private double GetAngle(TdPoint P, TdPoint O)
{
double angle = Math.Atan((P.Y - O.Y) / (P.X - O.X)) * 180 / Math.PI;
if ((P.X - O.X) >= 0)
{
return(angle);
}
else
{
if ((P.Y - O.Y) >= 0)
{
return(angle + 180);
}
else
{
return(angle - 180);
}
}
}
protected override void OnDraw(Canvas canvas)
{
int cxCompass = MeasuredWidth / 2;
int cyCompass = MeasuredHeight / 2;
float radiusCompass;
if (cxCompass > cyCompass)
{
radiusCompass = (float)(cyCompass * 0.9);
}
else
{
radiusCompass = (float)(cxCompass * 0.9);
}
canvas.DrawCircle(cxCompass, cyCompass, radiusCompass, paint);
canvas.DrawLine(cxCompass - 10, cyCompass, cxCompass + 10, cyCompass, paint);
canvas.DrawLine(cxCompass, cyCompass - 10, cxCompass, cyCompass + 10, paint);
canvas.DrawRect(0, 0, MeasuredWidth, MeasuredHeight, paint);
canvas.DrawText("N", cxCompass, cyCompass - radiusCompass - 10, paint);
canvas.DrawText("S", cxCompass, cyCompass + radiusCompass + 30, paint);
canvas.DrawText("E", cxCompass + radiusCompass + 5, cyCompass, paint);
canvas.DrawText("W", cxCompass - radiusCompass - 30, cyCompass, paint);
if (!firstDraw)
{
TdPoint P1 = new TdPoint();
TdPoint P2 = new TdPoint();
TdPoint P0 = new TdPoint();
TdPoint Ps = new TdPoint();
P0.X = (cxCompass + radiusCompass * Math.Sin((double)(direction - 180 * Values.tyfs) * 3.14 / 180) * (float)(dip / 90));
P0.Y = (cyCompass - radiusCompass * Math.Cos((double)(direction - 180 * Values.tyfs) * 3.14 / 180) * (float)(dip / 90));
P1.X = (cxCompass + radiusCompass * Math.Sin((double)(direction + 90) * 3.14 / 180));
P1.Y = (cyCompass - radiusCompass * Math.Cos((double)(direction + 90) * 3.14 / 180));
P2.X = (cxCompass + radiusCompass * Math.Sin((double)(direction - 90) * 3.14 / 180));
P2.Y = (cyCompass - radiusCompass * Math.Cos((double)(direction - 90) * 3.14 / 180));
Ps.X = (cxCompass + radiusCompass * Math.Sin((double)(Lim360(direction + 180 * Values.tyfs)) * 3.14 / 180) * (1 - dip / 90.0));
Ps.Y = (cyCompass - radiusCompass * Math.Cos((double)(Lim360(direction + 180 * Values.tyfs)) * 3.14 / 180) * (1 - dip / 90.0));
Intersection intersection = new Intersection();
TdLine l1 = intersection.CalMidLine(P1, Ps);
TdLine l2 = intersection.CalMidLine(P2, Ps);
TdPoint Pc = intersection.CalIPoint(l1, l2);
double dist = intersection.Distance(Pc, P1);
//canvas.DrawCircle((float)Pc.X, (float)Pc.Y, (float)dist, paint);//赤平投影圆弧
//canvas.DrawLine((float)Ps.X, (float)Ps.Y, (float)P0.X, (float)P0.Y, paint);//倾角倾向线
canvas.DrawLine((float)P1.X, (float)P1.Y, (float)P2.X, (float)P2.Y, paint);//走向线
RectF re = new RectF((float)(Pc.X - dist), (float)(Pc.Y - dist), (float)(Pc.X + dist), (float)(Pc.Y + dist));
double[] angle = new double[2];
angle[0] = GetAngle(P2, Pc);
angle[1] = GetAngle(P1, Pc);
paint.SetStyle(Paint.Style.Stroke);
if (Math.Abs(angle[1] - angle[0]) >= 180) //层面赤平投影
{
canvas.DrawArc(re, (float)angle[Values.tyfs], (float)(360 - Math.Abs(angle[0] - angle[1])), false, paint);
}
else
{
canvas.DrawArc(re, (float)angle[Values.tyfs], (float)(Math.Abs(angle[1] - angle[0])), false, paint);
}
}
}