/// <summary>
/// Calculates the ViewPortTransfrom for the Current Heading and ViewPortCenter.
/// Invalidates the ViewPort to schedule a redraw.
/// </summary>
protected virtual void UpdateViewPortTransform()
{
if (ViewPortTransform == null)
{
return;
}
double scaleFactor = ViewPortProjection.GetZoomFactor(ZoomLevel);
double w2 = ActualWidth / 2d;
double h2 = ActualHeight / 2d;
MatrixDouble vpCenterTranslation = MatrixDouble.CreateTranslation(w2, h2);
MatrixDouble scale = MatrixDouble.CreateScale(scaleFactor);
MatrixDouble mapCenterTranslation = MatrixDouble.CreateTranslation(-ViewPortCenter.X, -ViewPortCenter.Y);
double heading = Heading * Math.PI / 180.0;
Point center = new Point(ViewPortCenter.X, ViewPortCenter.Y);
MatrixDouble mapRotation = MatrixDouble.CreateRotation(heading, center);
MatrixDouble objectRotation = MatrixDouble.CreateRotation(heading);
ViewPortTransform.Matrix = (mapRotation * mapCenterTranslation * scale * vpCenterTranslation).ToXamlMatrix();
ScaleRotateTransform.Matrix = (objectRotation * scale).ToXamlMatrix();
ScaleTransform.Matrix = scale.ToXamlMatrix();
RotateTransform.Matrix = objectRotation.ToXamlMatrix();
TranslationTransform.Matrix = (mapCenterTranslation * vpCenterTranslation).ToXamlMatrix();
InvalidateArrange();
OnViewPortChangedEvent();
}
protected virtual void OnMapCenterChanged(ILocation newCenter)
{
MapCenterChangedEvent?.Invoke(this, newCenter);
if (ViewPortProjection != null)
{
_viewPortCenter = ViewPortProjection.ToCartesian(MapCenter);
UpdateViewPortTransform();
}
}
public CartesianPoint GetCartesianFromPoint(Point point)
{
double zoomFactor = 1 / ViewPortProjection.GetZoomFactor(ZoomLevel);
double x = (point.X - RenderSize.Width / 2d) * zoomFactor + ViewPortCenter.X;
double y = (point.Y - RenderSize.Height / 2d) * zoomFactor + ViewPortCenter.Y;
MatrixDouble reverseRotationMatrix = MatrixDouble.CreateRotation(-TransformHelper.DegToRad(Heading), ViewPortCenter.ToPoint());
return(new CartesianPoint(reverseRotationMatrix.Transform(new Point(x, y))));
}
/// <summary>
/// This Method can be use to convert a Point on the Map to a Location (in the current Projection).
/// </summary>
/// <param name="point">A Position on the MapControl (such as the MousePointer)</param>
/// <returns>The location in the current Projection.</returns>
public ILocation GetLocationFromPoint(Point point)
{
try
{
Point cartesianLocation = ViewPortTransform.Inverse.TransformPoint(point);
ILocation position = ViewPortProjection.ToLocation(new CartesianPoint(cartesianLocation));
return(position);
}
catch (COMException)
{
//Inverse Matrix does not exist...
return(new Wgs84Location());
}
}
/// <summary>
/// This function calculates the smallest axis-aligned bounding box possible for the current ViewPort.
/// This means that if the current Map has a Heading that is not a multiple of 90°
/// this function will a bounding box that is bigger than the actual ViewPort.
/// </summary>
public virtual Rect GetViewportBounds()
{
double zoomFactor = ViewPortProjection.GetZoomFactor(ZoomLevel);
double halfHeight = RenderSize.Height / (2 * zoomFactor);
double halfWidth = RenderSize.Width / (2 * zoomFactor);
Point topLeft = new Point(ViewPortCenter.X - halfWidth, ViewPortCenter.Y - halfHeight);
Point bottomRight = new Point(ViewPortCenter.X + halfWidth, ViewPortCenter.Y + halfHeight);
RotateTransform rotation = new RotateTransform {
Angle = Heading, CenterY = ViewPortCenter.Y, CenterX = ViewPortCenter.X
};
Rect rect = new Rect(topLeft, bottomRight);
rect = rotation.TransformBounds(rect);
return(rect);
}
