private ImageSource GetImage(MapProjection projection, IEnumerable <IMapDrawingItem> items)
{
var scale = ParentMap.ViewTransform.Scale;
var rotation = ParentMap.ViewTransform.Rotation;
var mapRect = projection.BoundingBoxToRect(BoundingBox);
var imageRect = new Rect(0, 0, scale * mapRect.Width, scale * mapRect.Height);
var drawings = new DrawingGroup();
foreach (var item in items)
{
var positions = item.Locations.Select(l => projection.LocationToMap(l)).ToList();
if (positions.Any(p => mapRect.Contains(p)))
{
for (int i = 0; i < positions.Count; i++)
{
positions[i] = new Point(scale * (positions[i].X - mapRect.X),
imageRect.Height - scale * (positions[i].Y - mapRect.Y));
}
drawings.Children.Add(item.GetDrawing(positions, scale, rotation));
}
}
var drawingBrush = new DrawingBrush
{
Drawing = drawings,
ViewboxUnits = BrushMappingMode.Absolute,
Viewbox = imageRect,
};
var drawing = new GeometryDrawing
{
Geometry = new RectangleGeometry(imageRect),
Brush = drawingBrush
};
var image = new DrawingImage(drawing);
image.Freeze();
return(image);
}
/// <summary>
/// Transforms a Location in geographic coordinates to a Point in view coordinates.
/// </summary>
public Point LocationToView(Location location)
{
return(ViewTransform.MapToView(MapProjection.LocationToMap(location)));
}
