public void CalculatePoints(ViewportFoV viewport)
{
// calculate the lines based on fov height and current dec to avoid projection issues
// atan gnomoric projection cannot project properly over 90deg, it will result in the same results as prior
// and dec lines will overlap each other
var(raStep, decStep, raStart, raStop, decStart, decStop) = CalculateStepsAndStartStopValues(viewport);
var pointsByDecDict = new Dictionary <double, FrameLine>();
// if raStep is 30 and decStep is 1 just
bool raIsClosed = RoundToHigherValue(viewport.AbsCalcTopDec, decStep) >= MAXDEC;
for (double ra = Math.Min(raStart, raStop);
ra <= Math.Max(raStop, raStart);
ra += raStep)
{
List <PointF> raPointCollection = new List <PointF>();
for (double dec = Math.Min(decStart, decStop);
dec <= Math.Max(decStart, decStop);
dec += decStep)
{
var point = new Coordinates(ra, dec, Epoch.J2000, Coordinates.RAType.Degrees).XYProjection(viewport);
var pointf = new PointF((float)point.X, (float)point.Y);
if (!pointsByDecDict.ContainsKey(dec))
{
pointsByDecDict.Add(dec, new FrameLine()
{
Closed = raIsClosed, Collection = new List <PointF> {
pointf
}, StrokeThickness = dec == 0 ? 3 : 1
});
}
else
{
pointsByDecDict[dec].Collection.Add(pointf);
}
raPointCollection.Add(pointf);
}
// those are the vertical lines
RAPoints.Add(new FrameLine {
StrokeThickness = (ra == 0 || ra == 180) ? 3 : 1,
Closed = false,
Collection = raPointCollection
});
}
// those are actually the circles
foreach (KeyValuePair <double, FrameLine> item in pointsByDecDict)
{
DecPoints.Add(item.Value);
}
}
/// <summary>
/// Calculates the circles (or curved lines when not completely in view)
/// </summary>
/// <param name="viewport"></param>
/// <param name="dec"></param>
private void CalculateDecPoints(double dec)
{
var thickness = dec == 0 ? 3 : 1;
var coordinates = decCoordinateMatrix[dec];
var center = currentViewport.CenterCoordinates;
var startRA = coordinates.Aggregate((x, y) => Math.Abs(x.RADegrees - center.RADegrees) < Math.Abs(y.RADegrees - center.RADegrees) ? x : y);
var startIdx = coordinates.FindIndex(x => startRA.RADegrees == x.RADegrees);
var iterator = 0;
var list = new LinkedList <PointF>();
if (currentViewport.ContainsCoordinates(startRA))
{
var pointF = Project(startRA);
list.AddLast(pointF);
do
{
iterator++;
var rightCoordinate = coordinates[(int)nfmod((startIdx + iterator), coordinates.Count)];
var leftCoordinate = coordinates[(int)nfmod((startIdx - iterator), coordinates.Count)];
var leftPointF = Project(leftCoordinate);
var rightPointF = Project(rightCoordinate);
list.AddLast(leftPointF);
list.AddFirst(rightPointF);
if (!currentViewport.ContainsCoordinates(leftCoordinate) && !currentViewport.ContainsCoordinates(rightCoordinate))
{
break;
}
} while (iterator <= coordinates.Count / 2d);
}
DecPoints.Add(new FrameLine()
{
Collection = new List <PointF>(list), StrokeThickness = thickness, Closed = false, Angle = Angle.ByDegree(dec)
});
}