@Override
public Geom buffer(double amt, Linearizer linearizer, Tolerance tolerance)
throws IllegalArgumentException, NullPointerException {
if (amt == 0) {
return this;
} else if (amt < 0) {
return null;
}
VectList result = new VectList();
VectBuilder vect = new VectBuilder();
projectOutward(0, -amt, tolerance, vect);
double ix = vect.getX();
double iy = vect.getY();
result.add(ix, iy);
projectOutward(0, amt, tolerance, vect);
linearizer.linearizeSegment(ax, ay, ix, iy, vect.getX(), vect.getY(), result);
projectOutward(1, amt, tolerance, vect);
double jx = vect.getX();
double jy = vect.getY();
result.add(jx, jy);
projectOutward(1, -amt, tolerance, vect);
linearizer.linearizeSegment(bx, by, jx, jy, vect.getX(), vect.getY(), result);
result.add(ix, iy);
return new Area(new Ring(result, null));
}
static void intersectionLineCircleInternal(
double ax,
double ay,
double bx,
double by,
double cx,
double cy,
double radius,
Tolerance tolerance,
VectBuilder working,
VectList intersections) {
projectOnToLineInternal(
ax, ay, bx, by, cx, cy, tolerance,
working); // get the closest point on the line to the circle center
double dx = working.getX();
double dy = working.getY();
double distToLineSq = Vect.distSq(cx, cy, dx, dy);
double radiusSq = radius * radius;
switch (tolerance.check(distToLineSq - radiusSq)) {
case 1: // dist to line is greater than radius - line does not intersect circle
return;
case 0: // dist to line matches radius - line touches circle
intersections.add(dx, dy);
return;
default: // dist to line is less than radius - line crosses circle
double mx = bx - ax;
double my = by - ay;
double segmentLen = Math.sqrt(mx * mx + my * my);
double projectDist;
if (tolerance.check(distToLineSq) == 0) { // line crosses circle center
projectDist = radius;
dx = cx;
dy = cy;
} else {
projectDist = Math.sqrt(radiusSq - distToLineSq);
}
double mul = projectDist / segmentLen;
mx *= mul;
my *= mul;
intersections.add(dx - mx, dy - my);
intersections.add(dx + mx, dy + my);
}
}
