/// <summary>
/// 经纬度坐标转像素坐标
/// </summary>
/// <returns></returns>
public static PointDouble LatLngToPixel(PointLatLng pLatLng, int zoom)
{
PointDouble pPix = new PointDouble();
if (pLatLng != null)
{
var lat = MapHelper.Clip(pLatLng.LatY, MinLatY, MaxLatY);
var lng = MapHelper.Clip(pLatLng.LngX, MinLngX, MaxLngX);
double x = (lng + 180) / 360;
double sinLatitude = Math.Sin(lat * Math.PI / 180);
double y = 0.5 - Math.Log((1 + sinLatitude) / (1 - sinLatitude)) / (4 * Math.PI);
BSize <long> s = MapHelper.GetTileMatrixSizePixel(zoom, TileSize);
double mapSizeX = s.Width;
double mapSizeY = s.Height;
//pPix.X = MapHelper.Clip(x * mapSizeX + 0.5, 0, mapSizeX - 1);
//pPix.Y = MapHelper.Clip(y * mapSizeY + 0.5, 0, mapSizeY - 1);
pPix.X = MapHelper.Clip(x * mapSizeX, 0, mapSizeX - 1);
pPix.Y = MapHelper.Clip(y * mapSizeY, 0, mapSizeY - 1);
}
return(pPix);
}
/// <summary>
/// 像素坐标转经纬度坐标
/// </summary>
/// <param name="x"></param>
/// <param name="y"></param>
/// <param name="zoom"></param>
/// <returns></returns>
public static PointLatLng PixelToLatLng(PointDouble pPix, int zoom)
{
PointLatLng ret = new PointLatLng();
if (pPix != null)
{
BSize <long> s = MapHelper.GetTileMatrixSizePixel(zoom, TileSize);
double mapSizeX = s.Width;
double mapSizeY = s.Height;
double xx = (MapHelper.Clip(pPix.X, 0, mapSizeX - 1) / mapSizeX) - 0.5;
double yy = 0.5 - (MapHelper.Clip(pPix.Y, 0, mapSizeY - 1) / mapSizeY);
ret.LatY = 90 - 360 * Math.Atan(Math.Exp(-yy * 2 * Math.PI)) / Math.PI;
ret.LngX = 360 * xx;
}
return(ret);
}
/// <summary>
/// 获取像素分辨率（每像素代表多少米）
/// </summary>
/// <param name="zoom">层级</param>
/// <param name="latitude">纬度</param>
/// <returns></returns>
public static double GetResolution(int zoom, double latitude)
{
return((Math.Cos(latitude * (Math.PI / 180)) * 2 * Math.PI * Axis) / MapHelper.GetTileMatrixSizePixel(zoom, TileSize).Width);
}
