Problems with Google Maps API in Java ME

[tatranky]

Hi there,

I'm making an application witch uses the Google Maps static api, i used the code example from the article:
Google Maps API in Java ME

My problem is that i have a list of waypoints in the format (lat,lng) and i need the get the position of the points on the static map in pixels... I tried to convert the code from the page that the article also links to(http://home.provide.net/~bratliff/adjust.js) but it dosn't work when i need to lat/lng to x/y...

here's my code that should do the same at adjust.js:

public static GPSPoint XYtoLL(GPSPoint mapCenter, int deltaX, int deltaY, int zoom){
    	return new GPSPoint(
    			YToL(LToY(mapCenter.getLat()) + (deltaY<<(21-zoom))), 
    			XToL(LToX(mapCenter.getLng()) + (deltaX<<(21-zoom)))
    			);
    	
    }
    
    public static Point LLtoXY(GPSPoint mapCenter, GPSPoint point, int zoom){
    	return new Point(
    			(int)round(Double.doubleToLongBits((LToX(point.getLng())-LToX(mapCenter.getLng()))) >> (21-zoom)),
    			(int)round(Double.doubleToLongBits((LToY(point.getLat())-LToY(mapCenter.getLat())))>>(21-zoom))
    	);
    }

static double LToX(double x)
    {
    	return round(offset + radius * x * Math.PI / 180);
    }
     
    static double LToY(double y)
    {
    	return round(
    		offset - radius * 
    		Double.longBitsToDouble(MicroDouble.log(
    			Double.doubleToLongBits(
    			(1 + Math.sin(y * Math.PI / 180))
    			/
    			(1 - Math.sin(y * Math.PI / 180))
    			)
    		)) / 2);
    }
     
    static double XToL(double x)
    {
    	return ((round(x) - offset) / radius) * 180 / Math.PI;
    }
     
    static double YToL(double y)
    {
    	return (Math.PI / 2 - 2 * Double.longBitsToDouble(
    				MicroDouble.atan(
    					MicroDouble.exp(Double.doubleToLongBits((round(y)-offset)/radius))
    				)
    			)) * 180 / Math.PI;
    }
    static double round(double num)
    {
    	double floor = Math.floor(num);
     
    	if(num - floor >= 0.5)
    		return Math.ceil(num);
    	else
    		return floor;
    }

GPSPoint consists of two doubles... (lat and lng)

the XYtoLL works perfekt... but the LLtoXY doesn't...

here's two results og the LLtoXY:

1. input LL: (57.69255211496328 | 10.51119089126587) out xy-2147483349,-2147483383)
2. input LL: (57.54546006577498 | 10.32991647720337) out xy-2147483349,-2147483383)

Can anyone tell me what I'm doing Wrong?

[Tiger79]

I don't see a LLtoXY method...

[tatranky]

Tiger79: It's the second method:

and here it is again:

public static Point LLtoXY(GPSPoint mapCenter, GPSPoint point, int zoom){
    	return new Point(
    			(int)round(Double.doubleToLongBits((LToX(point.getLng())-LToX(mapCenter.getLng()))) >> (21-zoom)),
    			(int)round(Double.doubleToLongBits((LToY(point.getLat())-LToY(mapCenter.getLat())))>>(21-zoom))
    	);
    }

[Tiger79]

have you tried single-stepping through the code with a calculator by hand and check where the calculations go wrong ?
you do know what is getting calculated exactly ? Or did you just copy-paste the code without knowing why specific calculations are done ?
ANyways, single-stepping and looking at the value of every variable would seem the most logical thing to me...

[tatranky]

Well,

my problem is that i don't know the defenition og the gMaps zoom level, and therefor doesn't understandt that part of the calculation... i think the problem lies with the zoom level...