public void CanConvertLatLngToPixel(double latDegrees, double lngDegrees, float xExpected, float yExpected)
{
var pixelPoint = TileServiceUtils.LatLngToPixel(latDegrees.LatDegreesToRadians(), lngDegrees.LonDegreesToRadians(), 32768);
Assert.Equal(xExpected, pixelPoint.x, 0);
Assert.Equal(yExpected, pixelPoint.y, 0);
}
private void TryZoomIn(MapParameters parameters, out int requiredWidth, out int requiredHeight, out Point pixelMin, out Point pixelMax)
{
pixelMin = TileServiceUtils.LatLngToPixel(parameters.bbox.minLat, parameters.bbox.minLng, parameters.numTiles);
pixelMax = TileServiceUtils.LatLngToPixel(parameters.bbox.maxLat, parameters.bbox.maxLng, parameters.numTiles);
requiredWidth = (int)Math.Abs(pixelMax.x - pixelMin.x);
requiredHeight = (int)Math.Abs(pixelMax.y - pixelMin.y);
//See if we can zoom in - occurs when the requested tile size is much larger than the bbox
var zoomedWidth = requiredWidth;
var zoomedHeight = requiredHeight;
int zoomLevel = parameters.zoomLevel;
Point zoomedPixelMin = pixelMin;
Point zoomedPixelMax = pixelMax;
long numTiles = parameters.numTiles;
//allow a 15% margin extra otherwise if the tile is only a few pixels bigger than the calculated zoom
//we use the smaller zoom level and end up with lots of space around the data.
//AdjustBoundingBoxToFit handles the bigger size.
var mapWidth = parameters.mapWidth * 1.15;
var mapHeight = parameters.mapHeight * 1.15;
while (zoomedWidth < mapWidth && zoomedHeight < mapHeight && zoomLevel < MAX_ZOOM_LEVEL)
{
parameters.zoomLevel = zoomLevel;
parameters.numTiles = numTiles;
requiredWidth = zoomedWidth;
requiredHeight = zoomedHeight;
pixelMin = zoomedPixelMin;
pixelMax = zoomedPixelMax;
zoomLevel++;
numTiles = TileServiceUtils.NumberOfTiles(zoomLevel);
zoomedPixelMin = TileServiceUtils.LatLngToPixel(parameters.bbox.minLat, parameters.bbox.minLng, numTiles);
zoomedPixelMax = TileServiceUtils.LatLngToPixel(parameters.bbox.maxLat, parameters.bbox.maxLng, numTiles);
zoomedWidth = (int)Math.Abs(zoomedPixelMax.x - zoomedPixelMin.x);
zoomedHeight = (int)Math.Abs(zoomedPixelMax.y - zoomedPixelMin.y);
}
}
/// <summary>
/// Get the map parameters for the report tile
/// </summary>
public MapParameters GetMapParameters(string bbox, int width, int height, bool addMargin, bool adjustBoundingBox)
{
log.LogDebug($"GetMapParameters: bbox={bbox}, width={width}, height={height}, addMargin={addMargin}, adjustBoundingBox={adjustBoundingBox}");
var bboxRadians = boundingBoxHelper.GetBoundingBox(bbox);
MapBoundingBox mapBox = new MapBoundingBox
{
minLat = bboxRadians.BottomLeftLat,
minLng = bboxRadians.BottomLeftLon,
maxLat = bboxRadians.TopRightLat,
maxLng = bboxRadians.TopRightLon
};
int zoomLevel = TileServiceUtils.CalculateZoomLevel(mapBox.maxLat - mapBox.minLat, mapBox.maxLng - mapBox.minLng);
long numTiles = TileServiceUtils.NumberOfTiles(zoomLevel);
MapParameters parameters = new MapParameters
{
bbox = mapBox,
zoomLevel = zoomLevel,
numTiles = numTiles,
mapWidth = width,
mapHeight = height,
addMargin = addMargin
};
if (adjustBoundingBox)
{
boundingBoxService.AdjustBoundingBoxToFit(parameters);
}
parameters.pixelTopLeft = TileServiceUtils.LatLngToPixel(mapBox.maxLat, mapBox.minLng, parameters.numTiles);
log.LogDebug("MapParameters: " + JsonConvert.SerializeObject(parameters));
return(parameters);
}
/// <summary>
/// Joins standard size DXF tiles together to form one large tile for the report
/// </summary>
private async Task <byte[]> JoinDxfTiles(MapParameters parameters, FileData dxfFile)
{
log.LogDebug($"JoinDxfTiles: {dxfFile.ImportedFileUid}, {dxfFile.Name}");
//Find the tiles that the bounding box fits into.
MasterDataModels.Point tileTopLeft = MasterDataModels.WebMercatorProjection.PixelToTile(parameters.pixelTopLeft);
MasterDataModels.Point pixelBottomRight = TileServiceUtils.LatLngToPixel(
parameters.bbox.minLat, parameters.bbox.maxLng, parameters.numTiles);
MasterDataModels.Point tileBottomRight = MasterDataModels.WebMercatorProjection.PixelToTile(pixelBottomRight);
int xnumTiles = (int)(tileBottomRight.x - tileTopLeft.x) + 1;
int ynumTiles = (int)(tileBottomRight.y - tileTopLeft.y) + 1;
int width = xnumTiles * MasterDataModels.WebMercatorProjection.TILE_SIZE;
int height = ynumTiles * MasterDataModels.WebMercatorProjection.TILE_SIZE;
using (Image <Rgba32> tileBitmap = new Image <Rgba32>(width, height))
{
//Find the offset of the bounding box top left point inside the top left tile
var point = new MasterDataModels.Point
{
x = tileTopLeft.x * MasterDataModels.WebMercatorProjection.TILE_SIZE,
y = tileTopLeft.y * MasterDataModels.WebMercatorProjection.TILE_SIZE
};
//Clip to the actual bounding box within the tiles.
int clipWidth = parameters.mapWidth;
int clipHeight = parameters.mapHeight;
int xClipTopLeft = (int)(parameters.pixelTopLeft.x - point.x);
int yClipTopLeft = (int)(parameters.pixelTopLeft.y - point.y);
//Unlike System.Drawing, which allows the clipRect to have negative x, y and which moves as well as clips when used with DrawImage
//as the source rectangle, ImageSharp does not respect negative values. So we will have to do extra work in this situation.
if (xClipTopLeft < 0)
{
clipWidth += xClipTopLeft;
xClipTopLeft = 0;
}
if (yClipTopLeft < 0)
{
clipHeight += yClipTopLeft;
yClipTopLeft = 0;
}
var clipRect = new Rectangle(xClipTopLeft, yClipTopLeft, clipWidth, clipHeight);
//Join all the DXF tiles into one large tile
await JoinDataOceanTiles(dxfFile, tileTopLeft, tileBottomRight, tileBitmap, parameters.zoomLevel);
//Now clip the large tile
tileBitmap.Mutate(ctx => ctx.Crop(clipRect));
if (clipWidth >= parameters.mapWidth && clipHeight >= parameters.mapHeight)
{
return(tileBitmap.BitmapToByteArray());
}
//and resize it if required tile area was overlapping rather than within the large tile
//(negative clip values above)
using (Image <Rgba32> resizedBitmap = new Image <Rgba32>(parameters.mapWidth, parameters.mapHeight))
{
Point offset = new Point(parameters.mapWidth - clipWidth, parameters.mapHeight - clipHeight);
resizedBitmap.Mutate(ctx => ctx.DrawImage(tileBitmap, PixelBlenderMode.Normal, 1f, offset));
return(resizedBitmap.BitmapToByteArray());
}
}
}