/// <summary>
/// 中心地（経緯度）と中心地からの範囲（経緯度差）による矩形領域について
/// DEM を切り出し・合成して取得する
/// </summary>
/// <param name="z">Z</param>
/// <param name="center">中心地</param>
/// <param name="delta">中心地からの範囲（経緯度差）</param>
/// <param name="dem_type">対象とするDEM群</param>
/// <returns>標高群</returns>
public static double[,] LoadDEM
(byte z
, ILonLatGettable center
, ILonLatGettable delta
, DEMType dem_type = DEMType.DEM_5A_5B_10B
)
{
// 緯度軸方向の北端と南端を確定
var dlatabs = delta.Latitude.Abs();
var north_angle = (center.Latitude + dlatabs).Normalize180();
var south_angle = (center.Latitude - dlatabs).Normalize180();
// 経度軸方向の西端と東端を確定
var dlonabs = delta.Longitude.Abs();
var east_angle = (center.Longitude + dlonabs).Normalize360();
var west_angle = (center.Longitude - dlonabs).Normalize360();
//Console.WriteLine( $"e={east_angle}" );
//Console.WriteLine( $"w={west_angle}" );
//Console.WriteLine( $"n={north_angle}" );
//Console.WriteLine( $"s={south_angle}" );
// 東端・北端のピクセルを確定
var north_east_pixel = WebMercator.AngleToPixel(new LonLat(east_angle, north_angle), z);
// 西端・南端のピクセルを確定
var south_west_pixel = WebMercator.AngleToPixel(new LonLat(west_angle, south_angle), z);
//Console.WriteLine( $"N-E px = {north_east_pixel}" );
//Console.WriteLine( $"S-W px = {south_west_pixel}" );
// 東端・北端のタイルを確定
var north_east_tile = WebMercator.PixelToTile(north_east_pixel);
// 西端・南端のタイルを確定
var south_west_tile = WebMercator.PixelToTile(south_west_pixel);
//Console.WriteLine( $"N-E tile = {north_east_tile}" );
//Console.WriteLine( $"S-W tile = {south_west_tile}" );
// 最終的に必要なピクセル群のX軸サイズ; 区間 [ west ... east ] なのでサイズは +1
// west < east
var target_pixel_size_x = ( int )(north_east_pixel.X - south_west_pixel.X + 1);
// 最終的に必要なピクセル群のY軸サイズ; 区間 [ north ... south ] なのでサイズは +1
// north < south
var target_pixel_size_y = ( int )(south_west_pixel.Y - north_east_pixel.Y + 1);
// 出力用のバッファー
var r = new double[target_pixel_size_x, target_pixel_size_y];
// 北西から南東へ
{
// r 開始地点と data 開始地点のずれを計算
const int tile_pixel_shift = 8;
const int data_arris_size = 1 << tile_pixel_shift;
var dpx = (int)(south_west_tile.X << tile_pixel_shift) - (int)south_west_pixel.X;
var dpy = (int)(north_east_tile.Y << tile_pixel_shift) - (int)north_east_pixel.Y;
var t = new TileLocation(0, 0, z);
// data ごとの r 開始位置を dp だけずらしておく
var rx_begin = dpx;
var ry_begin = dpy;
for
(t.Y = north_east_tile.Y
; t.Y <= south_west_tile.Y
; ++t.Y, ry_begin += data_arris_size, rx_begin = dpx
)
{
for
(t.X = south_west_tile.X
; t.X <= north_east_tile.X
; ++t.X, rx_begin += data_arris_size
)
{
// デコードして
var data = LoadDEM(t, dem_type);
//using ( var i = SavePNGNumberTileS( data, 1.0e-2, 0, Color.FromArgb( 255, 128, 0, 0 ) ) )
// i.Save( System.IO.Path.Combine( System.Environment.GetFolderPath( System.Environment.SpecialFolder.DesktopDirectory ), $"GK/tmp/gyoe-{t.X}-{t.Y}-{t.Z}.png" ), System.Drawing.Imaging.ImageFormat.Png );
Func <int, int, double> sampler = (dx, dy) => data[dx, dy];
if (data == null)
{
sampler = (dx, dy) => double.NaN;
}
// r の適切な領域へ data をコピー
var rx = rx_begin;
var ry = ry_begin;
//Console.WriteLine( $"t={t} rx_begin={rx_begin} ry_begin={ry_begin}" );
for (var dy = 0; dy < data_arris_size; ++dy, ++ry, rx = rx_begin)
{
if (ry < 0 || ry >= r.GetLength(1))
{
continue;
}
else
{
for (var dx = 0; dx < data_arris_size; ++dx, ++rx)
{
if (rx < 0 || rx >= r.GetLength(0))
{
continue;
}
else
{
//{
r[rx, ry] = sampler(dx, dy);
}
}
}
}
//Console.WriteLine( $"rx={rx} ry={ry} dx={dx} dy={dy} value={data[ dx, dy ]}" );
//}
}
}
}
return(r);
}
