public static srtm.altresponce getAltitude(double lat, double lng, double zoom = 16)
{
var answer = new srtm.altresponce();
foreach (var geotiffdata in index)
{
if (geotiffdata.Area.Contains(lat, lng))
{
// add to cache
if (!cache.ContainsKey(geotiffdata.FileName))
{
short[,] altdata = new short[geotiffdata.width, geotiffdata.height];
using (Tiff tiff = Tiff.Open(geotiffdata.FileName, "r"))
{
byte[] scanline = new byte[tiff.ScanlineSize()];
for (int row = 0; row < geotiffdata.height; row++)
{
tiff.ReadScanline(scanline, row);
for (int col = 0; col < geotiffdata.width; col++)
{
altdata[row, col] = (short)((scanline[col * 2 + 1] << 8) + scanline[col * 2]);
}
}
}
cache[geotiffdata.FileName] = altdata;
}
// get answer
var xf = map(lat, geotiffdata.Area.Top, geotiffdata.Area.Bottom, 0, geotiffdata.height);
var yf = map(lng, geotiffdata.Area.Left, geotiffdata.Area.Right, 0, geotiffdata.width);
int x_int = (int)xf;
double x_frac = xf - x_int;
int y_int = (int)yf;
double y_frac = yf - y_int;
// y_int = (geotiffdata.height - 2) - y_int;
double alt00 = GetAlt(geotiffdata.FileName, x_int, y_int);
double alt10 = GetAlt(geotiffdata.FileName, x_int + 1, y_int);
double alt01 = GetAlt(geotiffdata.FileName, x_int, y_int + 1);
double alt11 = GetAlt(geotiffdata.FileName, x_int + 1, y_int + 1);
double v1 = avg(alt00, alt10, x_frac);
double v2 = avg(alt01, alt11, x_frac);
double v = avg(v1, v2, -y_frac);
if (v > -1000)
{
answer.currenttype = srtm.tiletype.valid;
}
answer.alt = v;
return(answer);
}
}
return(new srtm.altresponce());
}
public static srtm.altresponce getAltitude(double lat, double lng, double zoom = 16)
{
lock (index)
if (index.Count == 0)
{
return(srtm.altresponce.Invalid);
}
var answer = new srtm.altresponce();
foreach (var geotiffdata in index.ToArray())
{
if (geotiffdata.Area.Contains(lat, lng))
{
// get answer
var xf = map(lat, geotiffdata.Area.Top, geotiffdata.Area.Bottom, 0, geotiffdata.height - 1);
var yf = map(lng, geotiffdata.Area.Left, geotiffdata.Area.Right, 0, geotiffdata.width - 1);
//wgs84 && etrs89
if (geotiffdata.ProjectedCSTypeGeoKey >= 3038 && geotiffdata.ProjectedCSTypeGeoKey <= 3051 ||
geotiffdata.ProjectedCSTypeGeoKey >= 32601 && geotiffdata.ProjectedCSTypeGeoKey <= 32760 ||
geotiffdata.ProjectedCSTypeGeoKey >= 25828 && geotiffdata.ProjectedCSTypeGeoKey <= 25838)
{
var pnt = PointLatLngAlt.ToUTM((geotiffdata.UTMZone) * 1, lat, lng);
xf = map(pnt[1], geotiffdata.y, geotiffdata.y - geotiffdata.height * geotiffdata.yscale, 0,
geotiffdata.height - 1);
yf = map(pnt[0], geotiffdata.x, geotiffdata.x + geotiffdata.width * geotiffdata.xscale, 0,
geotiffdata.width - 1);
}
int x_int = (int)xf;
double x_frac = xf - x_int;
int y_int = (int)yf;
double y_frac = yf - y_int;
//could be on one of the other images
if (x_int < 0 || y_int < 0 || x_int >= geotiffdata.width - 1 || y_int >= geotiffdata.height - 1)
{
continue;
}
