Merge pull request #126 from mahomaps/tiles-fallback

Fallback missing tiles to lower zooms

Author: Feodor0090

src/mahomaps/Settings.java

@@ -28,6 +28,10 @@ private Settings() {
 	public static boolean bbWifi;
 	public static boolean firstLaunch = true;
 	public static int map;
+	/**
+	 * Reads "fallback" tile (scaled up) before downloading it.
+	 */
+	public static boolean readCachedBeforeDownloading = false;
 
 	public static String proxyServer = "http://nnp.nnchan.ru:80/mahoproxy.php?u=";
 
@@ -94,6 +98,7 @@ public static synchronized boolean Read() {
 			firstLaunch = j.getBoolean("1", true);
 			usageFlags = j.getInt("tm", 0);
 			map = j.getInt("map", 0);
+			readCachedBeforeDownloading = j.getBoolean("upscale", false);
 			return true;
 		} catch (Throwable e) {
 			e.printStackTrace();
@@ -137,6 +142,7 @@ public static String Serialize() {
 		j.put("1", firstLaunch);
 		j.put("tm", usageFlags);
 		j.put("map", map);
+		j.put("upscale", readCachedBeforeDownloading);
 		return j.toString();
 	}
 

src/mahomaps/map/TileCache.java

@@ -29,15 +29,26 @@ public void paint(Graphics g, int tx, int ty) {
 		Font f = Font.getFont(0, 0, 8);
 		int vo = f.getHeight();
 		g.setFont(f);
+		Image i = img;
+		if (i != null) {
+			g.drawImage(i, tx, ty, 0);
+		}
 		if (state == STATE_READY) {
-			Image i = img;
 			if (i == null) // wtf!?
 				throw new NullPointerException("Corrupted tile state!");
-			g.drawImage(i, tx, ty, 0);
 			g.setColor(0, 0, 255);
 		} else {
+			int ax = tx + 128;
+			int ay = ty + 128 - (vo / 2);
+
+			g.setGrayScale(255);
+			g.drawString(GetState(), ax + 1, ay + 1, Graphics.TOP | Graphics.HCENTER);
+			g.drawString(GetState(), ax - 1, ay + 1, Graphics.TOP | Graphics.HCENTER);
+			g.drawString(GetState(), ax + 1, ay - 1, Graphics.TOP | Graphics.HCENTER);
+			g.drawString(GetState(), ax - 1, ay - 1, Graphics.TOP | Graphics.HCENTER);
+
 			g.setGrayScale(0);
-			g.drawString(GetState(), tx + 128, ty + 128 - vo, Graphics.TOP | Graphics.HCENTER);
+			g.drawString(GetState(), ax, ay, Graphics.TOP | Graphics.HCENTER);
 		}
 		if (Settings.drawDebugInfo) {
 			g.drawRect(tx, ty, 255, 255);

src/mahomaps/map/TilesProvider.java

@@ -23,6 +23,7 @@
 import mahomaps.api.YmapsApiBase;
 import mahomaps.overlays.TileCacheForbiddenOverlay;
 import mahomaps.overlays.TileDownloadForbiddenOverlay;
+import tube42.lib.imagelib.ImageUtils;
 import mahomaps.overlays.CacheFailedOverlay;
 
 public class TilesProvider implements Runnable {
@@ -77,6 +78,10 @@ public static final String[] GetLayerNames() {
 		return s;
 	}
 
+	public String GetLocalPath() {
+		return localPath;
+	}
+
 	public TilesProvider(String lang) {
 		if (lang == null)
 			throw new NullPointerException("Language must be non-null!");
@@ -184,18 +189,40 @@ public void RunCache() {
 						}
 					}
 
