altoslib: Preload maps based on distance rather than number of tiles

This lets you get the specific area requested at all zoom levels,
rather than having further detail only at lower resolution zooms.

Signed-off-by: Keith Packard <keithp@keithp.com>

6 files changed, 179 insertions, 33 deletions

diff --git a/altosdroid/res/layout/map_preload.xml b/altosdroid/res/layout/map_preload.xml
index 1d1fca32..dc613bf2 100644
--- a/altosdroid/res/layout/map_preload.xml
+++ b/altosdroid/res/layout/map_preload.xml
@@ -103,15 +103,15 @@
 	       android:prompt="@string/preload_max_zoom"
 	       android:spinnerMode="dropdown"
 	       />
-      <TextView android:id="@+id/preload_tile_radius_label"
+      <TextView android:id="@+id/preload_radius_label"
 		android:layout_width="fill_parent"
 		android:layout_height="wrap_content"
-		android:text="@string/preload_tile_radius"
+		android:text="@string/preload_radius"
 		/>
-      <Spinner android:id="@+id/preload_tile_radius"
+      <Spinner android:id="@+id/preload_radius"
 	       android:layout_width="fill_parent"
 	       android:layout_height="wrap_content"
-	       android:prompt="@string/preload_tile_radius"
+	       android:prompt="@string/preload_radius"
 	       android:spinnerMode="dropdown"
 	       />
       <Button android:id="@+id/preload_load"
diff --git a/altosdroid/res/values/strings.xml b/altosdroid/res/values/strings.xml
index 8c299a35..36b07bc2 100644
--- a/altosdroid/res/values/strings.xml
+++ b/altosdroid/res/values/strings.xml
@@ -106,7 +106,7 @@
 	<string name="preload_terrain">Terrain</string>
 	<string name="preload_min_zoom">Minimum Zoom</string>
 	<string name="preload_max_zoom">Maximum Zoom</string>
-	<string name="preload_tile_radius">Tile Radius</string>
+	<string name="preload_radius">Radius</string>
 	
 	<string name="preload_load">Load Map</string>
 </resources>
diff --git a/altosdroid/src/org/altusmetrum/AltosDroid/PreloadMapActivity.java b/altosdroid/src/org/altusmetrum/AltosDroid/PreloadMapActivity.java
index 1968edae..498b208e 100644
--- a/altosdroid/src/org/altusmetrum/AltosDroid/PreloadMapActivity.java
+++ b/altosdroid/src/org/altusmetrum/AltosDroid/PreloadMapActivity.java
@@ -61,7 +61,8 @@ public class PreloadMapActivity extends Activity implements AltosLaunchSiteListe
 	private Spinner		known_sites_spinner;
 	private Spinner		min_zoom;
 	private Spinner		max_zoom;
-	private Spinner		tile_radius;
+	private TextView	radius_label;
+	private Spinner		radius;
 
 	private EditText	latitude;
 	private EditText	longitude;
@@ -227,8 +228,17 @@ public class PreloadMapActivity extends Activity implements AltosLaunchSiteListe
 		return value(max_zoom);
 	}
 
-	private int radius() {
-		return value(tile_radius);
+	private double value_distance(Spinner spinner) {
+		return (Double) spinner.getSelectedItem();
+	}
+
+	private double radius() {
+		double r = value_distance(radius);
+		if (AltosPreferences.imperial_units())
+			r = AltosConvert.distance.inverse(r);
+		else
+			r = r * 1000;
+		return r;
 	}
 
 	private int bit(CheckBox box, int value) {
@@ -250,11 +260,14 @@ public class PreloadMapActivity extends Activity implements AltosLaunchSiteListe
 			double	lon = longitude();
 			int	min = min_z();
 			int	max = max_z();
-			int	r = radius();
+			double	r = radius();
 			int	t = types();
 
+			AltosDebug.debug("PreloadMap load %f %f %d %d %f %d\n",
+					 lat, lon, min, max, r, t);
 			loader.load(lat, lon, min, max, r, t);
 		} catch (ParseException e) {
+			AltosDebug.debug("PreloadMap load raised exception %s", e.toString());
 		}
 	}
 
@@ -276,6 +289,37 @@ public class PreloadMapActivity extends Activity implements AltosLaunchSiteListe
 		spinner.setSelection(spinner_def);
 	}
 