double alt00 = GetAlt(geotiffdata, x_int, y_int);
double alt10 = GetAlt(geotiffdata, x_int + 1, y_int);
double alt01 = GetAlt(geotiffdata, x_int, y_int + 1);
double alt11 = GetAlt(geotiffdata, x_int + 1, y_int + 1);
double v1 = avg(alt00, alt10, x_frac);
double v2 = avg(alt01, alt11, x_frac);
double v = avg(v1, v2, y_frac);
if (v > -1000)
{
answer.currenttype = srtm.tiletype.valid;
}
if (alt00 < -1000 || alt10 < -1000 || alt01 < -1000 || alt11 < -1000)
{
answer.currenttype = srtm.tiletype.invalid;
}
answer.alt = v;
answer.altsource = "GeoTiff";
return(answer);
}
}
return(srtm.altresponce.Invalid);
}
public static srtm.altresponce getAltitude(double lat, double lng, double zoom = 16)
{
lock (index)
if (index.Count == 0)
{
return(srtm.altresponce.Invalid);
}
var answer = new srtm.altresponce();
foreach (var geotiffdata in index.ToArray())
{
if (geotiffdata.Area.Contains(lat, lng))
{
// add to cache
if (!cache.ContainsKey(geotiffdata.FileName) && geotiffdata.cacheable)
{
if (!File.Exists(geotiffdata.FileName))
{
continue;
}
lock (cacheloading)
{
if (cacheloading.Contains(geotiffdata.FileName))
{
return(srtm.altresponce.Invalid);
}
cacheloading.Add(geotiffdata.FileName);
}
Task.Run(() => {
try
{
float[,] altdata = new float[geotiffdata.height, geotiffdata.width];
using (Tiff tiff = Tiff.Open(geotiffdata.FileName, "r"))
{
if (tiff.GetField(TiffTag.TILEWIDTH) != null &&
tiff.GetField(TiffTag.TILEWIDTH).Length >= 1)
{
FieldValue[] value = tiff.GetField(TiffTag.IMAGEWIDTH);
int imageWidth = value[0].ToInt();
value = tiff.GetField(TiffTag.IMAGELENGTH);
int imageLength = value[0].ToInt();
value = tiff.GetField(TiffTag.TILEWIDTH);
int tileWidth = value[0].ToInt();
value = tiff.GetField(TiffTag.TILELENGTH);
int tileLength = value[0].ToInt();
byte[] buf = new byte[tiff.TileSize()];
for (int y = 0; y < imageLength; y += tileLength)
{
for (int x = 0; x < imageWidth; x += tileWidth)
{
tiff.ReadTile(buf, 0, x, y, 0, 0);
for (int row = 0; row < tileLength; row++)
{
for (int col = 0; col < tileWidth; col++)
{
if (x + col >= imageWidth || y + row >= imageLength)
{
break;
}
if (geotiffdata.bits == 16)
{
altdata[y + row, x + col] =
(short)((buf[row * tileWidth * 2 + col * 2 + 1] << 8) +
buf[row * tileWidth * 2 + col * 2]);
}
else if (geotiffdata.bits == 32)
{
altdata[y + row, x + col] =
(float)BitConverter.ToSingle(buf,
row * tileWidth * 4 + col * 4);
}
}
}
}
}
}
else
{
byte[] scanline = new byte[tiff.ScanlineSize()];
for (int row = 0; row < geotiffdata.height; row++)
{
tiff.ReadScanline(scanline, row);
for (int col = 0; col < geotiffdata.width; col++)
{
if (geotiffdata.bits == 16)
{
altdata[row, col] =
(short)((scanline[col * 2 + 1] << 8) + scanline[col * 2]);
}
else if (geotiffdata.bits == 32)
{
altdata[row, col] = (float)BitConverter.ToSingle(scanline, col * 4);
}
}
}
}
}
cache[geotiffdata.FileName] = altdata;
}
finally
{
lock (cacheloading)
{
