From 162838bb305f0cb4351915dd29e9e3462216afdf Mon Sep 17 00:00:00 2001
From: arlas <arlas@libero.it>
Date: Mon, 19 Sep 2011 00:36:56 +0300
Subject: [PATCH] edit squareroots and proposal for offline routing

---
 .../net/osmand/router/BinaryRoutePlanner.java | 45 ++++++++++++-------
 1 file changed, 30 insertions(+), 15 deletions(-)

diff --git a/DataExtractionOSM/src/net/osmand/router/BinaryRoutePlanner.java b/DataExtractionOSM/src/net/osmand/router/BinaryRoutePlanner.java
index 25c4f95ddf..801daa10f2 100644
--- a/DataExtractionOSM/src/net/osmand/router/BinaryRoutePlanner.java
+++ b/DataExtractionOSM/src/net/osmand/router/BinaryRoutePlanner.java
@@ -45,6 +45,13 @@ public class BinaryRoutePlanner {
 		return Math.sqrt(dx * dx + dy * dy);
 	}
 	
+	private static double squareDist(int x1, int y1, int x2, int y2) {
+		// translate into meters 
+		double dy = convert31YToMeters(y1, y2);
+		double dx = convert31XToMeters(x1, x2);
+		return dx * dx + dy * dy;
+	}
+	
 	private static double convert31YToMeters(int y1, int y2) {
 		// translate into meters 
 		return (y1 - y2) * 0.01863d;
@@ -117,12 +124,19 @@ public class BinaryRoutePlanner {
 	}
 	
 	// calculate distance from C to AB (distnace doesn't calculate 
-    private static double calculateDistance(int xA, int yA, int xB, int yB, int xC, int yC, double distAB){
-    	// Scalar multiplication between (AB', AC)
-    	double multiple = (-convert31YToMeters(yB, yA)) * convert31XToMeters(xC,xA) + convert31XToMeters(xB,xA) * convert31YToMeters(yC, yA);
-    	return multiple / distAB;
-    }
+	private static double calculateDistance(int xA, int yA, int xB, int yB, int xC, int yC, double distAB){
+	    	// Scalar multiplication between (AB', AC)
+	    	double multiple = (-convert31YToMeters(yB, yA)) * convert31XToMeters(xC,xA) + convert31XToMeters(xB,xA) * convert31YToMeters(yC, yA);
+	    	return multiple / distAB;
+	}
     
+	    // calculate square distance from C to AB (distance doesn't calculate 
+	private static double calculatesquareDistance(int xA, int yA, int xB, int yB, int xC, int yC, double distAB) {
+    	// Scalar multiplication between (AB', AC)
+		double multiple = (-convert31YToMeters(yB, yA)) * convert31XToMeters(xC,xA) + convert31XToMeters(xB,xA) * convert31YToMeters(yC, yA);
+		return (multiple * multiple) / (distAB*distAB);
+	}
+	
 	private static double calculateProjection(int xA, int yA, int xB, int yB, int xC, int yC, double distAB) {
 		// Scalar multiplication between (AB, AC)
 		double multiple = convert31XToMeters(xB, xA) * convert31XToMeters(xC, xA) + convert31YToMeters(yB, yA) * convert31YToMeters(yC, yA);
@@ -136,7 +150,7 @@ public class BinaryRoutePlanner {
 		loadRoutes(ctx, (int) tileX , (int) tileY);
 		
 		RouteSegment road = null;
-		double dist = 0; 
+		double sdist = 0; 
 		int px = MapUtils.get31TileNumberX(lon);
 		int py = MapUtils.get31TileNumberY(lat);
 		for(BinaryMapDataObject r : ctx.values()){
@@ -146,22 +160,23 @@ public class BinaryRoutePlanner {
 					double mDist = squareRootDist(r.getPoint31XTile(j), r.getPoint31YTile(j), r.getPoint31XTile(j - 1), r.getPoint31YTile(j - 1));
 					double projection = calculateProjection(r.getPoint31XTile(j - 1), r.getPoint31YTile(j - 1), r.getPoint31XTile(j), r.getPoint31YTile(j),
 							px, py, mDist);
-					double currentDist;
-					if(projection < 0){
-						currentDist = squareRootDist(r.getPoint31XTile(j - 1), r.getPoint31YTile(j - 1), px, py) / priority;
+					double currentsDist;
+					if(projection < 0){//TODO: first 2 and last 2 points of a route should be only near and not based on road priority (I.E. a motorway road node unreachable near my house)
+						currentsDist = squareDist(r.getPoint31XTile(j - 1), r.getPoint31YTile(j - 1), px, py) / (priority * priority);
 					} else if(projection > mDist){
-						currentDist = squareRootDist(r.getPoint31XTile(j), r.getPoint31YTile(j), px, py) / priority;
+						currentsDist = squareDist(r.getPoint31XTile(j), r.getPoint31YTile(j), px, py) / (priority * priority);
 					} else {
-						currentDist = Math.abs(calculateDistance(r.getPoint31XTile(j - 1), r.getPoint31YTile(j - 1), r.getPoint31XTile(j), r.getPoint31YTile(j),
-								px, py, mDist)) / priority;
+						currentsDist = calculatesquareDistance(r.getPoint31XTile(j - 1), r.getPoint31YTile(j - 1), r.getPoint31XTile(j), r.getPoint31YTile(j),
+								px, py, mDist) / (priority * priority);
 					}
 					
-					if (road == null || currentDist < dist) {
+					if (road == null || currentsDist < sdist) {
 						road = new RouteSegment();
 						road.road = r;
-						road.segmentStart = j - 1;
+						road.segmentStart = j - 1;//TODO: first 2 and last 2 segments should be based on projection. my start/finish point S/F, fake point P between j-1 & j -> SP, PJ; should end at finish point: JP,PF
+
 						road.segmentEnd = j;
-						dist = currentDist;
+						sdist = currentsDist;
 					}
 				}
 			}