add examples

vtm-jeo/src/org/oscim/layers/JtsLayer.java

@@ -0,0 +1,102 @@
+package org.oscim.layers;
+
+import org.jeo.geom.CoordinatePath;
+import org.oscim.core.BoundingBox;
+import org.oscim.core.GeometryBuffer;
+import org.oscim.core.MapPosition;
+import org.oscim.core.MercatorProjection;
+import org.oscim.core.Tile;
+import org.oscim.layers.vector.AbstractVectorLayer;
+import org.oscim.map.Map;
+import org.oscim.renderer.elements.LineLayer;
+import org.oscim.renderer.elements.MeshLayer;
+import org.oscim.utils.geom.SimplifyDP;
+import org.oscim.utils.geom.SimplifyVW;
+
+import com.vividsolutions.jts.geom.Coordinate;
+import com.vividsolutions.jts.geom.Envelope;
+import com.vividsolutions.jts.geom.Geometry;
+
+public abstract class JtsLayer extends AbstractVectorLayer<Geometry> {
+
+	public JtsLayer(Map map) {
+		super(map);
+	}
+
+	@Override
+	protected void processFeatures(Task t, BoundingBox bbox) {
+		processFeatures(t, new Envelope(bbox.getMinLongitude(), bbox.getMaxLongitude(),
+		                                bbox.getMinLatitude(), bbox.getMaxLatitude()));
+
+	}
+
+	protected abstract void processFeatures(Task t, Envelope e);
+
+	protected int transformPath(MapPosition pos, GeometryBuffer g, CoordinatePath path) {
+
+		double scale = pos.scale * Tile.SIZE / UNSCALE_COORD;
+		int cnt = 0;
+		O: while (path.hasNext()) {
+			Coordinate c = path.next();
+			float x = (float) ((MercatorProjection.longitudeToX(c.x) - pos.x) * scale);
+			float y = (float) ((MercatorProjection.latitudeToY(c.y) - pos.y) * scale);
+
+			switch (path.getStep()) {
+				case MOVE_TO:
+					if (g.isPoly())
+						g.startPolygon();
+					else if (g.isLine())
+						g.startLine();
+
+					cnt++;
+					g.addPoint(x, y);
+					break;
+				case LINE_TO:
+					cnt++;
+					g.addPoint(x, y);
+					break;
+				case CLOSE:
+					//g.addPoint(x, y);
+					//if (g.type == GeometryType.POLY)
+					break;
+				case STOP:
+					break O;
+			}
+		}
+		return cnt;
+	}
+
+	SimplifyDP mSimpDP = new SimplifyDP();
+	SimplifyVW mSimpVW = new SimplifyVW();
+
+	protected void addPolygon(Task t, Geometry g, MeshLayer ml, LineLayer ll) {
+		mGeom.clear();
+		mGeom.startPolygon();
+
+		CoordinatePath p = CoordinatePath.create(g);
+		if (mMinX > 0 || mMinY > 0)
+			p.generalize(mMinX, mMinY);
+
+		if (transformPath(t.position, mGeom, p) < 3)
+			return;
+
+		if (!mClipper.clip(mGeom))
+			return;
+
+		mSimpVW.simplify(mGeom, 0.1f);
+		mSimpDP.simplify(mGeom, 0.5f);
+
+		ll.addLine(mGeom);
+		ml.addMesh(mGeom);
+	}
+
+	protected void addLine(Task t, Geometry g, LineLayer ll) {
+		mGeom.clear();
+		mGeom.startLine();
+
+		CoordinatePath p = CoordinatePath.create(g);
+		transformPath(t.position, mGeom, p);
+
+		ll.addLine(mGeom);
+	}
+}