/// <summary>
///
/// </summary>
/// <param name="envelope"></param>
/// <param name="rectangle"></param>
/// <returns></returns>
public static int DetermineZoomLevel(Envelope envelope, Rectangle rectangle)
{
double metersAcross = EarthRadiusKms * envelope.Width * Math.PI / 180; //find the arc length represented by the displayed map
metersAcross *= Math.Cos(envelope.Center().Y * Math.PI / 180); //correct for the center latitude
double metersAcrossPerPixel = metersAcross / rectangle.Width; //find the resolution in meters per pixel
//find zoomlevel such that metersAcrossPerPix is close
for (int i = 2; i < 19; i++)
{
double groundRes = GroundResolution(envelope.Center().Y, i);
if (metersAcrossPerPixel > groundRes)
{
//System.Diagnostics.Debug.WriteLine("metersPerPixel: " + metersAcrossPerPixel);
//System.Diagnostics.Debug.WriteLine("groundRes: " + groundRes);
//double ratio = metersAcrossPerPixel / groundRes;
//System.Diagnostics.Debug.WriteLine("ratio: " + ratio);
//fix zoom level..
//changed to a slightly lower zoom level to increase readability
if (i > 2 && i < 18) return i - 1;
////MessageBox.Show("MAPP: "+metersAcrossPerPixel+" , zoom: "+(i-1));
return i;
}
}
return -1;
}
/// <summary>
///
/// </summary>
/// <param name="envelope"></param>
/// <param name="rectangle"></param>
/// <returns></returns>
public static int DetermineZoomLevel(Envelope envelope, Rectangle rectangle)
{
double metersAcross = EarthRadiusKms * envelope.Width * Math.PI / 180; //find the arc length represented by the displayed map
metersAcross *= Math.Cos(envelope.Center().Y * Math.PI / 180); //correct for the center latitude
double metersAcrossPerPixel = metersAcross / rectangle.Width; //find the resolution in meters per pixel
//find zoomlevel such that metersAcrossPerPix is close
for (int i = 2; i < 19; i++)
{
double groundRes = GroundResolution(envelope.Center().Y, i);
if (metersAcrossPerPixel > groundRes)
{
//fix zoom level..
//changed to a slightly lower zoom level to increase readability
if (i > 2 && i < 18) return i - 1;
return i;
}
}
return -1;
}