[7193] | 1 | // License: GPL. For details, see LICENSE file.
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| 2 | package org.openstreetmap.josm.tools;
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| 3 |
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| 4 | import org.openstreetmap.josm.data.coor.LatLon;
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| 5 | import org.openstreetmap.josm.data.osm.BBox;
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| 6 |
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| 7 | /**
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| 8 | * Fast index to look up properties of the earth surface.
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[7509] | 9 | *
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[7193] | 10 | * It is expected that there is a relatively slow method to look up the property
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| 11 | * for a certain coordinate and that there are larger areas with a uniform
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| 12 | * property.
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[7509] | 13 | *
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[7193] | 14 | * This index tries to find rectangles with uniform property and caches them.
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| 15 | * Rectangles are subdivided, if there are different properties within.
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| 16 | * (Up to a maximum level, when the slow method is used again.)
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[7509] | 17 | *
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[7193] | 18 | * @param <T> the property (like land/water or nation)
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| 19 | */
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| 20 | public class GeoPropertyIndex<T> {
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[7509] | 21 |
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[7193] | 22 | private final int maxLevel;
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| 23 | private final GeoProperty<T> geoProp;
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| 24 | private final GPLevel<T> root;
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| 25 | private GPLevel<T> lastLevelUsed;
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[7509] | 26 |
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[7193] | 27 | private static final boolean DEBUG = false;
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| 28 |
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| 29 | /**
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| 30 | * Create new GeoPropertyIndex.
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| 31 | * @param geoProp the input property that should be made faster by this index
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[8470] | 32 | * @param maxLevel max level
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[7193] | 33 | */
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| 34 | public GeoPropertyIndex(GeoProperty<T> geoProp, int maxLevel) {
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| 35 | this.geoProp = geoProp;
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| 36 | this.maxLevel = maxLevel;
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[9070] | 37 | this.root = new GPLevel<>(0, new BBox(-180, -90, 180, 90), null, this);
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[7193] | 38 | this.lastLevelUsed = root;
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| 39 | }
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[7509] | 40 |
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[7193] | 41 | /**
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| 42 | * Look up the property for a certain point.
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[7592] | 43 | * This gives the same result as {@link GeoProperty#get(LatLon)}, but
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[7193] | 44 | * should be faster.
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| 45 | * @param ll the point coordinates
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| 46 | * @return property value at that point
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| 47 | */
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| 48 | public T get(LatLon ll) {
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| 49 | return lastLevelUsed.get(ll);
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| 50 | }
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[7509] | 51 |
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[12382] | 52 | /**
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| 53 | * Gets the index of the given coordinate. Only used internally
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| 54 | * @param ll The lat/lon coordinate
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| 55 | * @param level The scale level
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| 56 | * @return The index for that position
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| 57 | */
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[7193] | 58 | public static int index(LatLon ll, int level) {
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[10316] | 59 | long noParts = 1L << level;
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[8510] | 60 | long x = ((long) ((ll.lon() + 180.0) * noParts / 360.0)) & 1;
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| 61 | long y = ((long) ((ll.lat() + 90.0) * noParts / 180.0)) & 1;
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[7193] | 62 | return (int) (2 * x + y);
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| 63 | }
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| 64 |
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| 65 | protected static class GPLevel<T> {
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| 66 | private final T val;
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| 67 | private final int level;
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| 68 | private final BBox bbox;
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| 69 | private final GPLevel<T> parent;
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| 70 | private final GeoPropertyIndex<T> owner;
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| 71 |
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| 72 | // child order by index is sw, nw, se, ne
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| 73 | private GPLevel<T>[] children;
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| 74 |
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| 75 | public GPLevel(int level, BBox bbox, GPLevel<T> parent, GeoPropertyIndex<T> owner) {
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| 76 | this.level = level;
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| 77 | this.bbox = bbox;
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| 78 | this.parent = parent;
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| 79 | this.owner = owner;
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| 80 | this.val = owner.geoProp.get(bbox);
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| 81 | }
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| 82 |
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| 83 | public T get(LatLon ll) {
