diff options
| -rw-r--r-- | main/src/cgeo/geocaching/connector/gc/Tile.java | 97 | ||||
| -rw-r--r-- | tests/src/cgeo/geocaching/connector/gc/AutoZoomTest.java | 49 |
2 files changed, 119 insertions, 27 deletions
diff --git a/main/src/cgeo/geocaching/connector/gc/Tile.java b/main/src/cgeo/geocaching/connector/gc/Tile.java index 73ded4d..083179e 100644 --- a/main/src/cgeo/geocaching/connector/gc/Tile.java +++ b/main/src/cgeo/geocaching/connector/gc/Tile.java @@ -53,11 +53,15 @@ public class Tile { private final Viewport viewPort; public Tile(Geopoint origin, int zoomlevel) { + this(calcX(origin, clippedZoomlevel(zoomlevel)), calcY(origin, clippedZoomlevel(zoomlevel)), clippedZoomlevel(zoomlevel)); + } + + private Tile(int tileX, int tileY, int zoomlevel) { - this.zoomlevel = Math.max(Math.min(zoomlevel, ZOOMLEVEL_MAX), ZOOMLEVEL_MIN); + this.zoomlevel = clippedZoomlevel(zoomlevel); - tileX = calcX(origin); - tileY = calcY(origin); + this.tileX = tileX; + this.tileY = tileY; viewPort = new Viewport(getCoord(new UTFGridPosition(0, 0)), getCoord(new UTFGridPosition(63, 63))); } @@ -66,28 +70,32 @@ public class Tile { return zoomlevel; } + private static int clippedZoomlevel(int zoomlevel) { + return Math.max(Math.min(zoomlevel, ZOOMLEVEL_MAX), ZOOMLEVEL_MIN); + } + /** * Calculate the tile for a Geopoint based on the Spherical Mercator. * * @see <a * href="http://developers.cloudmade.com/projects/tiles/examples/convert-coordinates-to-tile-numbers">Cloudmade</a> */ - private int calcX(final Geopoint origin) { - return (int) ((origin.getLongitude() + 180.0) / 360.0 * NUMBER_OF_TILES[this.zoomlevel]); + private static int calcX(final Geopoint origin, final int zoomlevel) { + return (int) ((origin.getLongitude() + 180.0) / 360.0 * NUMBER_OF_TILES[zoomlevel]); } /** * Calculate the tile for a Geopoint based on the Spherical Mercator. * */ - private int calcY(final Geopoint origin) { + private static int calcY(final Geopoint origin, final int zoomlevel) { // double latRad = Math.toRadians(origin.getLatitude()); // return (int) ((1 - (Math.log(Math.tan(latRad) + (1 / Math.cos(latRad))) / Math.PI)) / 2 * numberOfTiles); // Optimization from Bing double sinLatRad = Math.sin(Math.toRadians(origin.getLatitude())); - return (int) ((0.5 - Math.log((1 + sinLatRad) / (1 - sinLatRad)) / (4 * Math.PI)) * NUMBER_OF_TILES[this.zoomlevel]); + return (int) ((0.5 - Math.log((1 + sinLatRad) / (1 - sinLatRad)) / (4 * Math.PI)) * NUMBER_OF_TILES[zoomlevel]); } public int getX() { @@ -121,7 +129,12 @@ public class Tile { /** * Calculates the maximum possible zoom level where the supplied points - * are covered by adjacent tiles on the east/west axis. + * are covered by at least by the supplied number of + * adjacent tiles on the east/west axis. + * This criterion can be exactly met for even numbers of tiles + * while it may result in one more tile as requested for odd numbers + * of tiles. + * * The order of the points (left/right) is irrelevant. * * @param left @@ -130,17 +143,17 @@ public class Tile { * Second point * @return */ - public static int calcZoomLon(final Geopoint left, final Geopoint right) { + public static int calcZoomLon(final Geopoint left, final Geopoint right, final int numberOfTiles) { int zoom = (int) Math.floor( - Math.log(360.0 / Math.abs(left.getLongitude() - right.getLongitude())) + Math.log(360.0 * numberOfTiles / (2.0 * Math.abs(left.getLongitude() - right.getLongitude()))) / Math.log(2) ); Tile tileLeft = new Tile(left, zoom); Tile tileRight = new Tile(right, zoom); - if (tileLeft.tileX == tileRight.tileX) { + if (Math.abs(tileLeft.tileX - tileRight.tileX) < (numberOfTiles - 1)) { zoom += 1; } @@ -149,7 +162,12 @@ public class Tile { /** * Calculates the maximum possible zoom level where the supplied points - * are covered by adjacent tiles on the north/south axis. + * are covered by at least by the supplied number of + * adjacent tiles on the north/south axis. + * This criterion can be exactly met for even numbers of tiles + * while it may result in one more tile as requested for odd numbers + * of tiles. + * * The order of the points (bottom/top) is irrelevant. * * @param bottom @@ -158,21 +176,21 @@ public class Tile { * Second point * @return */ - public static int calcZoomLat(final Geopoint bottom, final Geopoint top) { + public static int calcZoomLat(final Geopoint bottom, final Geopoint top, final int numberOfTiles) { int zoom = (int) Math.ceil( - Math.log(2.0 * Math.PI / + Math.log(2.0 * Math.PI * numberOfTiles / ( Math.abs( asinh(tanGrad(bottom.getLatitude())) - asinh(tanGrad(top.getLatitude())) - ) + ) * 2.0) ) / Math.log(2) ); Tile tileBottom = new Tile(bottom, zoom); Tile tileTop = new Tile(top, zoom); - if (Math.abs(tileBottom.tileY - tileTop.tileY) > 1) { + if (Math.abs(tileBottom.tileY - tileTop.tileY) > (numberOfTiles - 1)) { zoom -= 1; } @@ -185,7 +203,7 @@ public class Tile { /** * Calculates the inverted hyperbolic sine - * (after Bronstein, Semendjajew: Taschenbuch der Mathematik + * (after Bronstein, Semendjajew: Taschenbuch der Mathematik) * * @param x * @return @@ -233,19 +251,48 @@ public class Tile { } /** - * Calculate needed tiles for the given viewport - * + * Calculate needed tiles for the given viewport to cover it with + * max 2x2 tiles + * * @param viewport * @return */ protected static Set<Tile> getTilesForViewport(final Viewport viewport) { + return getTilesForViewport(viewport, 2, Tile.ZOOMLEVEL_MIN); + } + + /** + * Calculate needed tiles for the given viewport. + * You can define the minimum number of tiles on the longer axis + * and/or the minimum zoom level. + * + * @param viewport + * @param tilesOnAxis + * @param minZoom + * @return + */ + protected static Set<Tile> getTilesForViewport(final Viewport viewport, final int tilesOnAxis, final int minZoom) { Set<Tile> tiles = new HashSet<Tile>(); - int zoom = Math.min(Tile.calcZoomLon(viewport.bottomLeft, viewport.topRight), - Tile.calcZoomLat(viewport.bottomLeft, viewport.topRight)); - tiles.add(new Tile(viewport.bottomLeft, zoom)); - tiles.add(new Tile(new Geopoint(viewport.getLatitudeMin(), viewport.getLongitudeMax()), zoom)); - tiles.add(new Tile(new Geopoint(viewport.getLatitudeMax(), viewport.getLongitudeMin()), zoom)); - tiles.add(new Tile(viewport.topRight, zoom)); + int zoom = Math.max( + Math.min(Tile.calcZoomLon(viewport.bottomLeft, viewport.topRight, tilesOnAxis), + Tile.calcZoomLat(viewport.bottomLeft, viewport.topRight, tilesOnAxis)), + minZoom); + + Tile tileBottomLeft = new Tile(viewport.bottomLeft, zoom); + Tile tileTopRight = new Tile(viewport.topRight, zoom); + + int xLow = Math.min(tileBottomLeft.getX(), tileTopRight.getX()); + int xHigh = Math.max(tileBottomLeft.getX(), tileTopRight.getX()); + + int yLow = Math.min(tileBottomLeft.getY(), tileTopRight.getY()); + int yHigh = Math.max(tileBottomLeft.getY(), tileTopRight.getY()); + + for (int xNum = xLow; xNum <= xHigh; xNum++) { + for (int yNum = yLow; yNum <= yHigh; yNum++) { + tiles.add(new Tile(xNum, yNum, zoom)); + } + } + return tiles; } diff --git a/tests/src/cgeo/geocaching/connector/gc/AutoZoomTest.java b/tests/src/cgeo/geocaching/connector/gc/AutoZoomTest.java index 234ff26..fb49949 100644 --- a/tests/src/cgeo/geocaching/connector/gc/AutoZoomTest.java +++ b/tests/src/cgeo/geocaching/connector/gc/AutoZoomTest.java @@ -1,6 +1,9 @@ package cgeo.geocaching.connector.gc; import cgeo.geocaching.geopoint.Geopoint; +import cgeo.geocaching.geopoint.Viewport; + +import java.util.Set; import junit.framework.TestCase; @@ -10,16 +13,58 @@ public class AutoZoomTest extends TestCase { Geopoint bottomLeft = new Geopoint(49.3, 8.3); Geopoint topRight = new Geopoint(49.4, 8.4); - int zoom = Tile.calcZoomLat(bottomLeft, topRight); + int zoom = Tile.calcZoomLat(bottomLeft, topRight, 2); assertTrue(Math.abs(new Tile(bottomLeft, zoom).getY() - new Tile(topRight, zoom).getY()) == 1); assertTrue(Math.abs(new Tile(bottomLeft, zoom + 1).getY() - new Tile(topRight, zoom + 1).getY()) > 1); - zoom = Tile.calcZoomLon(bottomLeft, topRight); + zoom = Tile.calcZoomLon(bottomLeft, topRight, 2); assertTrue(new Tile(bottomLeft, zoom).getX() + 1 == new Tile(topRight, zoom).getX()); assertTrue(new Tile(bottomLeft, zoom + 1).getX() + 1 < new Tile(topRight, zoom + 1).getX()); } + public static void testZoom2() { + Geopoint bottomLeft = new Geopoint(49.3, 8.3); + Geopoint topRight = new Geopoint(49.4, 8.4); + + int zoom = Tile.calcZoomLat(bottomLeft, topRight, 3); + + assertTrue(Math.abs(new Tile(bottomLeft, zoom).getY() - new Tile(topRight, zoom).getY()) >= 2); + assertTrue(Math.abs(new Tile(bottomLeft, zoom + 1).getY() - new Tile(topRight, zoom + 1).getY()) > 2); + + zoom = Tile.calcZoomLon(bottomLeft, topRight, 3); + + assertTrue(Math.abs(new Tile(bottomLeft, zoom).getX() - new Tile(topRight, zoom).getX()) >= 2); + assertTrue(Math.abs(new Tile(bottomLeft, zoom + 1).getX() - new Tile(topRight, zoom + 1).getX()) > 2); + + } + + public static void testTiles1x2() { + Geopoint bottomLeft = new Geopoint(49.3, 8.3); + Geopoint topRight = new Geopoint(49.4, 8.4); + + Set<Tile> tiles = Tile.getTilesForViewport(new Viewport(bottomLeft, topRight)); + + assertEquals(2, tiles.size()); + } + + public static void testTiles2x3() { + Geopoint bottomLeft = new Geopoint(49.3, 8.3); + Geopoint topRight = new Geopoint(49.4, 8.4); + + Set<Tile> tiles = Tile.getTilesForViewport(new Viewport(bottomLeft, topRight), 3, Tile.ZOOMLEVEL_MIN); + + assertEquals(6, tiles.size()); + } + + public static void testTilesZoom13() { + Geopoint bottomLeft = new Geopoint(49.3, 8.3); + Geopoint topRight = new Geopoint(49.4, 8.4); + + Set<Tile> tiles = Tile.getTilesForViewport(new Viewport(bottomLeft, topRight), 3, 13); + + assertEquals(16, tiles.size()); + } } |