public IObservable<Unit> addMap(Map map, System.IO.Stream mapContent)
{
Func<Task> impl = async () =>
{
try
{
using (var iso = IsolatedStorageFile.GetUserStoreForApplication())
{
var filename = fileNameForMap(map);
if (iso.FileExists(filename))
iso.DeleteFile(filename);
using (var file = iso.CreateFile(filename))
{
await mapContent.CopyToAsync(file, 4 * 1024 * 1024);
}
}
}
catch (IsolatedStorageException)
{
mapContent.Dispose();
}
using (var ctx = getContext())
{
ctx.Maps.InsertOnSubmit(map);
ctx.SubmitChanges();
}
};
return impl().ToObservable();
}
private string fileNameForMap(Map map)
{
return string.Format("{0}/{1}.png", MapFolder, map.ServerKey);
}
public void deleteMap(Map map)
{
using (var iso = IsolatedStorageFile.GetUserStoreForApplication())
{
var filename = fileNameForMap(map);
if (iso.FileExists(filename))
iso.DeleteFile(filename);
}
using (var ctx = getContext())
{
ctx.Maps.Attach(map);
ctx.Maps.DeleteOnSubmit(map);
ctx.SubmitChanges();
}
}
public System.IO.Stream loadMap(Map map)
{
#if false
var splash = "Images/AppIcons/DivMob_QuadratEnd_s_Splash.png";
var resource = App.GetResourceStream(new Uri(splash, UriKind.Relative));
if (resource != null) return resource.Stream;
#endif
var iso = IsolatedStorageFile.GetUserStoreForApplication();
var filename = fileNameForMap(map);
if (iso.FileExists(filename))
{
return iso.OpenFile(filename, System.IO.FileMode.Open);
}
else
return null;
}
//The corner coordinates of the map dont define an exact rectangle in all cases. Generally, a convex quadrangle is defined.
//The represetation on the screen will be in an rectangle. Hence, the corresponding position is calculated. To perform This,
//2 lines are definend: One Going from the upper-left corner to the upper right corner of the map. The other one from the lower left corner to the lower right corner of the map.
//A cohort of lines is definend by the connection between those lines parametrized by the percentual scale between the cornerpoint of the 2 lines definend in This way.
//Analogously 2 lines are definend in the y-Direction which also define a cohort of lines between them. The GPS-Value is at a specific intersection of these cohorts.
//These specific lines of the cohorts can be found by solving a quadratic equation. Theses lines define with their parameters the position of the GPS-Value on the map (On a percentual basis).
private static Point? PercentilePositionOnMapImpl(Map This, double GPSLatitude, double GPSLongitude)
{
double a, b, c, d, e, f, g, h; //This-specific values derived form the position of the cornerpoints. a and e are dependent on addtional values and calculated in the position calculation method
bool specialCase;//Criterion for the special case mu=-b/d (which leads to a division by zero in the lambda calculus)
a = -GPSLongitude + This.NWLong;
b = -This.NWLong + This.NELong;
c = -This.NWLong + This.SWLong;
d = This.NWLong - This.NELong + This.SELong - This.SWLong;
e = -GPSLatitude + This.NWLat;
f = -This.NWLat + This.NELat;
g = -This.NWLat + This.SWLat;
h = This.NWLat - This.NELat + This.SELat - This.SWLat;
if (b == 0 || g == 0)
{
//This coordinates are corrupted
return null;
}
//Check d==0
if (d != 0)
{
if (a - c * b / d == 0)
specialCase = true;
else
specialCase = false;
}
else
specialCase = false;
if (specialCase == false) //=>mu!=-b/d
{
double alpha, beta, gamma;//Coeffizients for the Mitternachts-Equation
double discrim;//Discriminant in the Mitternachts-Equation
double mu1, mu2, lambda1, lambda2;//Solution-Parameters. As the equation is quadratic two possible solutions exist.
alpha = g * d - h * c;
beta = e * d - c * f + g * b - a * h;
gamma = -a * f + e * b;
if (alpha != 0)
{
discrim = beta * beta - 4 * alpha * gamma;
if (discrim < 0) //Equation unsovable
return null;
mu1 = (-beta + Math.Sqrt(discrim)) / (2 * alpha);
mu2 = (-beta - Math.Sqrt(discrim)) / (2 * alpha);
lambda1 = -(a + c * mu1) / (b + d * mu1);
lambda2 = -(a + c * mu2) / (b + d * mu2);
Point p1 = new Point(lambda1, mu1);
Point p2 = new Point(lambda2, mu2);
if (p1.X > 0 && p1.X < 1 && p1.Y > 0 && p1.Y < 1)
return p1;
if (p2.X > 0 && p2.X < 1 && p2.Y > 0 && p2.Y < 1)
return p2;
return null;
}
else
{
if (beta != 0)
{
mu1 = -gamma / beta;
lambda1 = -(a + c * mu1) / (b + d * mu1);
Point p1 = new Point(lambda1, mu1);
if (p1.X > 0 && p1.X < 1 && p1.Y > 0 && p1.Y < 1)
return p1;
return null;
}
else
{
//No mu-Percentile can be calculated as the equation is either unsovable or there are no restriction to mu.
//In both cases no representation on the This can be given
return null;
}
}
}
else //=> mu=-b/d
{
double lambda, mu;
mu = -b / d;
if (b * h - f * c != 0)
{
lambda = -(e * d - b * g) / (b * h - f * c);//Div by Zero
Point p = new Point(lambda, mu);
return p;
}
else
{
//No mu-Percentile can be calculated as the equation is either unsovable or there are no restriction to mu.
//In both cases no representation on the This can be given
return null;
}
}
}