+
+	private void add_distance(Spinner spinner, double[] distances_km, double def_km, double[] distances_mi, double def_mi) {
+
+		ArrayAdapter<Double> adapter = new ArrayAdapter<Double>(this, android.R.layout.simple_spinner_item);
+
+		int	spinner_def = 0;
+		int	pos = 0;
+
+		double[] distances;
+		double	def;
+		if (AltosPreferences.imperial_units()) {
+			distances = distances_mi;
+			def = def_mi;
+		} else {
+			distances = distances_km;
+			def = def_km;
+		}
+
+		for (int i = 0; i < distances.length; i++) {
+			adapter.add(distances[i]);
+			if (distances[i] == def)
+				spinner_def = pos;
+			pos++;
+		}
+
+		spinner.setAdapter(adapter);
+		spinner.setSelection(spinner_def);
+	}
+
+
+
 	class SiteListListener implements OnItemSelectedListener {
 		public void onItemSelected(AdapterView<?> parent, View view, int pos, long id) {
 			AltosLaunchSite	site = (AltosLaunchSite) parent.getItemAtPosition(pos);
@@ -289,6 +333,11 @@ public class PreloadMapActivity extends Activity implements AltosLaunchSiteListe
 		}
 	}
 
+	double[]	radius_mi = { 1, 2, 5, 10, 20 };
+	double		radius_def_mi = 2;
+	double[]	radius_km = { 1, 2, 5, 10, 20, 30 };
+	double		radius_def_km = 2;
+
 	@Override
 	protected void onCreate(Bundle savedInstanceState) {
 		super.onCreate(savedInstanceState);
@@ -326,8 +375,13 @@ public class PreloadMapActivity extends Activity implements AltosLaunchSiteListe
 		add_numbers(max_zoom,
 			    AltosMap.min_zoom - AltosMap.default_zoom,
 			    AltosMap.max_zoom - AltosMap.default_zoom, 2);
-		tile_radius = (Spinner) findViewById(R.id.preload_tile_radius);
-		add_numbers(tile_radius, 1, 5, 5);
+		radius_label = (TextView) findViewById(R.id.preload_radius_label);
+		radius = (Spinner) findViewById(R.id.preload_radius);
+		if (AltosPreferences.imperial_units())
+			radius_label.setText("Radius (miles)");
+		else
+			radius_label.setText("Radius (km)");
+		add_distance(radius, radius_km, radius_def_km, radius_mi, radius_def_mi);
 
 		progress = (ProgressBar) findViewById(R.id.preload_progress);
 
diff --git a/altoslib/AltosMapLoader.java b/altoslib/AltosMapLoader.java
index cf7169ba..2cd5dbd3 100644
--- a/altoslib/AltosMapLoader.java
+++ b/altoslib/AltosMapLoader.java
@@ -24,7 +24,7 @@ import java.lang.Math;
 import java.net.URL;
 import java.net.URLConnection;
 
-public class AltosMapLoader implements AltosMapTileListener {
+public class AltosMapLoader implements AltosMapTileListener, AltosMapStoreListener {
 	AltosMapLoaderListener	listener;
 
 	double	latitude, longitude;
@@ -33,17 +33,71 @@ public class AltosMapLoader implements AltosMapTileListener {
 	int	cur_z;
 	int	all_types;
 	int	cur_type;
-	int	radius;
+	double	radius;
 
-	int	tiles_per_layer;
-	int	tiles_loaded;
+	int	tiles_loaded_layer;
+	int	tiles_loaded_total;
+	int	tiles_this_layer;
+	int	tiles_total;
 	int	layers_total;
 	int	layers_loaded;
 
 	AltosMap	map;
 
