85 lines
2.2 KiB
C#
85 lines
2.2 KiB
C#
using UnityEngine;
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using System;
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using System.Collections;
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using System.Collections.Generic;
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namespace TGS.Geom {
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class EventQueue {
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List<SweepEvent>elements;
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bool sorted;
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int pointer;
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public EventQueue () {
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elements = new List<SweepEvent> (1000);
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sorted = false;
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pointer = -1;
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}
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public void Enqueue (SweepEvent obj) {
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if (!sorted) {
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elements.Add (obj);
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pointer = elements.Count-1;
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return;
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}
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// If already sorted use insertionSort on the inserted item.
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// int count = pointer = elements.Count;
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if (pointer < 0) {
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elements.Add (obj);
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pointer = 0;
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return;
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}
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elements.Add (null); // Expand the Vector by one.
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int i = pointer;
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pointer++;
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while (i >= 0 && CompareSweepEvent(obj, elements[i]) == -1) {
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elements [i + 1] = elements [i];
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i--;
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}
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elements [i + 1] = obj;
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}
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// The ordering is reversed because push and pop are faster.
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int CompareSweepEvent (SweepEvent e1, SweepEvent e2) {
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if (e1.Equals(e2)) return 0;
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if (e1.p.x - e2.p.x > Point.PRECISION) // Different x coordinate
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return -1;
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if (e1.p.x - e2.p.x < -Point.PRECISION) // Different x coordinate
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return 1;
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if ( e1.p.y - e2.p.y > Point.PRECISION) // Different points, but same x coordinate. The event with lower y coordinate is processed first
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return -1;
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if ( e1.p.y - e2.p.y < -Point.PRECISION ) // Different points, but same x coordinate. The event with lower y coordinate is processed first
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return 1;
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if (e1.isLeft != e2.isLeft) // Same point, but one is a left endpoint and the other a right endpoint. The right endpoint is processed first
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return (e1.isLeft) ? -1 : 1;
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// Same point, both events are left endpoints or both are right endpoints. The event associate to the bottom segment is processed first
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bool isAbove = e1.isAbove (e2.otherSE.p);
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return isAbove ? -1 : 1;
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}
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public SweepEvent Dequeue () {
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if (!sorted) {
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elements.Sort (CompareSweepEvent);
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sorted = true;
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}
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// SweepEvent e = elements [elements.Count - 1];
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// elements.RemoveAt (elements.Count - 1);
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// return e;
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return elements [pointer--];
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}
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public bool isEmpty { get {
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// return elements.Count == 0;
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return pointer<0;
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} }
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}
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} |