start TileLoaderHook:

- only create ExtrusionLayers when a BuildingLayer is attached

vtm/src/org/oscim/layers/tile/vector/BuildingLayer.java

@@ -16,19 +16,30 @@
  */
 package org.oscim.layers.tile.vector;
 
+import org.oscim.core.MapElement;
+import org.oscim.core.MercatorProjection;
+import org.oscim.core.Tag;
 import org.oscim.layers.Layer;
+import org.oscim.layers.tile.MapTile;
+import org.oscim.layers.tile.vector.VectorTileLayer.TileLoaderHook;
 import org.oscim.map.Map;
 import org.oscim.renderer.ExtrusionRenderer;
 import org.oscim.renderer.GLViewport;
+import org.oscim.renderer.elements.ElementLayers;
+import org.oscim.renderer.elements.ExtrusionLayer;
+import org.oscim.theme.styles.ExtrusionStyle;
+import org.oscim.theme.styles.RenderStyle;
 import org.oscim.utils.FastMath;
 
-public class BuildingLayer extends Layer {
+public class BuildingLayer extends Layer implements TileLoaderHook {
 	//static final Logger log = LoggerFactory.getLogger(BuildingOverlay.class);
 
 	final ExtrusionRenderer mExtLayer;
 
 	public BuildingLayer(Map map, VectorTileLayer tileLayer) {
 		super(map);
+		tileLayer.addHook(this);
+
 		mExtLayer = new ExtrusionRenderer(tileLayer.tileRenderer()) {
 			private long mStartTime;
 
@@ -79,6 +90,43 @@ public class BuildingLayer extends Layer {
 
 	private final static int MIN_ZOOM = 17;
 
+	@Override
+	public void render(MapTile tile, ElementLayers layers, MapElement element,
+	        RenderStyle style, int level) {
+
+		if (!(style instanceof ExtrusionStyle))
+			return;
+
+		ExtrusionStyle extrusion = (ExtrusionStyle) style;
+
+		int height = 0;
+		int minHeight = 0;
+
+		String v = element.tags.getValue(Tag.KEY_HEIGHT);
+		if (v != null)
+			height = Integer.parseInt(v);
+		v = element.tags.getValue(Tag.KEY_MIN_HEIGHT);
+		if (v != null)
+			minHeight = Integer.parseInt(v);
+
+		ExtrusionLayer l = layers.getExtrusionLayers();
+
+		if (l == null) {
+			double lat = MercatorProjection.toLatitude(tile.y);
+			float groundScale = (float) MercatorProjection
+			    .groundResolution(lat, 1 << tile.zoomLevel);
+
+			l = new ExtrusionLayer(0, groundScale, extrusion.colors);
+			layers.setExtrusionLayers(l);
+		}
+
+		/* 12m default */
+		if (height == 0)
+			height = 12 * 100;
+
+		l.add(element, height, minHeight);
+	}
+
 	//@Override
 	//public boolean onTouchEvent(MotionEvent e) {
 	//	int action = e.getAction() & MotionEvent.ACTION_MASK;

vtm/src/org/oscim/layers/tile/vector/VectorTileLayer.java

@@ -16,12 +16,16 @@
  */
 package org.oscim.layers.tile.vector;
 
+import org.oscim.core.MapElement;
+import org.oscim.layers.tile.MapTile;
 import org.oscim.layers.tile.TileLayer;
 import org.oscim.layers.tile.TileLoader;
 import org.oscim.layers.tile.TileManager;
 import org.oscim.layers.tile.VectorTileRenderer;
 import org.oscim.map.Map;
+import org.oscim.renderer.elements.ElementLayers;
 import org.oscim.theme.IRenderTheme;
+import org.oscim.theme.styles.RenderStyle;
 import org.oscim.tiling.TileSource;
 import org.oscim.tiling.TileSource.OpenResult;
 import org.slf4j.Logger;
@@ -118,4 +122,24 @@ public class VectorTileLayer extends TileLayer {
 	public IRenderTheme getTheme() {
 		return mTheme;
 	}
+
+	public interface TileLoaderHook {
+		public void render(MapTile tile, ElementLayers layers,
+		        MapElement element, RenderStyle style, int level);
+	}
+
+	private TileLoaderHook[] mLoaderHooks = new TileLoaderHook[0];
+
+	public TileLoaderHook[] getLoaderHooks() {
+		return mLoaderHooks;
+	}
+
+	public void addHook(TileLoaderHook h) {
+		int length = mLoaderHooks.length;
+		TileLoaderHook[] tmp = new TileLoaderHook[length + 1];
+		System.arraycopy(mLoaderHooks, 0, tmp, 0, length);
+		tmp[length] = h;
+		mLoaderHooks = tmp;
+	}
+
 }

vtm/src/org/oscim/layers/tile/vector/VectorTileLoader.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2012, 2013 Hannes Janetzek
+ * Copyright 2012-2014 Hannes Janetzek
  *
  * This file is part of the OpenScienceMap project (http://www.opensciencemap.org).
  *
@@ -28,8 +28,8 @@ import org.oscim.core.Tag;
 import org.oscim.core.TagSet;
 import org.oscim.layers.tile.MapTile;
 import org.oscim.layers.tile.TileLoader;
+import org.oscim.layers.tile.vector.VectorTileLayer.TileLoaderHook;
 import org.oscim.renderer.elements.ElementLayers;
-import org.oscim.renderer.elements.ExtrusionLayer;
 import org.oscim.renderer.elements.LineLayer;
 import org.oscim.renderer.elements.LineTexLayer;
 import org.oscim.renderer.elements.MeshLayer;
@@ -346,10 +346,6 @@ public class VectorTileLoader extends TileLoader implements IRenderTheme.Callbac
 		}
 	}
 
-	@Override
-	public void renderPointCircle(CircleStyle circle, int level) {
-	}
-
 	@Override
 	public void renderPointSymbol(SymbolStyle symbol) {
 		if (symbol.texture == null)
@@ -364,37 +360,16 @@ public class VectorTileLoader extends TileLoader implements IRenderTheme.Callbac
 		}
 	}
 
+	public void renderExtrusion(ExtrusionStyle extrusion, int level) {
+		for (TileLoaderHook h : mTileLayer.getLoaderHooks())
+			h.render(mTile, mLayers, mElement, extrusion, level);
+	}
+
 	@Override
 	public void renderAreaSymbol(SymbolStyle symbol) {
 	}
 
 	@Override
-	public void renderExtrusion(ExtrusionStyle extrusion, int level) {
+	public void renderPointCircle(CircleStyle circle, int level) {
-		int height = 0;
-		int minHeight = 0;
-
-		String v = mElement.tags.getValue(Tag.KEY_HEIGHT);
-		if (v != null)
-			height = Integer.parseInt(v);
-		v = mElement.tags.getValue(Tag.KEY_MIN_HEIGHT);
-		if (v != null)
-			minHeight = Integer.parseInt(v);
-
-		ExtrusionLayer l = mLayers.getExtrusionLayers();
-
-		if (l == null) {
-			double lat = MercatorProjection.toLatitude(mTile.y);
-			float groundScale = (float) MercatorProjection
-			    .groundResolution(lat, 1 << mTile.zoomLevel);
-
-			l = new ExtrusionLayer(0, groundScale, extrusion.colors);
-			mLayers.setExtrusionLayers(l);
-		}
-
-		/* 12m default */
-		if (height == 0)
-			height = 12 * 100;
-
-		l.add(mElement, height, minHeight);
 	}
 }