private void AdjustFrameBufferMatrix(MapPosition mapPositionFrameBuffer, Dimension mapViewDimension, double scaleFactor, LatLong pivot)
{
MapPosition mapViewPosition = this.model.mapViewPosition.MapPosition;
long mapSize = MercatorProjection.GetMapSize(mapPositionFrameBuffer.ZoomLevel, model.displayModel.TileSize);
Point pointFrameBuffer = MercatorProjection.GetPixel(mapPositionFrameBuffer.LatLong, mapSize);
Point pointMapPosition = MercatorProjection.GetPixel(mapViewPosition.LatLong, mapSize);
double diffX = pointFrameBuffer.X - pointMapPosition.X;
double diffY = pointFrameBuffer.Y - pointMapPosition.Y;
// we need to compute the pivot distance from the map center
// as we will need to find the pivot point for the
// frame buffer (which generally has not the same size as the
// map view).
double pivotDistanceX = 0d;
double pivotDistanceY = 0d;
if (pivot != null)
{
Point pivotXY = MercatorProjection.GetPixel(pivot, mapSize);
pivotDistanceX = pivotXY.X - pointFrameBuffer.X;
pivotDistanceY = pivotXY.Y - pointFrameBuffer.Y;
}
float currentScaleFactor = (float)(scaleFactor / Math.Pow(2, mapPositionFrameBuffer.ZoomLevel));
this.frameBuffer.AdjustMatrix((float)diffX, (float)diffY, currentScaleFactor, mapViewDimension, (float)pivotDistanceX, (float)pivotDistanceY);
}
/// <summary>
/// The pivot point is the point the map zooms around. If the map zooms around its center null is returned, otherwise
/// the zoom-specific x/y pixel coordinates for the MercatorProjection (note: not the x/y coordinates for the map
/// view or the frame buffer, the MapViewPosition knows nothing about them).
/// </summary>
/// <param name="zoomLevel"> the zoomlevel to compute the x/y coordinates for </param>
/// <returns> the x/y coordinates of the map pivot point if set or null otherwise. </returns>
public virtual Point GetPivotXY(sbyte zoomLevel)
{
lock (this)
{
if (this.pivot != null)
{
return(MercatorProjection.GetPixel(this.pivot, MercatorProjection.GetMapSize(zoomLevel, displayModel.TileSize)));
}
return(null);
}
}