public async Task <RasterInfo> LoadMetadata(string path)
{
var info = await RasterInfo.CreateFromMapFileAsync(path);
if (!PotentialTiles.Contains(info))
{
PotentialTiles.Add(info);
}
return(info);
}
/// <summary>
/// Reads the metadata from a file. NOTE: this is a synchronous call.
/// </summary>
/// <param name="fullPath">the file to read the metadata from</param>
/// <returns>the RasterInfo for that file</returns>
public static RasterInfo CreateFromMapFile(string fullPath)
{
var rasterInfo = new RasterInfo(fullPath);
using (var dataset = Gdal.OpenShared(fullPath, Access.GA_ReadOnly))
{
rasterInfo.ImageSize = new Size(dataset.RasterXSize, dataset.RasterYSize);
rasterInfo.NumberOfBands = dataset.RasterCount;
rasterInfo.Projection = dataset.GetProjection();
rasterInfo.MapArea = CalculateMapArea(dataset);
}
Preprocessor pre = new Preprocessor();
foreach (int zoomLevel in Enumerable.Range(0, 5))
{
pre.ProjectAndTile(rasterInfo, zoomLevel, null);
}
return(rasterInfo);
}
public void ProjectAndTile(RasterInfo originFile, int zoomLevel, IProgress <Status> progress)
{
var status = new Status
{
Total = SupportedProjections.Length,
Current = 0
};
foreach (var projection in SupportedProjections)
{
Size fullMapSize = projection.FullMapSizeFor(zoomLevel);
var tilesWide = fullMapSize.Width / projection.TileSize.Width;
var tilesTall = fullMapSize.Height / projection.TileSize.Height;
status.Current++;
status.Total += tilesWide * tilesTall;
status.Message = $"Projecting {projection.Name} at Zoom Level {zoomLevel}";
progress?.Report(status);
string baseDir = Path.Combine(projection.GetType().Name, $"{zoomLevel}");
if (!Directory.Exists(baseDir))
{
Directory.CreateDirectory(baseDir);
}
using (var source = Gdal.OpenShared(originFile.FullPath, Access.GA_ReadOnly))
using (var destination = Gdal.AutoCreateWarpedVRT(source, source.GetProjection(), projection.Wkt,
ResampleAlg.GRA_NearestNeighbour, .0125))
{
var sourceInfo = DetermineRenderInformation(destination);
var ratioX = destination.RasterXSize / fullMapSize.Width;
var ratioY = destination.RasterYSize / fullMapSize.Height;
var destWidth = (int)projection.TileSize.Width;
var destHeight = (int)projection.TileSize.Height;
var sourceWidth = (int)(destWidth * ratioX);
var sourceHeight = (int)(destHeight * ratioY);
var buffer = new byte[destWidth * destHeight * sourceInfo.ChannelCount];
var stride = destWidth * sourceInfo.ChannelCount;
for (int row = 0; row < tilesWide; row++)
{
for (int column = 0; column < tilesTall; column++)
{
int x = column * sourceWidth;
int y = row * sourceHeight;
destination.ReadRaster(x, y, sourceWidth, sourceHeight, buffer, destWidth,
destHeight, sourceInfo.ChannelCount, sourceInfo.BandMap, sourceInfo.PixelSpace, stride, 1);
var bitmap = BitmapSource.Create(destWidth, destHeight, 96, 96, sourceInfo.PixelFormat,
sourceInfo.Colors, buffer, stride);
using (var stream = File.Create(Path.Combine(baseDir, $"{row}-{column}.png")))
{
var encoder = new PngBitmapEncoder();
encoder.Frames.Add(BitmapFrame.Create(bitmap));
encoder.Save(stream);
}
status.Current++;
progress?.Report(status);
}
}
}
}
status.Current = status.Total;
status.Message = string.Empty;
progress?.Report(status);
}
