/************************** END RECT *******************************/
#endregion
#region parse_POLYGON
/* ******************************************** POLY ***/
private bool parse_polygon() {
Region region = _targetregion;
Polygon poly = null;
int npoints = 0;
double ra, dec, x, y, z;
if (region == null)
return true;
advance(); // Skip over 'RECT'
_format = peekFormat();
if (ismore && _format != Format.Null) {
advance();
}
while (ismore) {
if (npoints >= this._current_capacity) {
_error = Error.errPolyToomanyPoints;
return isok;
}
switch (_format) {
case Format.Null:
case Format.Cartesian:
try {
x = this.getdouble();
y = this.getdouble();
z = this.getdouble();
} catch {
if (_error != Error.errEol)
_error = Error.errIllegalNumber;
return isok;
}
xs[npoints] = x;
ys[npoints] = y;
zs[npoints] = z;
npoints++;
break;
case Format.J2000:
case Format.Latlon:
try {
ra = this.getdouble();
dec = this.getdouble();
} catch {
if (_error != Error.errEol)
_error = Error.errIllegalNumber;
return isok;
}
if (_format == Format.Latlon) {
SpatialVector.radec2cartesian(dec, ra, out x, out y, out z);
} else {
SpatialVector.radec2cartesian(ra, dec, out x, out y, out z);
}
xs[npoints] = x;
ys[npoints] = y;
zs[npoints] = z;
npoints++;
break;
default:
break;
}
}
if (npoints < 3) {
_error = Error.errNot2forRect;
return isok;
}
poly = new Polygon(region);
// WARNING!!! more than one kinf of error. The other one is for
// degenerate edges, two points are too close... or you can eliminate them!
Polygon.Error err = poly.add(xs, ys, zs, npoints);
if (err == Polygon.Error.errBowtieOrConcave) {
_error = Error.errPolyBowtie;
return isok;
} else if (err == Polygon.Error.errZeroLength){
_error = Error.errPolyZeroLength;
return isok;
}
return true;
}
public bool addConvex(double[] x, double[] y, double[] z, int len){
//
// All the input points are in x,y,z...
// To make a convex hull, follow these steps:
// 1. add all the points to the internal array
// 2. compute the centroid
// 3. make the rotation matrix, that rotates the centroid to (x,y,0)
// 4. rotate the points (call xform, returns error if more than hemisphere)
// 5. sort (by x,y)
// 6. compute the convex hull, result is a polygon
// 7. Call the polygoner to make the convex
// todo: encapsulate Polygon into Chull, or use inheritance?
//
if (_reg == null)
return true;
CPoint centroid = new CPoint();
for(int i=0; i<len; i++){
addPoint(x[i], y[i], z[i]);
}
this.nPoints = len;
this.getCentroid( centroid);
this.makeRotator(centroid);
if (this.xform()){
this.sort();
nrKept = this.chainHull_2D();
// output has it all
// allmost like Polygon, except first point is included at end
// We can now make a polygon out of it. Luckily it takes
// care of the winding error
//
// First, move over the x,y,z points to double arrays;
//
double[] xa, ya, za;
CPoint p;
xa = new double[nrKept];
ya = new double[nrKept];
za = new double[nrKept];
for(int i=0; i<nrKept; i++){
p = (CPoint) output[i];
xa[i] = p.x_in;
ya[i] = p.y_in;
za[i] = p.z_in;
}
Polygon poly = new Polygon(this._reg);
poly.add(xa, ya, za, nrKept-1); // because first connects to last
} else {
//
// Error, points were more than a hemisphere
//
return false;
}
return true;
}