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[7353] | 84 | if (isInside(ll))
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[7193] | 85 | return getBounded(ll);
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| 86 | if (DEBUG) System.err.print("up["+level+"]");
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| 87 | return parent.get(ll);
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| 88 | }
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[7509] | 89 |
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[7193] | 90 | private T getBounded(LatLon ll) {
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| 91 | if (DEBUG) System.err.print("GPLevel["+level+"]"+bbox+" ");
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[7353] | 92 | if (!isInside(ll)) {
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[7193] | 93 | throw new AssertionError("Point "+ll+" should be inside "+bbox);
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| 94 | }
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| 95 | if (val != null) {
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| 96 | if (DEBUG) System.err.println(" hit! "+val);
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| 97 | owner.lastLevelUsed = this;
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| 98 | return val;
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| 99 | }
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| 100 | if (level >= owner.maxLevel) {
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| 101 | if (DEBUG) System.err.println(" max level reached !");
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| 102 | return owner.geoProp.get(ll);
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| 103 | }
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[7509] | 104 |
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[7193] | 105 | if (children == null) {
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| 106 | @SuppressWarnings("unchecked")
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[7596] | 107 | GPLevel<T>[] tmp = new GPLevel[4];
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[7193] | 108 | this.children = tmp;
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| 109 | }
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[7509] | 110 |
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[7193] | 111 | int idx = index(ll, level+1);
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| 112 | if (children[idx] == null) {
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| 113 | double lon1, lat1;
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| 114 | switch (idx) {
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[7509] | 115 | case 0:
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[7193] | 116 | lon1 = bbox.getTopLeftLon();
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| 117 | lat1 = bbox.getBottomRightLat();
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| 118 | break;
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| 119 | case 1:
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| 120 | lon1 = bbox.getTopLeftLon();
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| 121 | lat1 = bbox.getTopLeftLat();
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| 122 | break;
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[7509] | 123 | case 2:
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[7193] | 124 | lon1 = bbox.getBottomRightLon();
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| 125 | lat1 = bbox.getBottomRightLat();
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| 126 | break;
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[7509] | 127 | case 3:
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[7193] | 128 | lon1 = bbox.getBottomRightLon();
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| 129 | lat1 = bbox.getTopLeftLat();
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| 130 | break;
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| 131 | default:
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| 132 | throw new AssertionError();
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| 133 | }
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| 134 | if (DEBUG) System.err.println(" - new with idx "+idx);
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| 135 | LatLon center = bbox.getCenter();
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[8510] | 136 | BBox b = new BBox(lon1, lat1, center.lon(), center.lat());
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[7193] | 137 | children[idx] = new GPLevel<>(level + 1, b, this, owner);
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| 138 | }
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| 139 | return children[idx].getBounded(ll);
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| 140 | }
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[7509] | 141 |
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[7353] | 142 | /**
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| 143 | * Checks, if a point is inside this tile.
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| 144 | * Makes sure, that neighboring tiles do not overlap, i.e. a point exactly
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| 145 | * on the border of two tiles must be inside exactly one of the tiles.
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| 146 | * @param ll the coordinates of the point
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| 147 | * @return true, if it is inside of the box
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| 148 | */
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| 149 | boolean isInside(LatLon ll) {
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[7509] | 150 | return bbox.getTopLeftLon() <= ll.lon() &&
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[8416] | 151 | (ll.lon() < bbox.getBottomRightLon() || (ll.lon() == 180.0 && bbox.getBottomRightLon() == 180.0)) &&
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[7509] | 152 | bbox.getBottomRightLat() <= ll.lat() &&
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[8416] | 153 | (ll.lat() < bbox.getTopLeftLat() || (ll.lat() == 90.0 && bbox.getTopLeftLat() == 90.0));
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[7353] | 154 | }
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[7193] | 155 |
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[11259] | 156 | @Override
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| 157 | public String toString() {
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| 158 | return "GPLevel [val=" + val + ", level=" + level + ", bbox=" + bbox + ']';
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| 159 | }
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[7193] | 160 | }
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[11259] | 161 |
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| 162 | @Override
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| 163 | public String toString() {
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| 164 | return "GeoPropertyIndex [maxLevel=" + maxLevel + ", geoProp=" + geoProp + ", root=" + root + ", lastLevelUsed="
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| 165 | + lastLevelUsed + ']';
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| 166 | }
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[7193] | 167 | }
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