private void DrawWaterMark(ImageCreationContext context)
{
if (context.Width < 200)
{
// too small...
return;
}
var text = "IsraelHikingMap.osm.org.il";
var initialFontSize = 16;
var fontFamiliyName = "Arial";
using (Graphics graphics = Graphics.FromImage(context.Image))
using (var fill = new SolidBrush(Color.FromArgb(128, 0, 0, 0)))
using (var outline = new Pen(Color.FromArgb(128, 255, 255, 255), 6))
{
Font stringFont = new Font(fontFamiliyName, initialFontSize);
var stringSize = graphics.MeasureString(text, stringFont);
var ratio = (context.Width - 4) / stringSize.Width;
var bottomPosition = context.Height - 2 - stringSize.Height * ratio;
var fontSize = initialFontSize * ratio;
stringFont = new Font(fontFamiliyName, fontSize);
// Draw string to screen.
GraphicsPath path = new GraphicsPath();
path.AddString(text,
new FontFamily(fontFamiliyName),
(int)FontStyle.Regular,
graphics.DpiY * fontSize / 72, // em size,
new PointF(2, bottomPosition),
new StringFormat());
graphics.DrawPath(outline, path);
graphics.FillPath(fill, path);
}
}
/// <summary>
/// Allows conversion between the image pixels and wgs84 coordinates
/// </summary>
/// <param name="latLng"></param>
/// <param name="context"></param>
/// <returns></returns>
private PointF ConvertLatLngToPoint(LatLng latLng, ImageCreationContext context)
{
var x = (float)((GetXTile(latLng.Lng, context.N) - context.TopLeft.X) * TILE_SIZE);
var y = (float)((GetYTile(latLng.Lat, context.N) - context.TopLeft.Y) * TILE_SIZE);
return(new PointF(x, y));
}
/// <summary>
/// Will create a single image from all the tiles - this image will include the required image inside
/// </summary>
/// <param name="context"></param>
/// <returns></returns>
private async Task <Image> CreateSingleImageFromTiles(ImageCreationContext context)
{
var horizontalTiles = context.BottomRight.X - context.TopLeft.X + 1;
var verticalTiles = context.BottomRight.Y - context.TopLeft.Y + 1;
var tasks = new List <Task <ImageWithOffset> >();
foreach (var addressTemplate in context.AddressesTemplates)
{
for (int x = 0; x < horizontalTiles; x++)
{
for (int y = 0; y < verticalTiles; y++)
{
var task = GetTileImage(context.TopLeft, new Point(x, y), context.Zoom, addressTemplate);
tasks.Add(task);
}
}
}
var imagesWithOffsets = await Task.WhenAll(tasks);
var image = new Image <Rgba32>(horizontalTiles * TILE_SIZE, verticalTiles * TILE_SIZE);
foreach (var imageWithOffset in imagesWithOffsets)
{
image.Mutate(x => x.DrawImage(imageWithOffset.Image,
new Point(imageWithOffset.Offset.X * TILE_SIZE, imageWithOffset.Offset.Y * TILE_SIZE),
1.0f));
}
return(image);
}
/// <summary>
/// This will update the address templates and remove empty addresses
/// </summary>
/// <param name="context"></param>
private void UpdateAddressesTemplates(ImageCreationContext context)
{
var address = IsValidAddress(context.DataContainer.BaseLayer.Address)
? context.DataContainer.BaseLayer.Address
: GetBaseAddressFromInvalidString(context.DataContainer.BaseLayer.Address);
var addressTemplates = new List <AddressAndOpacity>
{
new AddressAndOpacity {
Address = FixAdrressTemplate(address), Opacity = context.DataContainer.BaseLayer.Opacity ?? 1.0
}
};
foreach (var layerData in context.DataContainer.Overlays ?? new List <LayerData>())
{
if (IsValidAddress(layerData.Address) == false)
{
continue;
}
var addressAndOpacity = new AddressAndOpacity
{
Address = FixAdrressTemplate(layerData.Address),
Opacity = layerData.Opacity ?? 1.0
};
addressTemplates.Add(addressAndOpacity);
}
context.AddressesTemplates = addressTemplates.ToArray();
}
/// <summary>