-					Image img = null;
-					if (Settings.cacheMode == Settings.CACHE_FS && localPath != null) {
-						img = tryLoadFromFS(tc);
-					} else if (Settings.cacheMode == Settings.CACHE_RMS) {
-						img = tryLoadFromRMS(tc);
+					Image img = tryLoad(tc);
+					boolean tryDownloadAnyway = false;
+
+					// if tile is not cached...
+					if (img == null) {
+						// and cache lookup actually was attempted...
+						if (Settings.cacheMode != Settings.CACHE_DISABLED) {
+							// but we can't download it
+							if (!Settings.allowDownload) {
+								// let's try lower zooms and upscale them.
+								img = tryLoadFallback(tc);
+							}
+							// or scaling explicitly allowed before downloading
+							else if (Settings.readCachedBeforeDownloading) {
+								// let's try lower zooms and upscale them.
+								img = tryLoadFallback(tc);
+								// but still attempt to download
+								tryDownloadAnyway = true;
+							}
+						}
 					}
 
 					synchronized (tc) {
 						if (img != null) {
 							tc.img = img;
-							tc.state = TileCache.STATE_READY;
-							MahoMapsApp.GetCanvas().requestRepaint();
+
+							// readCachedBeforeDownloading is still require server lookup
+							if (tryDownloadAnyway) {
+								tc.state = TileCache.STATE_SERVER_PENDING;
+								downloadGate.Reset();
+							} else {
+								tc.state = TileCache.STATE_READY;
+								MahoMapsApp.GetCanvas().requestRepaint();
+							}
 						} else if (Settings.allowDownload) {
 							tc.state = TileCache.STATE_SERVER_PENDING;
 							downloadGate.Reset();
@@ -211,6 +238,50 @@ public void RunCache() {
 		}
 	}
 
+	private final Image tryLoad(TileId id) {
+		if (Settings.cacheMode == Settings.CACHE_FS && localPath != null) {
+			return tryLoadFromFS(id);
+		} else if (Settings.cacheMode == Settings.CACHE_RMS) {
+			return tryLoadFromRMS(id);
+		}
+		return null;
+	}
+
+	private final Image tryLoadFallback(TileId id) {
+		final int map = id.map;
+		int zoom = id.zoom;
+		int downscale = 1; // how small is required tile comparing to loaded one
+		int x = id.x;
+		int y = id.y;
+		int xoff = 0; // in tile sizes
+		int yoff = 0;
+		while (true) {
+			zoom -= 1;
+			if (zoom < 0 || downscale >= 64)
+				return null;
+			if (x % 2 == 1)
+				xoff += downscale;
+			if (y % 2 == 1)
+				yoff += downscale;
+			// at downscale of 2 above ops require 1, at 4 - 2 and so on
+			downscale *= 2;
+			x /= 2;
+			y /= 2;
+			Image raw = tryLoad(new TileId(x, y, zoom, map));
+			if (raw != null) {
+				int size = (256 / downscale); // of tile
+				// System.out.println("downscale: " + downscale + ", size: " + size);
+				// System.out.println("x: " + xoff + ", y: " + yoff);
+				int xoffp = xoff * size; // in pixels
+				int yoffp = yoff * size;
+				Image cropped = ImageUtils.crop(raw, xoffp, yoffp, xoffp + size, yoffp + size);
+				raw = null; // to free heap
+				return ImageUtils.resize(cropped, 256, 256, true, false);
+			}
+		}
+
+	}
+
 	public void RunNetwork() {
 		try {
 			// цикл обработки
@@ -284,6 +355,20 @@ else if (l != s)
 					}
 
 					Image img = Settings.allowDownload ? download(tc) : null;
+					boolean fallbackUsed = false;
+
+					// if nothing loaded
+					if (img == null) {
+						// if the cache available...
+						if (Settings.cacheMode != Settings.CACHE_DISABLED) {
+							// let's try lower zooms and upscale them.
+							// If download is forbidden, this happened in cache thread and this path won't
+							// run at all.
+							img = tryLoadFallback(tc);
+							if (img != null)
+								fallbackUsed = true;
+						}
+					}
 
 					boolean waitAfterError = false;
 
@@ -297,7 +382,13 @@ else if (l != s)
 							}
 						} else {
 							tc.img = img;
-							tc.state = TileCache.STATE_READY;
+							if (fallbackUsed) {
+								// image is present, but it's bad. We still want to download a proper one.
+								tc.state = TileCache.STATE_ERROR;
+								waitAfterError = true;
+							} else {
+								tc.state = TileCache.STATE_READY;
+							}
 							MahoMapsApp.GetCanvas().requestRepaint();
 						}
 					}
@@ -306,8 +397,10 @@ else if (l != s)
 						Thread.sleep(4000);
 				}
 
