static public Vector2DD EquitorialToHorizon(Vector2DD equitorial, Vector2DD location, double jDate)
{
double hourAngle = MstFromUTC2(jDate, location.X) - (equitorial.X * 15);
if (hourAngle < 0)
{
hourAngle += 360.00;
}
double ha = hourAngle * RC;
double dec = equitorial.Y * RC;
double lat = (location.Y) * RC;
double sinAlt = Math.Sin(dec) * Math.Sin(lat) + Math.Cos(dec) * Math.Cos(lat) * Math.Cos(ha);
double altitude = Math.Asin(sinAlt);
double cosAzimith = (Math.Sin(dec) - Math.Sin(altitude) * Math.Sin(lat)) / (Math.Cos(altitude) * Math.Cos(lat));
double azimuth = Math.Acos(cosAzimith);
Vector2DD altAz = new Vector2DD(azimuth/RC, altitude/RC);
if (Math.Sin(ha) > 0)
{
altAz.X = (360 - altAz.X);
}
return altAz;
}
public Bitmap GetChart(double lat, double lng, double time, double ra, double dec, int width, int height)
{
double radius = width/2;
Vector2DD location = new Vector2DD(lng,lat);
Bitmap bmp = new Bitmap(width, height);
Graphics g = Graphics.FromImage(bmp);
g.Clear(Color.White);
g.SmoothingMode = System.Drawing.Drawing2D.SmoothingMode.HighQuality;
//g.DrawEllipse(Pens.Black, );
SolidBrush black = new SolidBrush(Color.Black);
SolidBrush white = new SolidBrush(Color.White);
g.FillEllipse(black, new RectangleF(0, 0, (float)(radius * 2), (float)(radius * 2)));
// draw stars
for (int i = 0; i < stars.Length ; i+=3 )
{
Vector2DD pnt = new Vector2DD(stars[i]/15, stars[i + 1]);
Vector2DD pntOut = Calc.EquitorialToHorizon(pnt, location, time);
pntOut.X -= 90;
double mag = stars[i + 2];
double x = radius - Math.Cos(pntOut.X * Calc.RC) * ((1 - pntOut.Y / 90) * radius);
double y = radius + Math.Sin(pntOut.X * Calc.RC) * ((1 - pntOut.Y / 90) * radius);
double size = (6-mag)*4/5;
//size = 5;
g.FillEllipse(white, new RectangleF((float)(x-(size/2)), (float)(y-(size/2)), (float)size, (float)size));
}
// draw constellation lines
double lastX = 0;
double lastY = 0;
bool first = true;
for (int i = 0; i < figures.Length ; i+=3 )
{
Vector2DD pnt = new Vector2DD(figures[i] , figures[i + 1]);
Vector2DD pntOut = Calc.EquitorialToHorizon(pnt, location, time);
pntOut.X -= 90;
double x = radius - Math.Cos(pntOut.X * Calc.RC) * ((1 - pntOut.Y / 90) * radius);
double y = radius + Math.Sin(pntOut.X * Calc.RC) * ((1 - pntOut.Y / 90) * radius);
if (figures[i + 2] == 0 || first)
{
first = false;
}
else
{
if (pntOut.Y > -20)
{
g.DrawLine(Pens.White, new PointF((float)x, (float)y), new PointF((float)lastX, (float)lastY));
}
}
lastX = x;
lastY = y;
}
// draw ecliptic
// draw planets / moon
// draw labels
// draw target
//return bitmap
//Clean up
black.Dispose();
white.Dispose();
g.Flush();
g.Dispose();
return bmp;
}