/// Will create a single image from all the tiles - this image will include the required image inside
/// </summary>
/// <param name="context"></param>
/// <returns></returns>
private async Task <Image> CreateSingleImageFromTiles(ImageCreationContext context)
{
var horizontalTiles = context.BottomRight.X - context.TopLeft.X + 1;
var verticalTiles = context.BottomRight.Y - context.TopLeft.Y + 1;
var bitmap = new Bitmap(horizontalTiles * TILE_SIZE, verticalTiles * TILE_SIZE);
var tasks = new List <Task <ImageWithOffset> >();
foreach (var addressTemplate in context.AddressesTemplates)
{
for (int x = 0; x < horizontalTiles; x++)
{
for (int y = 0; y < verticalTiles; y++)
{
var task = GetTileImage(context.TopLeft, new Point(x, y), context.Zoom, addressTemplate);
tasks.Add(task);
}
}
}
var imagesWithOffsets = await Task.WhenAll(tasks);
using (var graphics = Graphics.FromImage(bitmap))
{
foreach (var imageWithOffset in imagesWithOffsets)
{
graphics.DrawImage(imageWithOffset.Image,
new Rectangle(imageWithOffset.Offset.X * TILE_SIZE, imageWithOffset.Offset.Y * TILE_SIZE, TILE_SIZE, TILE_SIZE),
new Rectangle(0, 0, imageWithOffset.Image.Width, imageWithOffset.Image.Height),
GraphicsUnit.Pixel);
}
}
return(bitmap);
}
/// <summary>
/// This will update the address templates and remove empty addresses
/// </summary>
/// <param name="context"></param>
private void UpdateAddressesTemplates(ImageCreationContext context)
{
var address = IsValidAddress(context.DataContainer.BaseLayer.Address) == false
? "https://israelhiking.osm.org.il/Hebrew/tiles/{z}/{x}/{y}.png"
: context.DataContainer.BaseLayer.Address;
var addressTemplates = new List <AddressAndOpacity>
{
new AddressAndOpacity {
Address = FixAdrressTemplate(address), Opacity = context.DataContainer.BaseLayer.Opacity ?? 1.0
}
};
foreach (var layerData in context.DataContainer.Overlays ?? new List <LayerData>())
{
if (IsValidAddress(layerData.Address) == false)
{
continue;
}
var addressAndOpacity = new AddressAndOpacity
{
Address = FixAdrressTemplate(layerData.Address),
Opacity = layerData.Opacity ?? 1.0
};
addressTemplates.Add(addressAndOpacity);
}
context.AddressesTemplates = addressTemplates.ToArray();
}
/// <summary>
/// This will update the backgroud image - which is the image created from the baselayer and the overlay tiles
/// </summary>
/// <param name="context"></param>
/// <returns></returns>
private async Task UpdateBackGroundImage(ImageCreationContext context)
{
var topLeft = new Point((int)GetXTile(context.DataContainer.SouthWest.Lng, context.N), (int)GetYTile(context.DataContainer.NorthEast.Lat, context.N));
var bottomRight = new Point((int)GetXTile(context.DataContainer.NorthEast.Lng, context.N), (int)GetYTile(context.DataContainer.SouthWest.Lat, context.N));
context.TopLeft = topLeft;
context.BottomRight = bottomRight;
context.Image = await CreateSingleImageFromTiles(context);
}
/// <summary>
/// Crop and resizes the image to the desired dimentions
/// </summary>
/// <param name="context"></param>
private void CropAndResizeImage(ImageCreationContext context)
{
var topLeft = ConvertLatLngToPoint(context.DataContainer.SouthWest, context);
var bottomRight = ConvertLatLngToPoint(context.DataContainer.NorthEast, context);
context.Image.Mutate(x =>
x.Crop(new Rectangle((int)topLeft.X, (int)bottomRight.Y, (int)(bottomRight.X - topLeft.X), (int)(topLeft.Y - bottomRight.Y)))
.Resize(context.Width, context.Height)
);
}
/// <summary>
/// Crop and resizes the image to the desired dimentions
/// </summary>
/// <param name="context"></param>
private void CropAndResizeImage(ImageCreationContext context)