-				if (idleCount != cache.size() || queueChanged)
+				if (idleCount != cache.size() || queueChanged) {
+					Thread.yield();
 					continue;
+				}
 				downloadGate.Pass();
 			}
 		} catch (InterruptedException e) {
@@ -389,7 +482,6 @@ private Image download(TileId id) throws InterruptedException {
 			} catch (RuntimeException e1) {
 			}
 		} catch (Exception e) {
-			e.printStackTrace();
 		} catch (OutOfMemoryError e) {
 		} finally {
 			if (hc != null) {
@@ -586,8 +678,7 @@ public TileCache getTile(TileId tileId) {
 	}
 
 	private String getUrl(TileId tileId) {
-		String url = tilesUrls[tileId.map] + lang + "&x=" + tileId.x + "&y=" + tileId.y
-				+ "&z=" + tileId.zoom;
+		String url = tilesUrls[tileId.map] + lang + "&x=" + tileId.x + "&y=" + tileId.y + "&z=" + tileId.zoom;
 		if (Settings.proxyTiles && url.startsWith("https")) {
 			return Settings.proxyServer + YmapsApiBase.EncodeUrl(url);
 		}

src/mahomaps/screens/CacheManager.java

@@ -26,6 +26,8 @@ public CacheManager(TilesProvider tiles) {
 		setCommandListener(this);
 		append(new StringItem(MahoMapsApp.text[71], getCacheType()));
 		append(new StringItem(MahoMapsApp.text[72], "" + tiles.GetCachedTilesCount()));
+		if (Settings.cacheMode == Settings.CACHE_FS)
+			append(new StringItem(MahoMapsApp.text[71], tiles.GetLocalPath()));
 		delAll.setLayout(Item.LAYOUT_NEWLINE_AFTER | Item.LAYOUT_NEWLINE_BEFORE);
 		delAll.setDefaultCommand(sel);
 		delAll.setItemCommandListener(this);

src/mahomaps/screens/SettingsScreen.java

@@ -27,7 +27,7 @@ public class SettingsScreen extends Form implements CommandListener {
 	private ChoiceGroup cache = new ChoiceGroup(MahoMapsApp.text[52], Choice.POPUP,
 			new String[] { MahoMapsApp.text[18], MahoMapsApp.text[53], "RMS" }, null);
 	private ChoiceGroup download = new ChoiceGroup(MahoMapsApp.text[54], Choice.MULTIPLE,
-			new String[] { MahoMapsApp.text[17] }, null);
+			new String[] { MahoMapsApp.text[17], "Upscale existing cache before downloading" }, null);
 	private ChoiceGroup proxyUsage = new ChoiceGroup(MahoMapsApp.text[19], Choice.MULTIPLE,
 			new String[] { MahoMapsApp.text[156], MahoMapsApp.text[157], }, null);
 	private TextField proxyServer = new TextField(MahoMapsApp.text[158], "", 256, TextField.URL);
@@ -72,6 +72,7 @@ public SettingsScreen() {
 		tileInfo.setSelectedIndex(Settings.drawDebugInfo ? 1 : 0, true);
 		cache.setSelectedIndex(Settings.cacheMode, true);
 		download.setSelectedIndex(0, Settings.allowDownload);
+		download.setSelectedIndex(1, Settings.readCachedBeforeDownloading);
 		proxyUsage.setSelectedIndex(0, Settings.proxyTiles);
 		proxyUsage.setSelectedIndex(1, Settings.proxyApi);
 		uiSize.setSelectedIndex(Settings.uiSize, true);
@@ -103,6 +104,7 @@ private void Apply() {
 		Settings.drawDebugInfo = tileInfo.getSelectedIndex() == 1;
 		Settings.cacheMode = cache.getSelectedIndex();
 		Settings.allowDownload = download.isSelected(0);
+		Settings.readCachedBeforeDownloading = download.isSelected(1);
 		Settings.proxyTiles = proxyUsage.isSelected(0);
 		Settings.proxyApi = proxyUsage.isSelected(1);
 		Settings.uiSize = uiSize.getSelectedIndex();