Class Flann

src/main/java/marc/math/Flann.java:16–300

import java.util.function.Function;

public class Flann {

    static {
        if (Main.os == Main.OS.mac)
            System.loadLibrary("JNanoFlann");
        else
            System.loadLibrary("jnanoflann");
    }

    private long cloud = -1;
    private boolean is2d = false;
    private LongBuffer cache;
    private FloatBuffer allocated;

    public Flann() {

    }

    // test
    static public void main(String[] a) {

        {
            int num = 1000000;
            FloatBuffer f = ByteBuffer.allocateDirect(4 * num * 3)
                    .order(ByteOrder.nativeOrder())
                    .asFloatBuffer();
            for (int i = 0; i < num; i++) {
                f.put((float) Math.random());
                f.put((float) Math.random());
                f.put((float) Math.random());
            }
            f.rewind();

            Flann flann = new Flann();
            long cloud = flann.build3(f, num);

            Log.log("flann", () -> "got :" + cloud);

            Vec3 v = new Vec3(Math.random(), Math.random(), Math.random());
            int c = flann.closest3(cloud, (float) v.x, (float) v.y, (float) v.z);

            Log.log("flann", () -> "closest is :" + c + "  to " + v + " is " + f.get(c * 3 + 0) + " " + f.get(
                    c * 3 + 1) + " " + f
                    .get(c * 3 + 2) + "  " + new Vec3(3 * c, f));

            Log.log("flann",
                    () -> "distance is " + new Vec3(3 * c, f).distance(v) + " " + new Vec3(3 * c, f).distanceSquared(
                            v));

            LongBuffer out = ByteBuffer.allocateDirect(8 * 10)
                    .order(ByteOrder.nativeOrder())
                    .asLongBuffer();

            flann.closestN3(cloud, (float) v.x, (float) v.y, (float) v.z, out, 10);


            flann.free3(cloud);
        }