Mercurial > dive4elements > gnv-client

comparison gnv-artifacts/src/main/java/de/intevation/gnv/math/GridCell.java @ 540:80630520e25a

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merged gnv-artifacts/0.4
author Thomas Arendsen Hein <thomas@intevation.de>
date Fri, 28 Sep 2012 12:13:49 +0200
parents 4e347624ee7c
children b248531fa20b
comparison
equal deleted inserted replaced
415:9f4a0b990d27 540:80630520e25a
1 package de.intevation.gnv.math;
2
3 import com.vividsolutions.jts.geom.Coordinate;
4 import com.vividsolutions.jts.geom.Envelope;
5 import com.vividsolutions.jts.geom.Geometry;
6 import com.vividsolutions.jts.geom.GeometryFactory;
7 import com.vividsolutions.jts.geom.LinearRing;
8 import com.vividsolutions.jts.geom.Point;
9 import com.vividsolutions.jts.geom.Polygon;
10
11 import com.vividsolutions.jts.index.ItemVisitor;
12
13 import java.io.Serializable;
14
15 import java.util.ArrayList;
16 import java.util.HashMap;
17 import java.util.List;
18
19 import org.apache.log4j.Logger;
20
21 /**
22 * @author Sascha L. Teichmann (sascha.teichmann@intevation.de)
23 */
24 public class GridCell
25 implements Serializable
26 {
27 private static Logger log = Logger.getLogger(GridCell.class);
28
29 public static final class CellFinder
30 implements ItemVisitor
31 {
32 public GridCell found;
33
34 protected Point point;
35
36 public CellFinder() {
37 }
38
39 public void prepare(Coordinate center) {
40 found = null;
41 point = GEOMETRY_FACTORY.createPoint(center);
42 }
43
44 public void visitItem(Object item) {
45 if (found == null) {
46 GridCell cell = (GridCell)item;
47 if (cell.contains(point)) {
48 found = cell;
49 }
50 }
51 }
52 } // class CellFinder
53
54 public Point2d p1;
55 public Point2d p2;
56 public Point2d p3;
57 public Point2d p4;
58
59 protected Polygon polygon;
60
61 public static final GeometryFactory GEOMETRY_FACTORY
62 = new GeometryFactory();
63
64 public GridCell() {
65 }
66
67 public GridCell(Point2d p1, Point2d p2, Point2d p3, Point2d p4) {
68 this.p1 = p1;
69 this.p2 = p2;
70 this.p3 = p3;
71 this.p4 = p4;
72 createPolygon();
73 }
74
75 protected void createPolygon() {
76 LinearRing shell = GEOMETRY_FACTORY
77 .createLinearRing(new Coordinate [] { p1, p2, p3, p4, p1 });
78 polygon = GEOMETRY_FACTORY.createPolygon(shell, null);
79 }
80
81 public Envelope getEnvelope() {
82 return polygon.getEnvelopeInternal();
83 }
84
85 public boolean contains(Geometry coord) {
86 return polygon.contains(coord);
87 }
88
89 public static List<GridCell> pointsToGridCells(
90 List<? extends Point2d> points
91 ) {
92 return pointsToGridCells(points, null);
93 }
94
95 public static List<GridCell> pointsToGridCells(
96 List<? extends Point2d> points,
97 Envelope relevantArea
98 ) {
99 int minI = Integer.MAX_VALUE;
100 int maxI = Integer.MIN_VALUE;
101 int minJ = Integer.MAX_VALUE;
102 int maxJ = Integer.MIN_VALUE;
103
104 HashMap<Integer, HashMap<Integer, Point2d>> rows =
105 new HashMap<Integer, HashMap<Integer, Point2d>>();
106
107 int culled = 0;
108
109 for (Point2d p: points) {
110
111 if (relevantArea != null && !relevantArea.contains(p.x, p.y)) {
112 ++culled;
113 continue;
114 }
115
116 if (p.i < minI) minI = p.i;
117 if (p.i > maxI) maxI = p.i;
118 if (p.j < minJ) minJ = p.j;
119 if (p.j > maxJ) maxJ = p.j;
120
121 HashMap<Integer, Point2d> row = rows.get(p.i);
122
123 if (row == null) {
124 rows.put(p.i, row = new HashMap<Integer, Point2d>());
125 }
126
127 row.put(p.j, p);
128 }
129
130 ArrayList<GridCell> cells = new ArrayList<GridCell>(points.size());
131
132 for (int i = minI + 1; i <= maxI; ++i) {
133 HashMap<Integer, Point2d> row1 = rows.get(i-1);
134 HashMap<Integer, Point2d> row2 = rows.get(i);
135 if (row1 != null && row2 != null) {
136 for (int j = minJ + 1; j < maxJ; ++j) {
137 Point2d p1 = row1.get(j-1);
138 Point2d p2 = row1.get(j);
139 Point2d p3 = row2.get(j);
140 Point2d p4 = row2.get(j-1);
141
142 if (p1 != null && p2 != null && p3 != null && p4 != null) {
143 cells.add(new GridCell(p1, p2, p3, p4));
144 }
145 } // for all columns in row
146 }
147 } // for all rows
148
149 if (log.isDebugEnabled()) {
150 log.debug("culled points: " + culled);
151 log.debug("min/max i: " + minI + " / " + maxI);
152 log.debug("min/max j: " + minJ + " / " + maxJ);
153 log.debug("cells found: " + cells.size());
154 }
155
156 return cells;
157 }
158 }
159 // vim:set ts=4 sw=4 si et sta sts=4 fenc=utf8 :
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