Re: Creating a shape from a set of points
Peter Duniho wrote:
Jeff Higgins wrote:
Now I'm wondering about a spiral shape,
something like a loosly coiled length of rope.
How to find the outline of the rope?
Well, that goes back to the definition of "boundary". Assuming we're
defining it based on dot density, then as long as the negative area around
the "rope" is completely empty and satisfies the dot density requirement
for "outside", there shouldn't be a problem.
Other definitions of "boundary" may indeed run into issues with a shape
like that. Personally, I don't think that either "shrink wrap" or "vacuum
wrap" are very good ways of describing the problem. The "shrink wrap"
description has obvious problems, but "vacuum wrap" is really just a
slightly different packaging technique that uses the same sort of "outside
surface pulled inward" process that "shrink wrap" does. As such, "vacuum
wrap" doesn't deal with a "spiral rope" any better than "shrink wrap"
would. :)
Back to the 'C' example.
I hope Todd returns with a solution to his problem.
import java.awt.*;
import java.util.*;
public class Points {
public static void main(String[] args) {
Set<Point> sparse = new HashSet<Point>(100);
Set<Point> dense = new HashSet<Point>(1200);
Path2D path = new Path2D.Double();
path.moveTo(0.0, 0.0);
path.lineTo(40.0, 0.0);
path.lineTo(40.0, 10.0);
path.lineTo(10.0, 10.0);
path.lineTo(10.0, 50.0);
path.lineTo(40.0, 50.0);
path.lineTo(40.0, 60.0);
path.lineTo(0.0, 60.0);
path.closePath();
Random r = new Random();
for (int i = 0; i < 100; i++) {
Point p = new Point(r.nextInt(40), r.nextInt(60));
if (path.contains(p))
sparse.add(p); }
for (int x = 0; x < 41; x++) {
for (int y = 0; y < 11; y++) {
dense.add(new Point(x, y)); } }
for (int x = 0; x < 11; x++) {
for (int y = 11; y < 51; y++) {
dense.add(new Point(x, y)); } }
for (int x = 0; x < 41; x++) {
for (int y = 51; y < 61; y++) {
dense.add(new Point(x, y)); } }
}
}