Changeset 3787 in josm

Timestamp:

2011-01-13T18:00:36+01:00 (14 years ago)

Author:

Upliner

Message:

Another rework of autozoom algorithm, fixes flicker when zooming in.

Also uses binary search of neccecary zoomlevel when downloading instead of linear one.
Has less code, more comments and more comprehensible at all.

File:

• trunk/src/org/openstreetmap/josm/gui/layer/TMSLayer.java (modified) (4 diffs)

trunk/src/org/openstreetmap/josm/gui/layer/TMSLayer.java

@@ -1021 +1021 @@
     private class DeepTileSet {
         final EastNorth topLeft, botRight;
-        final int minZoom;
+        final int minZoom, maxZoom;
         private final TileSet[] tileSets;
         private final TileSetInfo[] tileSetInfos;
@@ -1028 +1028 @@
             this.botRight = botRight;
             this.minZoom = minZoom;
+            this.maxZoom = maxZoom;
             this.tileSets = new TileSet[maxZoom - minZoom + 1];
             this.tileSetInfos = new TileSetInfo[maxZoom - minZoom + 1];
@@ -1077 +1078 @@
         }
 
-        DeepTileSet dts = new DeepTileSet(topLeft, botRight, getMinZoomLvl(), getMaxZoomLvl());
+        DeepTileSet dts = new DeepTileSet(topLeft, botRight, getMinZoomLvl(), zoom);
         TileSet ts = dts.getTileSet(zoom);
 
@@ -1089 +1090 @@
                 noTilesAtZoom = true;
             }
-            if (!tsi.hasVisibleTiles && tsi.hasOverzoomedTiles) {
-                while (displayZoomLevel > dts.minZoom && !tsi.hasVisibleTiles && tsi.hasOverzoomedTiles){
-                    displayZoomLevel--;
-                    tsi = dts.getTileSetInfo(displayZoomLevel);
-                }
-                if (zoom > displayZoomLevel && !dts.getTileSetInfo(displayZoomLevel+1).hasLoadingTiles) {
-                    zoom = displayZoomLevel+1;
-                } else {
-                    zoom = displayZoomLevel;
-                }
-                while (displayZoomLevel >= dts.minZoom && !tsi.hasVisibleTiles){
-                    displayZoomLevel--;
-                    tsi = dts.getTileSetInfo(displayZoomLevel);
-                }
-                if (displayZoomLevel < dts.minZoom) {
-                    displayZoomLevel = 0;
-                }
+            // Find highest zoom level with at least one visible tile
+            while (displayZoomLevel > dts.minZoom &&
+                    !dts.getTileSetInfo(displayZoomLevel).hasVisibleTiles) {
+                displayZoomLevel--;
+            }
+            // Do binary search between currentZoomLevel and displayZoomLevel
+            while (zoom > displayZoomLevel && !tsi.hasVisibleTiles && tsi.hasOverzoomedTiles){
+                zoom = (zoom + displayZoomLevel)/2;
                 tsi = dts.getTileSetInfo(zoom);
             }
+
             setZoomLevel(zoom);
+
+            // If all tiles at displayZoomLevel is loaded, load all tiles at next zoom level
+            // to make sure there're really no more zoom levels
+            if (zoom == displayZoomLevel && !tsi.hasLoadingTiles && zoom < dts.maxZoom) {
+                zoom++;
+                tsi = dts.getTileSetInfo(zoom);
+            }
             // When we have overzoomed tiles and all tiles at current zoomlevel is loaded,
             // load tiles at previovus zoomlevels until we have all tiles on screen is loaded.