public static bool GetGeodesicSizePrecise(this IPrintableMap map, IEnvelope extents, out GeoSize size)
{
size = null;
double width, height;
if (map.Projection.HasTransformation)
{
// the projection supports coordinate tranformation to WGS84
if (CalculateExtentsWidth(map, extents, out width) &&
CalculateExtentsHeight(map, extents, out height))
{
size = new GeoSize(width, height);
return(true);
}
}
if (map.Projection.IsGeographic)
{
// it's WGS84
var center = extents.Center;
width = GeodesicDistance(center.Y, extents.MinX, center.Y, extents.MaxX);
height = GeodesicDistance(extents.MinY, center.X, extents.MaxY, center.X);
size = new GeoSize(width, height);
return(true);
}
return(false);
}
/// <summary>
/// Recursively calculates new extents of the map ot cover a certain geo size in meters.
/// </summary>
private static IEnvelope CalcNewExtentsCore(
IPrintableMap map,
IEnvelope oldExtents,
GeoSize newSize,
SizeF paperSize,
ref int depth)
{
depth++;
GeoSize oldSize;
if (map.GetGeodesicSize(oldExtents, out oldSize))
{
const int maxDepth = 5;
double newScale = CalcMapScale(newSize, paperSize);
double oldScale = CalcMapScale(oldSize, paperSize);
if (NumericHelper.Equal(newScale, oldScale, 1e-6) || depth > maxDepth)
{
return(oldExtents);
}
double ratio = newScale / oldScale - 1;
double dx = oldExtents.Width * ratio;
double dy = oldExtents.Height * ratio;
var extents = oldExtents.Inflate(dx, dy);
return(CalcNewExtentsCore(map, extents, newSize, paperSize, ref depth));
}
return(null);
}
private void Map1_Loaded(object sender, RoutedEventArgs e)
{
Map1.MapUnit = GeoUnit.Meter;
GeoImage image = new GeoImage(@"SampleData/bing-aerial-900913.png");
GeoSize size = image.GetSize();
GeoImageLayer geoImageLayer = new GeoImageLayer(image, new WorldFile(GeoCommonHelper.GetMaxBound(GeoUnit.Meter), (float)size.Width, (float)size.Height));
LayerOverlay layerOverlay = new LayerOverlay();
layerOverlay.Layers.Add(geoImageLayer);
Map1.Overlays.Add(layerOverlay);
Map1.ZoomToFullBound();
}
/// <summary>
/// Calculates the size of specified map extents in meters.
/// </summary>
public static bool GetGeodesicSize(this IPrintableMap map, IEnvelope extents, out GeoSize size)
{
bool result = GetGeodesicSizePrecise(map, extents, out size);
if (result)
{
return(true);
}
// we have nothing better but return width and height of the extents in original
// coordinate system; only let's convert them to meters (geodesic size is always in meters)
double width = UnitConversionHelper.Convert(map.MapUnits, LengthUnits.Meters, extents.Width);
double height = UnitConversionHelper.Convert(map.MapUnits, LengthUnits.Meters, extents.Height);
size = new GeoSize(width, height);
return(true);
}
/// <summary>
/// Calculates the size of the map on screen for a given size of map area and scale.
/// </summary>
/// <param name="mapScale">Map scale.</param>
/// <param name="geoSize">Geodesic size of the map area in meters.</param>
/// <param name="xyRatio">The X / Y ratio for the extents in original coordinate system.</param>
/// <returns>Size of the map on the screen in 1/100 of an inch.</returns>
public static SizeF CalcMapSize(int mapScale, GeoSize geoSize, double xyRatio)
{
double cf = LengthUnits.Meters.GetConversionFactor();
var widthInches = geoSize.Width * cf / mapScale;
var heightInches = geoSize.Height * cf / mapScale;
// The distortion introduced be orginal map coordinate system may be different along X and Y axes,
// so paper size rectangle may no longer have the same X / Y side ratio as original extents.
// This will result in adjustment of extents in map projection according to this ratio, which is undesirable.
// Let's instead adjust resulting paper size to orignal X / Y ratio.
double newRatio = widthInches / heightInches;
if (!NumericHelper.Equal(newRatio, xyRatio, 1e-6))
{
double correction = Math.Sqrt(newRatio / xyRatio);
heightInches *= correction;
widthInches /= correction;
}
return(new SizeF((float)(widthInches * 100.0), (float)(heightInches * 100.0)));
}
/// <summary>
/// Calculates map scale to fit given extents.