+	int tile_radius(int zoom) {
+		double	delta_lon = AltosMapTransform.lon_from_distance(latitude, radius);
+
+		AltosMapTransform t = new AltosMapTransform(256, 256, zoom + AltosMap.default_zoom, new AltosLatLon(latitude, longitude));
+
+		AltosPointDouble	center = t.point(new AltosLatLon(latitude, longitude));
+		AltosPointDouble	edge = t.point(new AltosLatLon(latitude, longitude + delta_lon));
+
+		int tile_radius = (int) Math.ceil(Math.abs(center.x - edge.x) / AltosMap.px_size);
+
+		return tile_radius;
+	}
+
+	int tiles_per_layer(int zoom) {
+		int	tile_radius = tile_radius(zoom);
+		return (tile_radius * 2 + 1) * (tile_radius * 2 + 1);
+	}
+
 	public void do_load() {
-		map.set_load_params(cur_z + AltosMap.default_zoom, cur_type, latitude, longitude, radius, this);
+		tiles_this_layer = tiles_per_layer(cur_z);
+		tiles_loaded_layer = 0;
+		listener.debug("tiles_this_layer %d (zoom %d)\n", tiles_this_layer, cur_z);
+
+		int load_radius = tile_radius(cur_z);
+		int zoom = cur_z + AltosMap.default_zoom;
+		int maptype = cur_type;
+		AltosLatLon load_centre = new AltosLatLon(latitude, longitude);
+		AltosMapTransform transform = new AltosMapTransform(256, 256, zoom, load_centre);
+
+		map.centre(load_centre);
+
+		AltosPointInt	upper_left;
+		AltosPointInt	lower_right;
+
+		AltosPointInt centre = AltosMap.floor(transform.point(load_centre));
+
+		upper_left = new AltosPointInt(centre.x - load_radius * AltosMap.px_size,
+					       centre.y - load_radius * AltosMap.px_size);
+		lower_right = new AltosPointInt(centre.x + load_radius * AltosMap.px_size,
+						centre.y + load_radius * AltosMap.px_size);
+
+
+		for (int y = (int) upper_left.y; y <= lower_right.y; y += AltosMap.px_size) {
+			for (int x = (int) upper_left.x; x <= lower_right.x; x += AltosMap.px_size) {
+				listener.debug("Make tile at %d, %d\n", x, y);
+				AltosPointInt	point = new AltosPointInt(x, y);
+				AltosLatLon	ul = transform.lat_lon(point);
+				AltosLatLon	center = transform.lat_lon(new AltosPointDouble(x + AltosMap.px_size/2, y + AltosMap.px_size/2));
+				AltosMapTile	tile = map.map_interface.new_tile(this, ul, center, zoom, maptype, AltosMap.px_size);
+				tile.add_store_listener(this);
+				if (tile.store_status() != AltosMapTile.loading)
+					notify_tile(tile, tile.store_status());
+			}
+		}
 	}
 
 	public int next_type(int start) {
@@ -84,16 +138,23 @@ public class AltosMapLoader implements AltosMapTileListener {
 		}
 
 		cur_type = next_type(0);
-		tiles_per_layer = (radius * 2 + 1) * (radius * 2 + 1);
+
+		for (int z = min_z; z <= max_z; z++)
+			tiles_total += tiles_per_layer(z);
+
 		layers_total = (max_z - min_z + 1) * ntype;
 		layers_loaded = 0;
-		tiles_loaded = 0;
+		tiles_loaded_total = 0;
+
+		listener.debug("total tiles %d\n", tiles_total);
 
-		listener.loader_start(layers_total * tiles_per_layer);
+		listener.loader_start(tiles_total);
 		do_load();
 	}
 
-	public void load(double latitude, double longitude, int min_z, int max_z, int radius, int all_types) {
+	public void load(double latitude, double longitude, int min_z, int max_z, double radius, int all_types) {
+		listener.debug("lat %f lon %f min_z %d max_z %d radius %f all_types %d\n",
+			       latitude, longitude, min_z, max_z, radius, all_types);
 		this.latitude = latitude;
 		this.longitude = longitude;
 		this.min_z = min_z;
@@ -103,7 +164,7 @@ public class AltosMapLoader implements AltosMapTileListener {
 		start_load();
 	}
 
-	public synchronized void notify_tile(AltosMapTile tile, int status) {
+	public synchronized void notify_store(AltosMapStore store, int status) {
 		boolean	do_next = false;
 		if (status == AltosMapTile.loading)
 			return;
@@ -111,24 +172,30 @@ public class AltosMapLoader implements AltosMapTileListener {
 		if (layers_loaded >= layers_total)
 			return;
 
-		++tiles_loaded;
+		++tiles_loaded_total;
+		++tiles_loaded_layer;
+		listener.debug("total %d layer %d\n", tiles_loaded_total, tiles_loaded_layer);
 
-		if (tiles_loaded == tiles_per_layer) {
-			tiles_loaded = 0;
+		if (tiles_loaded_layer == tiles_this_layer) {
 			++layers_loaded;
+			listener.debug("%d layers loaded\n", layers_loaded);
 			if (layers_loaded == layers_total) {
-				listener.loader_done(layers_total * tiles_per_layer);
+				listener.loader_done(tiles_total);
 				return;
 			} else {
 				do_next = true;
 			}
 		}
-		listener.loader_notify(layers_loaded * tiles_per_layer + tiles_loaded,
-				       layers_total * tiles_per_layer, tile.store.file.toString());
+		listener.loader_notify(tiles_loaded_total,
+				       tiles_total, store.file.toString());
 		if (do_next)
 			next_load();
 	}
 
