001// License: GPL. For details, see LICENSE file.
002package org.openstreetmap.josm.data.validation.util;
003
004import java.awt.geom.Point2D;
005import java.util.ArrayList;
006import java.util.Collections;
007import java.util.HashSet;
008import java.util.List;
009import java.util.Map;
010import java.util.Set;
011
012import org.openstreetmap.josm.data.coor.EastNorth;
013import org.openstreetmap.josm.data.osm.Node;
014import org.openstreetmap.josm.data.osm.Way;
015import org.openstreetmap.josm.data.validation.OsmValidator;
016import org.openstreetmap.josm.tools.CheckParameterUtil;
017
018/**
019 * Utility class
020 *
021 * @author frsantos
022 */
023public final class ValUtil {
024
025    private ValUtil() {
026        // Hide default constructor for utils classes
027    }
028
029    /**
030     * Returns the start and end cells of a way.
031     * @param w The way
032     * @param cellWays The map with all cells
033     * @return A list with all the cells the way starts or ends
034     */
035    public static List<List<Way>> getWaysInCell(Way w, Map<Point2D, List<Way>> cellWays) {
036        if (w.getNodesCount() == 0)
037            return Collections.emptyList();
038
039        Node n1 = w.getNode(0);
040        Node n2 = w.getNode(w.getNodesCount() - 1);
041
042        List<List<Way>> cells = new ArrayList<>(2);
043        Set<Point2D> cellNodes = new HashSet<>();
044        Point2D cell;
045
046        // First, round coordinates
047        // CHECKSTYLE.OFF: SingleSpaceSeparator
048        long x0 = Math.round(n1.getEastNorth().east()  * OsmValidator.griddetail);
049        long y0 = Math.round(n1.getEastNorth().north() * OsmValidator.griddetail);
050        long x1 = Math.round(n2.getEastNorth().east()  * OsmValidator.griddetail);
051        long y1 = Math.round(n2.getEastNorth().north() * OsmValidator.griddetail);
052        // CHECKSTYLE.ON: SingleSpaceSeparator
053
054        // Start of the way
055        cell = new Point2D.Double(x0, y0);
056        cellNodes.add(cell);
057        List<Way> ways = cellWays.get(cell);
058        if (ways == null) {
059            ways = new ArrayList<>();
060            cellWays.put(cell, ways);
061        }
062        cells.add(ways);
063
064        // End of the way
065        cell = new Point2D.Double(x1, y1);
066        if (!cellNodes.contains(cell)) {
067            cellNodes.add(cell);
068            ways = cellWays.get(cell);
069            if (ways == null) {
070                ways = new ArrayList<>();
071                cellWays.put(cell, ways);
072            }
073            cells.add(ways);
074        }
075
076        // Then floor coordinates, in case the way is in the border of the cell.
077        // CHECKSTYLE.OFF: SingleSpaceSeparator
078        x0 = (long) Math.floor(n1.getEastNorth().east()  * OsmValidator.griddetail);
079        y0 = (long) Math.floor(n1.getEastNorth().north() * OsmValidator.griddetail);
080        x1 = (long) Math.floor(n2.getEastNorth().east()  * OsmValidator.griddetail);
081        y1 = (long) Math.floor(n2.getEastNorth().north() * OsmValidator.griddetail);
082        // CHECKSTYLE.ON: SingleSpaceSeparator
083
084        // Start of the way
085        cell = new Point2D.Double(x0, y0);
086        if (!cellNodes.contains(cell)) {
087            cellNodes.add(cell);
088            ways = cellWays.get(cell);
089            if (ways == null) {
090                ways = new ArrayList<>();
091                cellWays.put(cell, ways);
092            }
093            cells.add(ways);
094        }
095
096        // End of the way
097        cell = new Point2D.Double(x1, y1);
098        if (!cellNodes.contains(cell)) {
099            cellNodes.add(cell);
100            ways = cellWays.get(cell);
101            if (ways == null) {
102                ways = new ArrayList<>();
103                cellWays.put(cell, ways);
104            }
105            cells.add(ways);
106        }
107        return cells;
108    }
109
110    /**
111     * Returns the coordinates of all cells in a grid that a line between 2 nodes intersects with.
112     *
113     * @param n1 The first node.
114     * @param n2 The second node.
115     * @param gridDetail The detail of the grid. Bigger values give smaller
116     * cells, but a bigger number of them.
117     * @return A list with the coordinates of all cells
118     * @throws IllegalArgumentException if n1 or n2 is {@code null} or without coordinates
119     */
120    public static List<Point2D> getSegmentCells(Node n1, Node n2, double gridDetail) {
121        CheckParameterUtil.ensureParameterNotNull(n1, "n1");
122        CheckParameterUtil.ensureParameterNotNull(n1, "n2");
123        return getSegmentCells(n1.getEastNorth(), n2.getEastNorth(), gridDetail);
124    }
125
126    /**
127     * Returns the coordinates of all cells in a grid that a line between 2 nodes intersects with.
128     *
129     * @param en1 The first EastNorth.
130     * @param en2 The second EastNorth.
131     * @param gridDetail The detail of the grid. Bigger values give smaller
132     * cells, but a bigger number of them.
133     * @return A list with the coordinates of all cells
134     * @throws IllegalArgumentException if en1 or en2 is {@code null}
135     * @since 6869
136     */
137    public static List<Point2D> getSegmentCells(EastNorth en1, EastNorth en2, double gridDetail) {
138        CheckParameterUtil.ensureParameterNotNull(en1, "en1");
139        CheckParameterUtil.ensureParameterNotNull(en2, "en2");
140        List<Point2D> cells = new ArrayList<>();
141        double x0 = en1.east() * gridDetail;
142        double x1 = en2.east() * gridDetail;
143        double y0 = en1.north() * gridDetail + 1;
144        double y1 = en2.north() * gridDetail + 1;
145
146        if (x0 > x1) {
147            // Move to 1st-4th cuadrants
148            double aux;
149            aux = x0; x0 = x1; x1 = aux;
150            aux = y0; y0 = y1; y1 = aux;
151        }
152
153        double dx = x1 - x0;
154        double dy = y1 - y0;
155        long stepY = y0 <= y1 ? 1 : -1;
156        long gridX0 = (long) Math.floor(x0);
157        long gridX1 = (long) Math.floor(x1);
158        long gridY0 = (long) Math.floor(y0);
159        long gridY1 = (long) Math.floor(y1);
160
161        long maxSteps = (gridX1 - gridX0) + Math.abs(gridY1 - gridY0) + 1;
162        while ((gridX0 <= gridX1 && (gridY0 - gridY1)*stepY <= 0) && maxSteps-- > 0) {
163            cells.add(new Point2D.Double(gridX0, gridY0));
164
165            // Is the cross between the segment and next vertical line nearer than the cross with next horizontal line?
166            // Note: segment line formula: y=dy/dx(x-x1)+y1
167            // Note: if dy < 0, must use *bottom* line. If dy > 0, must use upper line
168            double scanY = dy/dx * (gridX0 + 1 - x1) + y1 + (dy < 0 ? -1 : 0);
169            double scanX = dx/dy * (gridY0 + (dy < 0 ? 0 : 1)*stepY - y1) + x1;
170
171            double distX = Math.pow(gridX0 + 1 - x0, 2) + Math.pow(scanY - y0, 2);
172            double distY = Math.pow(scanX - x0, 2) + Math.pow(gridY0 + stepY - y0, 2);
173
174            if (distX < distY) {
175                gridX0 += 1;
176            } else {
177                gridY0 += stepY;
178            }
179        }
180        return cells;
181    }
182}