{
Bitmap bmp = new Bitmap(context.Width, context.Height);
using (Graphics graphics = Graphics.FromImage(bmp))
{
var topLeft = ConvertLatLngToPoint(context.DataContainer.SouthWest, context);
var bottomRight = ConvertLatLngToPoint(context.DataContainer.NorthEast, context);
graphics.DrawImage(context.Image, new Rectangle(0, 0, bmp.Width, bmp.Height), topLeft.X, bottomRight.Y, bottomRight.X - topLeft.X, topLeft.Y - bottomRight.Y, GraphicsUnit.Pixel);
}
context.Image = bmp;
}
/// <summary>
/// This will draw on the backgroup image the route and markers according to color and opacity
/// </summary>
/// <param name="context"></param>
private void DrawRoutesOnImage(ImageCreationContext context)
{
var penWidth = PEN_WIDTH;
var penWidthOffset = 8;
var circleOutlineWidth = 7f;
var circleSize = CIRCLE_SIZE;
using (var graphics = Graphics.FromImage(context.Image))
using (var outLinerPen = new Pen(Color.White, penWidth + penWidthOffset)
{
LineJoin = LineJoin.Bevel
})
using (var circleFillBrush = new SolidBrush(Color.White))
using (var startRoutePen = new Pen(Color.Green, circleOutlineWidth))
using (var endRoutePen = new Pen(Color.Red, circleOutlineWidth))
{
var routeColorIndex = 0;
foreach (var route in context.DataContainer.Routes)
{
var points = route.Segments.SelectMany(s => s.Latlngs).Select(l => ConvertLatLngToPoint(l, context)).ToArray();
var markerPoints = route.Markers.Select(m => ConvertLatLngToPoint(m.Latlng, context));
var lineColor = _routeColors[routeColorIndex++];
routeColorIndex = routeColorIndex % _routeColors.Length;
if (!string.IsNullOrEmpty(route.Color))
{
lineColor = FromColorString(route.Color, route.Opacity);
}
using (var linePen = new Pen(lineColor, penWidth)
{
LineJoin = LineJoin.Bevel
})
{
if (points.Any())
{
graphics.DrawLines(outLinerPen, points);
graphics.DrawLines(linePen, points);
graphics.FillEllipse(circleFillBrush, points.First().X - circleSize / 2, points.First().Y - circleSize / 2, circleSize, circleSize);
graphics.DrawEllipse(startRoutePen, points.First().X - circleSize / 2, points.First().Y - circleSize / 2, circleSize, circleSize);
graphics.FillEllipse(circleFillBrush, points.Last().X - circleSize / 2, points.Last().Y - circleSize / 2, circleSize, circleSize);
graphics.DrawEllipse(endRoutePen, points.Last().X - circleSize / 2, points.Last().Y - circleSize / 2, circleSize, circleSize);
}
foreach (var markerPoint in markerPoints)
{
graphics.FillEllipse(circleFillBrush, markerPoint.X - circleSize / 2, markerPoint.Y - circleSize / 2, circleSize, circleSize);
graphics.DrawEllipse(linePen, markerPoint.X - circleSize / 2, markerPoint.Y - circleSize / 2, circleSize, circleSize);
}
}
}
}
}
/// <summary>
/// Updates the zoom that will have tiles that have more pixels than the image needs
/// This will make sure the image size will be bigger than the desired image to improve quility
/// </summary>
/// <param name="context"></param>
private void UpdateZoom(ImageCreationContext context)
{
var zoom = 0;
double n;
double deltaX;
double deltaY;
do
{
zoom++;
n = Math.Pow(2, zoom);
deltaX = GetXTile(context.DataContainer.NorthEast.Lng, n) - GetXTile(context.DataContainer.SouthWest.Lng, n);
deltaY = GetYTile(context.DataContainer.SouthWest.Lat, n) - GetYTile(context.DataContainer.NorthEast.Lat, n);
deltaX *= TILE_SIZE;
deltaY *= TILE_SIZE;
} while (deltaX < context.Width && deltaY < context.Height);
context.Zoom = zoom;
context.N = n;
}
/// <summary>
/// Updates the conrners of the datacontainer to fix the relevant image ratio
/// It will increase the height or width of the container as needed.
