/**
* Creates a elliptical arc, as a LineString.
*
* @return an elliptical arc
*/
public LineString createArc(double startAng, double endAng) {
Envelope env = dim.getEnvelope();
double xRadius = env.getWidth() / 2.0;
double yRadius = env.getHeight() / 2.0;
double centreX = env.getMinX() + xRadius;
double centreY = env.getMinY() + yRadius;
double angSize = (endAng - startAng);
if (angSize <= 0.0 || angSize > 2 * Math.PI) angSize = 2 * Math.PI;
double angInc = angSize / nPts;
Coordinate[] pts = new Coordinate[nPts];
int iPt = 0;
for (int i = 0; i < nPts; i++) {
double ang = startAng + i * angInc;
double x = xRadius * Math.cos(ang) + centreX;
double y = yRadius * Math.sin(ang) + centreY;
Coordinate pt = new Coordinate(x, y);
geomFact.getPrecisionModel().makePrecise(pt);
pts[iPt++] = pt;
}
LineString line = geomFact.createLineString(pts);
return line;
}
/**
* Creates a rectangular {@link Polygon}.
*
* @return a rectangular Polygon
*/
public Polygon createRectangle() {
int i;
int ipt = 0;
int nSide = nPts / 4;
if (nSide < 1) nSide = 1;
double XsegLen = dim.getEnvelope().getWidth() / nSide;
double YsegLen = dim.getEnvelope().getHeight() / nSide;
Coordinate[] pts = new Coordinate[4 * nSide + 1];
Envelope env = dim.getEnvelope();
double maxx = env.getMinX() + nSide * XsegLen;
double maxy = env.getMinY() + nSide * XsegLen;
for (i = 0; i < nSide; i++) {
double x = env.getMinX() + i * XsegLen;
double y = env.getMinY();
pts[ipt++] = new Coordinate(x, y);
}
for (i = 0; i < nSide; i++) {
double x = env.getMaxX();
double y = env.getMinY() + i * YsegLen;
pts[ipt++] = new Coordinate(x, y);
}
for (i = 0; i < nSide; i++) {
double x = env.getMaxX() - i * XsegLen;
double y = env.getMaxY();
pts[ipt++] = new Coordinate(x, y);
}
for (i = 0; i < nSide; i++) {
double x = env.getMinX();
double y = env.getMaxY() - i * YsegLen;
pts[ipt++] = new Coordinate(x, y);
}
pts[ipt++] = new Coordinate(pts[0]);
LinearRing ring = geomFact.createLinearRing(pts);
Polygon poly = geomFact.createPolygon(ring, null);
return poly;
}
/**
* Creates a circular {@link Polygon}.
*
* @return a circle
*/
public Polygon createCircle() {
Envelope env = dim.getEnvelope();
double xRadius = env.getWidth() / 2.0;
double yRadius = env.getHeight() / 2.0;
double centreX = env.getMinX() + xRadius;
double centreY = env.getMinY() + yRadius;
Coordinate[] pts = new Coordinate[nPts + 1];
int iPt = 0;
for (int i = 0; i < nPts; i++) {
double ang = i * (2 * Math.PI / nPts);
double x = xRadius * Math.cos(ang) + centreX;
double y = yRadius * Math.sin(ang) + centreY;
Coordinate pt = new Coordinate(x, y);
pts[iPt++] = pt;
}
pts[iPt] = pts[0];
LinearRing ring = geomFact.createLinearRing(pts);
Polygon poly = geomFact.createPolygon(ring, null);
return poly;
}