+	public synchronized void notify_tile(AltosMapTile tile, int status) {
+		notify_store(tile.store, status);
+	}
+
 	public AltosMapCache cache() { return map.cache(); }
 
 	public AltosMapLoader(AltosMap map, AltosMapLoaderListener listener) {
diff --git a/altoslib/AltosMapLoaderListener.java b/altoslib/AltosMapLoaderListener.java
index 79f8b9df..11f59b28 100644
--- a/altoslib/AltosMapLoaderListener.java
+++ b/altoslib/AltosMapLoaderListener.java
@@ -23,4 +23,6 @@ public interface AltosMapLoaderListener {
 	public abstract void loader_notify(int cur, int max, String name);
 
 	public abstract void loader_done(int max);
+
+	public abstract void debug(String format, Object ... arguments);
 }
diff --git a/altosuilib/AltosUIMapPreloadNew.java b/altosuilib/AltosUIMapPreloadNew.java
index 4a5764c8..ba559534 100644
--- a/altosuilib/AltosUIMapPreloadNew.java
+++ b/altosuilib/AltosUIMapPreloadNew.java
@@ -140,10 +140,15 @@ public class AltosUIMapPreloadNew extends AltosUIFrame implements ActionListener
 
 	JComboBox<Integer>	min_zoom;
 	JComboBox<Integer>	max_zoom;
-	JComboBox<Integer>	radius;
+	JComboBox<Double>	radius;
 
 	Integer[]		zooms = { -12, -11, -10, -9, -8, -7, -6, -5, -4, -3, -2, -1, 0, 1, 2, 3, 4, 5, 6 };
-	Integer[]		radii = { 1, 2, 3, 4, 5 };
+
+	Double[]	radius_mi = { 1.0, 2.0, 5.0, 10.0, 20.0 };
+	Double		radius_def_mi = 5.0;
+	Double[]	radius_km = { 2.0, 5.0, 10.0, 20.0, 30.0 };
+	Double		radius_def_km = 10.0;
+
 
 	static final String[]	lat_hemi_names = { "N", "S" };
 	static final String[]	lon_hemi_names = { "E", "W" };
@@ -183,6 +188,11 @@ public class AltosUIMapPreloadNew extends AltosUIFrame implements ActionListener
 			});
 	}
 
+	public void debug(String format, Object ... arguments) {
+		System.out.printf(format, arguments);
+	}
+
+
 	private int all_types() {
 		int all_types = 0;
 		for (int t = AltosMap.maptype_hybrid; t <= AltosMap.maptype_terrain; t++)
@@ -219,7 +229,12 @@ public class AltosUIMapPreloadNew extends AltosUIFrame implements ActionListener
 					int max_z = (Integer) max_zoom.getSelectedItem();
 					if (max_z < min_z)
 						max_z = min_z;
-					int r = (Integer) radius.getSelectedItem();
+					Double r = (Double) radius.getSelectedItem();
+
+					if (AltosPreferences.imperial_units())
+						r = AltosConvert.distance.inverse(r);
+					else
+						r = r * 1000;
 					loading = true;
 
 					loader.load(latitude, longitude, min_z, max_z, r, all_types());
@@ -430,13 +445,21 @@ public class AltosUIMapPreloadNew extends AltosUIFrame implements ActionListener
 		c.gridy = 3;
 		pane.add(max_zoom, c);
 
-		JLabel radius_label = new JLabel("Tile Radius");
+		JLabel radius_label = new JLabel(String.format("Map Radius (%s)",
+							       AltosPreferences.imperial_units() ? "miles" : "km"));
 		c.gridx = 4;
 		c.gridy = 4;
 		pane.add(radius_label, c);
 
-		radius = new JComboBox<Integer>(radii);
-		radius.setSelectedItem(radii[4]);
+		Double[]	radii;
+		Double		radius_default;
+
+		if (AltosPreferences.imperial_units())
+			radii = radius_mi;
+		else
+			radii = radius_km;
+		radius = new JComboBox<Double>(radii);
+		radius.setSelectedItem(radii[2]);
 		radius.setEditable(true);
 		c.gridx = 5;
 		c.gridy = 4;