cacheloading.Remove(geotiffdata.FileName);
}
}
});
return(srtm.altresponce.Invalid);
}
// get answer
var xf = map(lat, geotiffdata.Area.Top, geotiffdata.Area.Bottom, 0, geotiffdata.height - 1);
var yf = map(lng, geotiffdata.Area.Left, geotiffdata.Area.Right, 0, geotiffdata.width - 1);
int x_int = (int)xf;
double x_frac = xf - x_int;
int y_int = (int)yf;
double y_frac = yf - y_int;
// y_int = (geotiffdata.height - 2) - y_int;
double alt00 = GetAlt(geotiffdata, x_int, y_int);
double alt10 = GetAlt(geotiffdata, x_int + 1, y_int);
double alt01 = GetAlt(geotiffdata, x_int, y_int + 1);
double alt11 = GetAlt(geotiffdata, x_int + 1, y_int + 1);
double v1 = avg(alt00, alt10, x_frac);
double v2 = avg(alt01, alt11, x_frac);
double v = avg(v1, v2, y_frac);
if (v > -1000)
{
answer.currenttype = srtm.tiletype.valid;
}
if (alt00 < -1000 || alt10 < -1000 || alt01 < -1000 || alt11 < -1000)
{
answer.currenttype = srtm.tiletype.invalid;
}
answer.alt = v;
answer.altsource = "GeoTiff";
return(answer);
}
}
return(srtm.altresponce.Invalid);
}
public static srtm.altresponce getAltitude(double lat, double lng, double zoom = 16)
{
if (index.Count == 0)
{
return(srtm.altresponce.Invalid);
}
var answer = new srtm.altresponce();
foreach (var DTEDdata in index)
{
if (DTEDdata.Area.Contains(lat, lng))
{
// add to cache
if (!cache.ContainsKey(DTEDdata.FileName))
{
short[,] altdata = new short[DTEDdata.width, DTEDdata.height];
using (var stream = File.OpenRead(DTEDdata.FileName))
{
stream.Seek(3428, SeekOrigin.Begin);
for (int b = 0; b < (DTEDdata.height); b++)
{
var buffer = new byte[DTEDdata.height * 2 + 12]; // header + checksum + data(shorts)
stream.Read(buffer, 0, buffer.Length);
if (buffer[0] == 0xaa)
{
int blockno = ((int)buffer[1] << 16) + ((int)buffer[2] << 8) + buffer[3];
int longcount = ((int)buffer[4] << 8) + buffer[5];
int latcount = ((int)buffer[6] << 8) + buffer[7];
for (int a = 0; a < DTEDdata.width; a++)
{
altdata[longcount, latcount + a] =
(short)(((int)buffer[8 + a * 2] << 8) + buffer[8 + a * 2 + 1]);
}
}
}
}
cache[DTEDdata.FileName] = altdata;
}
// get answer
var xf = map(lng, DTEDdata.Area.Left, DTEDdata.Area.Right - DTEDdata.xscale, 0, DTEDdata.width - 1);
var yf = map(lat, DTEDdata.Area.Bottom, DTEDdata.Area.Top - DTEDdata.yscale, 0, DTEDdata.height - 1);
int x_int = (int)xf;
double x_frac = xf - x_int;
int y_int = (int)yf;
double y_frac = yf - y_int;
double alt00 = GetAlt(DTEDdata.FileName, x_int, y_int);
double alt10 = GetAlt(DTEDdata.FileName, x_int + 1, y_int);
double alt01 = GetAlt(DTEDdata.FileName, x_int, y_int + 1);
double alt11 = GetAlt(DTEDdata.FileName, x_int + 1, y_int + 1);
double v1 = avg(alt00, alt10, x_frac);
double v2 = avg(alt01, alt11, x_frac);
double v = avg(v1, v2, y_frac);
if (v > -1000)
{
answer.currenttype = srtm.tiletype.valid;
}
answer.alt = v;
answer.altsource = "DTED";
return(answer);
}
}
return(srtm.altresponce.Invalid);
}
