public List <Vector2> ComputeUVMap(HeightMap heightMap, TextureInfo textureInfo)
{
/**********************************
* We need to map texture pixels to heightmap points
* Linear mapping does not work because or Mercator projection distortion
* Pseudo code :
* for each point
* project to texture coordinates (pixelXY at same zoom than texture)
* get pixel offset from origin
* map this offset to (0 -> texWidth, 0 -> textHeight) => (0->1, 0->1)
*/
List <Vector2> uvs = new List <Vector2>(heightMap.Count);
var bbox = textureInfo.ProjectedBounds;
foreach (GeoPoint geoPoint in heightMap.Coordinates)
{
PointInt projPoint = TileUtils.LatLongToPixelXY(geoPoint.Latitude, geoPoint.Longitude, textureInfo.ProjectedZoom);
float xOffset = projPoint.X - (float)bbox.xMin;
float uvX = MathHelper.Map(1, textureInfo.Width, 0, 1, xOffset, true);
float yOffset = projPoint.Y - (float)bbox.yMin;
float uvY = MathHelper.Map(1, textureInfo.Height, 0, 1, yOffset, true);
uvs.Add(new Vector2(uvX, uvY));
}
return(uvs);
}
public TileRange DownloadTiles(BoundingBox bbox, ImageryProvider provider, int minTilesPerImage = 4)
{
TileRange tiles = new TileRange(provider);
BoundingBox mapBbox = null;
PointInt topLeft = new PointInt();
PointInt bottomRight = new PointInt();
// optimal zoom calculation (maybe there's a direct way)
// calculate the size of the full bbox at increasing zoom levels
// until the full image would be greater than a tile
int zoom = 0;
do
{
zoom++;
// coords are pixels in global map image (see TileUtils.MapSize(zoom))
topLeft = TileUtils.LatLongToPixelXY(bbox.yMax, bbox.xMin, zoom);
bottomRight = TileUtils.LatLongToPixelXY(bbox.yMin, bbox.xMax, zoom);
mapBbox = new BoundingBox(topLeft.X, bottomRight.X, topLeft.Y, bottomRight.Y);
}while (zoom < provider.MaxZoom &&
(mapBbox.Width < provider.TileSize * minTilesPerImage && mapBbox.Height < provider.TileSize * minTilesPerImage));
// now we have the minimum zoom without image
// we can know which tiles are needed
tiles.Start = new MapTileInfo(TileUtils.PixelXYToTileXY(topLeft.X, topLeft.Y), zoom);
tiles.End = new MapTileInfo(TileUtils.PixelXYToTileXY(bottomRight.X, bottomRight.Y), zoom);
tiles.AreaOfInterest = mapBbox;
// downdload tiles
Stopwatch swDownload = Stopwatch.StartNew();
_logger?.LogTrace("Starting images download");
// 2 max download threads
var options = new ParallelOptions()
{
MaxDegreeOfParallelism = provider.MaxDegreeOfParallelism
};
var range = tiles.EnumerateRange().ToList();
_logger.LogInformation($"Downloading {range.Count} tiles...");
Parallel.ForEach(range, options, tileInfo =>
{
Uri tileUri = BuildUri(provider, tileInfo.X, tileInfo.Y, tileInfo.Zoom);
_logger?.LogInformation($"Downloading {tileUri}");
var contentbytes = _httpClient.GetByteArrayAsync(tileUri).Result;
tiles.Add(new MapTile(contentbytes, provider.TileSize, tileUri, tileInfo));
}
);
swDownload.Stop();
_logger?.LogInformation($"DownloadImages done in : {swDownload.Elapsed:g}");
return(tiles);
}
public GraticuleLabel(LatLong worldLocation)
{
this.label = null;
this.location = new PointInt(0, 0);
this.worldLocation = worldLocation;
}
public GraticuleLabel(string Label, PointInt Location)
{
this.label = Label;
this.location = Location;
this.worldLocation = new LatLong(0, 0);
}
public MapTileInfo(PointInt xy, int zoom)
{
X = xy.X;
Y = xy.Y;
Zoom = zoom;
}
private void DrawGraticules(IImageProcessingContext img, GraticuleLabels graticules, PointInt corner, int zoom)
{
var font = SixLabors.Fonts.SystemFonts.CreateFont("Arial", 8);
foreach (var meridian in graticules.VerticalLabels)
{
var loc = meridian.worldLocation;
var pt = TileUtils.LatLongToPixelXY(loc.Lat, loc.Long, zoom);
var xpos = pt.X - corner.X;
var start = new PointF(xpos, 0);
var end = new PointF(xpos, TileSize);
img.DrawLines(Rgba32.Gray, 1f, new PointF[] { start, end });
try
{
if (xpos < TileSize - 10)
{
img.DrawText(Math.Round(loc.Long, 2).ToString(), font, Rgba32.Black, new PointF(xpos, 50));
}
}
catch (Exception)
{
}
}
foreach (var parallel in graticules.HorizontalLabels)
{
var loc = parallel.worldLocation;
var pt = TileUtils.LatLongToPixelXY(loc.Lat, loc.Long, zoom);
var ypos = pt.Y - corner.Y;
var start = new PointF(0, ypos);
var end = new PointF(TileSize, ypos);
img.DrawLines(Rgba32.Gray, 1f, new PointF[] { start, end });
try
{
img.DrawText(Math.Round(loc.Lat, 4).ToString(), font, Rgba32.Black, new PointF(50, ypos));
}
catch (Exception)
{
}
}
}
