//http://www.chrobotics.com/library/understanding-euler-angles
// x = north / roll
// y = pitch / east
// z = yaw / down
public static List <PointLatLngAlt> calc(PointLatLngAlt plla, double R, double P, double Y, double hfov, double vfov)
{
// alt should be asl
// P pitch where the center os pointing ie -80
// R roll
// if roll and pitch is 0, use the quick method.
if (R == 0 && P == 0)
{
// calc fov in m on the ground at 0 alt
var fovh = Math.Tan(hfov / 2.0 * deg2rad) * plla.Alt;
var fovv = Math.Tan(vfov / 2.0 * deg2rad) * plla.Alt;
var fovd = Math.Sqrt(fovh * fovh + fovv * fovv);
// where we put our footprint
var ans2 = new List <PointLatLngAlt>();
// calc bearing from center to corner
var bearing1 = Math.Atan2(fovh, fovv) * rad2deg;
// calc first corner point
var newpos1 = plla.newpos(bearing1 + Y, Math.Sqrt(fovh * fovh + fovv * fovv));
// set alt to 0, as we used the hypot for distance and fov is based on 0 alt
newpos1.Alt = 0;
// calc intersection from center to new point and return ground hit point
var cen1 = calcIntersection(plla, newpos1);
// add to our footprint poly
ans2.Add(cen1);
addtomap(cen1, "cen1");
//repeat
newpos1 = plla.newpos(Y - bearing1, Math.Sqrt(fovh * fovh + fovv * fovv));
newpos1.Alt = 0;
cen1 = calcIntersection(plla, newpos1);
ans2.Add(cen1);
addtomap(cen1, "cen2");
newpos1 = plla.newpos(bearing1 + Y - 180, Math.Sqrt(fovh * fovh + fovv * fovv));
newpos1.Alt = 0;
cen1 = calcIntersection(plla, newpos1);
ans2.Add(cen1);
addtomap(cen1, "cen3");
newpos1 = plla.newpos(Y - bearing1 - 180, Math.Sqrt(fovh * fovh + fovv * fovv));
newpos1.Alt = 0;
cen1 = calcIntersection(plla, newpos1);
ans2.Add(cen1);
addtomap(cen1, "cen4");
addtomap(plla, "plane");
return(ans2);
}
GMapPolygon poly = new GMapPolygon(new List <PointLatLng>(), "rect");
double frontangle = (P * 0) + vfov / 2;
double backangle = (P * 0) - vfov / 2;
double leftangle = (R * 0) + hfov / 2;
double rightangle = (R * 0) - hfov / 2;
addtomap(plla, "plane");
Matrix3 dcm = new Matrix3();
dcm.from_euler(R * deg2rad, P * deg2rad, Y * deg2rad);
dcm.normalize();
Vector3 center1 = new Vector3(0, 0, 10000);
var test = dcm * center1;
var bearing2 = Math.Atan2(test.y, test.x) * rad2deg;
var newpos2 = plla.newpos(bearing2, Math.Sqrt(test.x * test.x + test.y * test.y));
newpos2.Alt -= test.z;
var cen = calcIntersection(plla, newpos2);
var dist = plla.GetDistance(cen);
addtomap(cen, "center " + dist.ToString("0"));
//
dcm.from_euler(R * deg2rad, P * deg2rad, Y * deg2rad);
dcm.rotate(new Vector3(rightangle * deg2rad, 0, 0));
dcm.normalize();
dcm.rotate(new Vector3(0, frontangle * deg2rad, 0));
dcm.normalize();
/*
* var mx = new Matrix3();
* var my = new Matrix3();
* var mz = new Matrix3();
*
* mx.from_euler((rightangle + R) * deg2rad, 0, 0);
* my.from_euler(0, (frontangle + P) * deg2rad, 0);
* mz.from_euler(0, 0, Y * deg2rad);
*
* printdcm(mx);
* printdcm(my);
* printdcm(mz);
* printdcm(my * mx);
* printdcm(mz * my * mx);
*
* test = mz * my * mx * center1;
*/
test = dcm * center1;
bearing2 = (Math.Atan2(test.y, test.x) * rad2deg);
newpos2 = plla.newpos(bearing2, Math.Sqrt(test.x * test.x + test.y * test.y));
newpos2.Alt -= test.z;
//addtomap(newpos2, "tr2");
var groundpointtr = calcIntersection(plla, newpos2);
poly.Points.Add(groundpointtr);
addtomap(groundpointtr, "tr");
//
dcm.from_euler(R * deg2rad, P * deg2rad, Y * deg2rad);
dcm.rotate(new Vector3(leftangle * deg2rad, 0, 0));
dcm.normalize();
dcm.rotate(new Vector3(0, frontangle * deg2rad, 0));
dcm.normalize();
test = dcm * center1;
bearing2 = Math.Atan2(test.y, test.x) * rad2deg;
newpos2 = plla.newpos(bearing2, Math.Sqrt(test.x * test.x + test.y * test.y));
newpos2.Alt -= test.z;
var groundpointtl = calcIntersection(plla, newpos2);
poly.Points.Add(groundpointtl);
addtomap(groundpointtl, "tl");
//
dcm.from_euler(R * deg2rad, P * deg2rad, Y * deg2rad);
dcm.rotate(new Vector3(leftangle * deg2rad, 0, 0));
dcm.normalize();
dcm.rotate(new Vector3(0, backangle * deg2rad, 0));
dcm.normalize();
test = dcm * center1;
bearing2 = Math.Atan2(test.y, test.x) * rad2deg;
newpos2 = plla.newpos(bearing2, Math.Sqrt(test.x * test.x + test.y * test.y));
newpos2.Alt -= test.z;
var groundpointbl = calcIntersection(plla, newpos2);
poly.Points.Add(groundpointbl);
addtomap(groundpointbl, "bl");
//
dcm.from_euler(R * deg2rad, P * deg2rad, Y * deg2rad);
dcm.rotate(new Vector3(rightangle * deg2rad, 0, 0));
dcm.normalize();
dcm.rotate(new Vector3(0, backangle * deg2rad, 0));
dcm.normalize();
test = dcm * center1;
bearing2 = Math.Atan2(test.y, test.x) * rad2deg;
newpos2 = plla.newpos(bearing2, Math.Sqrt(test.x * test.x + test.y * test.y));
newpos2.Alt -= test.z;
var groundpointbr = calcIntersection(plla, newpos2);
poly.Points.Add(groundpointbr);
addtomap(groundpointbr, "br");
//
polygons.Polygons.Clear();
polygons.Polygons.Add(poly);
var ans = new List <PointLatLngAlt>();
ans.Add(groundpointtl);
ans.Add(groundpointtr);
ans.Add(groundpointbr);
ans.Add(groundpointbl);
return(ans);
}