/// </summary>
/// <param name="geoSize">Geodesic size of mapped area in meters.</param>
/// <param name="mapSize">Size of the map on the screen (1/100 of inch).</param>
/// <param name="scaleType">The X and Y scale are often different, this parameter tells how to choose the return value from 2 values available.</param>
/// <returns>Scale of the map.</returns>
public static double CalcMapScale(GeoSize geoSize, SizeF mapSize, ScaleType scaleType = ScaleType.Average)
{
double cf = LengthUnits.Meters.GetConversionFactor();
double scaleX = geoSize.Width / (mapSize.Width / 100.0 / cf);
double scaleY = geoSize.Height / (mapSize.Height / 100.0 / cf);
switch (scaleType)
{
case ScaleType.Average:
return((scaleX + scaleY) / 2.0);
case ScaleType.Smallest:
return(Math.Max(scaleX, scaleY));
case ScaleType.Largest:
return(Math.Min(scaleX, scaleY));
default:
throw new ArgumentOutOfRangeException("scaleType");
}
}
/// <summary>
/// Calculates the size of currently selected map extents in meters
/// </summary>
public static bool GetGeodesicSize(this IPrintableMap map, out GeoSize size)
{
return(GetGeodesicSize(map, map.Extents, out size));
}
////////////////////////////////////////////////////////////////////////////
//--------------------------------- REVISIONS ------------------------------
// Date Name Tracking # Description
// --------- ------------------- ------------- ----------------------
// 18JUN2009 James Shen Initial Creation
////////////////////////////////////////////////////////////////////////////
/**
* Constructs a new <code>GeoBounds</code> whose top left corner is
* (0, 0) and whose Width and Height are specified
* by the <code>GeoSize</code> argument.
* @param size a <code>GeoSize</code>, specifying Width and Height
*/
public GeoLatLngBounds(GeoSize size)
: this(0, 0, size.Width, size.Height)
{
}
////////////////////////////////////////////////////////////////////////////
//--------------------------------- REVISIONS ------------------------------
// Date Name Tracking # Description
// --------- ------------------- ------------- ----------------------
// 18JUN2009 James Shen Initial Creation
////////////////////////////////////////////////////////////////////////////
/**
* Constructs a new <code>GeoBounds</code> whose upper-left corner is
* specified by the GeoPoint argument, and
* whose Width and Height are specified by the
* {@link GeoSize} argument.
* @param p a <code>GeoPoint</code> that is the upper-left corner of
* the <code>GeoBounds</code>
* @param size a <code>GeoSize</code>, representing the
* Width and Height of the <code>GeoBounds</code>
*/
public GeoLatLngBounds(GeoPoint p, GeoSize size)
: this(p.X, p.Y, size.Width, size.Height)
{
}
/// <summary>
/// Calculates new extents of the map given that they must cover certain geo size in meters.
/// </summary>
/// <param name="map">The map.</param>
/// <param name="oldExtents">The extents.</param>
/// <param name="newSize">The new size.</param>
/// <param name="paperSize"></param>
/// <returns>New extents</returns>
public static IEnvelope CalcNewExtents(IPrintableMap map, IEnvelope oldExtents, GeoSize newSize, SizeF paperSize)
{
int depth = 0;
return(CalcNewExtentsCore(map, oldExtents, newSize, paperSize, ref depth));
}
////////////////////////////////////////////////////////////////////////////
//--------------------------------- REVISIONS ------------------------------
// Date Name Tracking # Description
// --------- ------------------- ------------- ----------------------
// 18JUN2009 James Shen Initial Creation
////////////////////////////////////////////////////////////////////////////
/**
* Constructs a new <code>GeoBounds</code> whose top left corner is
* (0, 0) and whose Width and Height are specified
* by the <code>GeoSize</code> argument.
* @param size a <code>GeoSize</code>, specifying Width and Height
*/
public GeoLatLngBounds(GeoSize size)
: this(0, 0, size.Width, size.Height)
{
}
////////////////////////////////////////////////////////////////////////////
//--------------------------------- REVISIONS ------------------------------
// Date Name Tracking # Description
// --------- ------------------- ------------- ----------------------
// 18JUN2009 James Shen Initial Creation
////////////////////////////////////////////////////////////////////////////
/**
* Constructs a new <code>GeoBounds</code> whose upper-left corner is
* specified by the GeoPoint argument, and
* whose Width and Height are specified by the
* {@link GeoSize} argument.
* @param p a <code>GeoPoint</code> that is the upper-left corner of
* the <code>GeoBounds</code>
* @param size a <code>GeoSize</code>, representing the
* Width and Height of the <code>GeoBounds</code>
*/
public GeoLatLngBounds(GeoPoint p, GeoSize size)
: this(p.X, p.Y, size.Width, size.Height)
{
}
