest (come before
|
||
|
|
// any side events, which could remove the side the reflection event was queued for). We may have two
|
||
|
|
// reflection events at same coordinate, because we enqueue in two situations: when a side is opened,
|
||
|
|
// and when a side that is within that side's scanline-parallel span is closed.
|
||
|
|
bool lhsIsNotReflection = !(lhs is BasicReflectionEvent);
|
||
|
|
bool rhsIsNotReflection = !(rhs is BasicReflectionEvent);
|
||
|
|
cmp = lhsIsNotReflection.CompareTo(rhsIsNotReflection);
|
||
|
|
|
||
|
|
// If the scanline-parallel coordinate is the same these events are at the same point.
|
||
|
|
if (0 == cmp) {
|
||
|
|
cmp = scanDirection.CompareScanCoord(lhs.Site, rhs.Site);
|
||
|
|
}
|
||
|
|
}
|
||
|
|
return cmp;
|
||
|
|
}
|
||
|
|
#endregion // IComparer<SweepEvent>
|
||
|
|
|
||
|
|
#region DevTrace
|
||
|
|
#if DEVTRACE
|
||
|
|
readonly DevTrace eventQueueTrace = new DevTrace("Rectilinear_EventQueueTrace", "EventQueue");
|
||
|
|
#endif // DEVTRACE
|
||
|
|
|
||
|
|
[Conditional("DEVTRACE")]
|
||
|
|
[System.Diagnostics.CodeAnalysis.SuppressMessage("Microsoft.Performance", "CA1822:MarkMembersAsStatic")]
|
||
|
|
void DevTraceInfo(int verboseLevel, string format, params object[] args) {
|
||
|
|
#if DEVTRACE
|
||
|
|
eventQueueTrace.WriteLineIf(DevTrace.Level.Info, verboseLevel, format, args);
|
||
|
|
#endif // DEVTRACE
|
||
|
|
}
|
||
|
|
#endregion // DevTrace
|
||
|
|
}
|
||
|
|
}
|