/// </summary>
/// <param name="context"></param>
private void UpdateCorners(ImageCreationContext context)
{
if (context.DataContainer.NorthEast == null || context.DataContainer.SouthWest == null)
{
var allLocations = context.DataContainer.Routes
.SelectMany(r => r.Segments)
.SelectMany(s => s.Latlngs)
.Concat(context.DataContainer.Routes
.SelectMany(r => r.Markers)
.Select(m => m.Latlng)
)
.ToArray();
context.DataContainer.NorthEast = new LatLng(allLocations.Max(l => l.Lat), allLocations.Max(l => l.Lng));
context.DataContainer.SouthWest = new LatLng(allLocations.Min(l => l.Lat), allLocations.Min(l => l.Lng));
}
var n = Math.Pow(2, MAX_ZOOM);
var xNorthEast = GetXTile(context.DataContainer.NorthEast.Lng, n);
var yNorthEast = GetYTile(context.DataContainer.NorthEast.Lat, n);
var xSouthWest = GetXTile(context.DataContainer.SouthWest.Lng, n);
var ySouthWest = GetYTile(context.DataContainer.SouthWest.Lat, n);
var ratio = context.Width * 1.0 / context.Height;
if (xNorthEast - xSouthWest > ratio * (ySouthWest - yNorthEast))
{
var desiredY = (xNorthEast - xSouthWest) / ratio;
var delatY = (desiredY - (ySouthWest - yNorthEast)) / 2;
ySouthWest += delatY;
yNorthEast -= delatY;
}
else
{
var desiredX = (ySouthWest - yNorthEast) * ratio;
var delatX = (desiredX - (xNorthEast - xSouthWest)) / 2;
xNorthEast += delatX;
xSouthWest -= delatX;
}
context.DataContainer.NorthEast.Lng = GetLongitude(xNorthEast, n);
context.DataContainer.NorthEast.Lat = GetLatitude(yNorthEast, n);
context.DataContainer.SouthWest.Lng = GetLongitude(xSouthWest, n);
context.DataContainer.SouthWest.Lat = GetLatitude(ySouthWest, n);
}
///<inheritdoc />
public async Task <byte[]> Create(DataContainer dataContainer, int width, int height)
{
var context = new ImageCreationContext
{
Width = width,
Height = height,
DataContainer = dataContainer
};
UpdateCorners(context);
UpdateZoom(context);
UpdateAddressesTemplates(context);
await UpdateBackGroundImage(context);
DrawRoutesOnImage(context);
CropAndResizeImage(context);
var imageStream = new MemoryStream();
context.Image.SaveAsPng(imageStream);
return(imageStream.ToArray());
}
/// <summary>
/// This will draw on the backgroup image the route and markers according to color and opacity
/// </summary>
/// <param name="context"></param>
private void DrawRoutesOnImage(ImageCreationContext context)
{
context.Image.Mutate(ctx =>
{
var routeColorIndex = 0;
foreach (var route in context.DataContainer.Routes)
{
var points = route.Segments.SelectMany(s => s.Latlngs).Select(l => ConvertLatLngToPoint(l, context)).ToArray();
var markerPoints = route.Markers.Select(m => ConvertLatLngToPoint(m.Latlng, context));
var lineColor = _routeColors[routeColorIndex++];
routeColorIndex = routeColorIndex % _routeColors.Length;
if (!string.IsNullOrEmpty(route.Color))
{
lineColor = FromColorString(route.Color, route.Opacity);
}
if (points.Any())
{
var path = new SixLabors.Shapes.Path(new LinearLineSegment(points));
ctx.Draw(Color.White, PEN_WIDTH + PEN_WIDTH_OFFSET, path);
ctx.Draw(lineColor, PEN_WIDTH, path);
var startCircle = new EllipsePolygon(points.First(), CIRCLE_RADIUS);
ctx.Fill(Color.White, startCircle);
ctx.Draw(Color.Green, CIRCLE_OUTLINE_WIDTH, startCircle);
var endCircle = new EllipsePolygon(points.Last(), CIRCLE_RADIUS);
ctx.Fill(Color.White, endCircle);
ctx.Draw(Color.Red, CIRCLE_OUTLINE_WIDTH, endCircle);
}
foreach (var markerPoint in markerPoints)
{
var markerEllipse = new EllipsePolygon(markerPoint, CIRCLE_RADIUS);
ctx.Fill(Color.White, markerEllipse);
ctx.Draw(lineColor, PEN_WIDTH, markerEllipse);
}
}
});
}
///<inheritdoc />
public async Task <byte[]> Create(DataContainer dataContainer, int width, int height)
{
_logger.LogDebug("Creating image for thumbnail started.");
var context = new ImageCreationContext
{
Width = width,
Height = height,
DataContainer = dataContainer
};
UpdateCorners(context);
UpdateZoom(context);
UpdateAddressesTemplates(context);
await UpdateBackGroundImage(context);
DrawRoutesOnImage(context);
CropAndResizeImage(context);
var imageStream = new MemoryStream();
context.Image.Save(imageStream, ImageFormat.Png);
_logger.LogDebug("Creating image for thumbnail completed.");
return(imageStream.ToArray());
}
