public byte[] GenerateTile(int x, int y, int zoom)
{
byte[] tileBytes = null;
var font = SixLabors.Fonts.SystemFonts.CreateFont("Arial", 12);
var corner = TileUtils.TileXYToGlobalPixel(x, y, TileSize);
var latLong = TileUtils.GlobalPixelToPosition(new Point <double>(corner.X, corner.Y), zoom, TileSize);
var latLongOffset = TileUtils.GlobalPixelToPosition(new Point <double>(corner.X + TileSize, corner.Y + TileSize), zoom, TileSize);
var graticules = graticuleService.DrawCore(latLong, latLongOffset);
using (Image <Rgba32> outputImage = new Image <Rgba32>(this.TileSize, this.TileSize))
{
string tileText = $"{x}/{y}/{zoom}{Environment.NewLine}";
outputImage.Mutate(o => o
.Fill(Rgba32.White)
.DrawText(tileText, font, Rgba32.Black, new PointF(10, 10))
);
outputImage.Mutate(o => DrawGraticules(o, graticules, corner, zoom));
// Test
if (DebugPoint != null)
{
var testPixel = TileUtils.PositionToGlobalPixel(new LatLong(DebugPoint.Latitude, DebugPoint.Longitude), zoom, TileSize);
var testTile = TileUtils.GlobalPixelToTileXY(testPixel.X, testPixel.Y, TileSize);
// Draw test pixel
if (testTile.X == x && testTile.Y == y)
{
var basex = TileUtils.TileXYToGlobalPixel(x, y, TileSize);
var ptLoc = new PointF((float)(testPixel.X - basex.X), (float)(testPixel.Y - basex.Y));
outputImage.Mutate(o =>
o.DrawLines(Rgba32.Blue, 1f,
new PointF[] { new PointF(ptLoc.X - 10, ptLoc.Y - 10), new PointF(ptLoc.X + 10, ptLoc.Y + 10) })
.DrawLines(Rgba32.Blue, 1f,
new PointF[] { new PointF(ptLoc.X - 10, ptLoc.Y + 10), new PointF(ptLoc.X + 10, ptLoc.Y - 10) }));
}
}
using (MemoryStream ms = new MemoryStream())
{
outputImage.SaveAsPng(ms);
tileBytes = ms.ToArray();
}
}
return(tileBytes);
}
public TileRange ComputeBoundingBoxTileRangeForZoomLevel(BoundingBox bbox, ImageryProvider provider, int zoom)
{
TileRange tiles = new TileRange(provider);
Point <double> topLeft = TileUtils.PositionToGlobalPixel(new LatLong(bbox.yMax, bbox.xMin), zoom, provider.TileSize);
Point <double> bottomRight = TileUtils.PositionToGlobalPixel(new LatLong(bbox.yMin, bbox.xMax), zoom, provider.TileSize);
BoundingBox mapBbox = new BoundingBox(topLeft.X, bottomRight.X, topLeft.Y, bottomRight.Y);
tiles.Start = new MapTileInfo(TileUtils.GlobalPixelToTileXY(topLeft.X, topLeft.Y, provider.TileSize), zoom, provider.TileSize);
tiles.End = new MapTileInfo(TileUtils.GlobalPixelToTileXY(bottomRight.X, bottomRight.Y, provider.TileSize), zoom, provider.TileSize);
tiles.AreaOfInterest = mapBbox;
return(tiles);
}
public TileRange ComputeBoundingBoxTileRangeForTargetResolution(BoundingBox bbox, ImageryProvider imageryProvider, int width, int height)
{
TileRange tiles = new TileRange(imageryProvider);
TileUtils.BestMapView(new double[] { bbox.xMin, bbox.yMin, bbox.xMax, bbox.yMax }, width, height, 0, imageryProvider.TileSize, out double _, out double _, out double zoom);
zoom = Math.Round(zoom, 0);
var topLeft = TileUtils.PositionToGlobalPixel(new LatLong(bbox.yMax, bbox.xMin), (int)zoom, imageryProvider.TileSize);
var bottomRight = TileUtils.PositionToGlobalPixel(new LatLong(bbox.yMin, bbox.xMax), (int)zoom, imageryProvider.TileSize);
var mapBbox = new BoundingBox(topLeft.X, bottomRight.X, topLeft.Y, bottomRight.Y);
tiles.Start = new MapTileInfo(TileUtils.GlobalPixelToTileXY(topLeft.X, topLeft.Y, imageryProvider.TileSize), (int)zoom, imageryProvider.TileSize);
tiles.End = new MapTileInfo(TileUtils.GlobalPixelToTileXY(bottomRight.X, bottomRight.Y, imageryProvider.TileSize), (int)zoom, imageryProvider.TileSize);
tiles.AreaOfInterest = mapBbox;
return(tiles);
}
public TileRange ComputeBoundingBoxTileRange(BoundingBox bbox, ImageryProvider provider,
int minTilesPerImage = 4)
{
// TODO good one, to test
// texture quality would be expressed in tex size
//TileUtils.BestMapView(new double[] { bbox.xMin, bbox.yMin, bbox.xMax, bbox.yMax }, 16384, 16384, 0, provider.TileSize, out double centerLat, out double centerLon, out double zoomBestView);
TileRange tiles = new TileRange(provider);
BoundingBox mapBbox;
Point <double> topLeft;
Point <double> bottomRight;
// optimal zoom calculation (maybe there's a direct way)
// see : https://docs.microsoft.com/fr-fr/azure/azure-maps/zoom-levels-and-tile-grid?tabs=csharp#tile-math-source-code (prepare tissues for nose bleed, and don't go if you're allergic to trigo and/or magical constants)
// calculate the size of the full bbox at increasing zoom levels
// until the full image would be greater than a tile
int zoom = 0;
int maxSize = 256 * minTilesPerImage; /* fixed to 256px to limit number of tiles */
do
{
zoom++;
// coords are pixels in global map image (see TileUtils.MapSize(zoom))
topLeft = TileUtils.PositionToGlobalPixel(new LatLong(bbox.yMax, bbox.xMin), zoom, provider.TileSize);
bottomRight = TileUtils.PositionToGlobalPixel(new LatLong(bbox.yMin, bbox.xMax), zoom, provider.TileSize);
mapBbox = new BoundingBox(topLeft.X, bottomRight.X, topLeft.Y, bottomRight.Y);
} while (zoom < provider.MaxZoom &&
Math.Min(mapBbox.Width, mapBbox.Height) < maxSize);
// now we have the minimum zoom without image
// we can know which tiles are needed
tiles.Start = new MapTileInfo(TileUtils.GlobalPixelToTileXY(topLeft.X, topLeft.Y, provider.TileSize), zoom, provider.TileSize);
tiles.End = new MapTileInfo(TileUtils.GlobalPixelToTileXY(bottomRight.X, bottomRight.Y, provider.TileSize), zoom, provider.TileSize);
tiles.AreaOfInterest = mapBbox;
return(tiles);
}