BauSystem/BauSystem_Main/src/de/steamwar/bausystem/tracer/TraceCache.java

package de.steamwar.bausystem.tracer;

import org.bukkit.entity.Player;

import java.util.*;

public class TraceCache {

    private static final Set<Loc> empty = new HashSet();
    private Map<String, Set<Loc>> playerMap = new HashMap<>();
    private Map<String, TracerUpdater.DisplayMode> playerDisplayMap = new HashMap<>();

    public Set<Loc> get(Player player) {
        return playerMap.getOrDefault(player.getUniqueId().toString(), empty);
    }

    public Set<Loc> update(Player player, TracerUpdater tracerUpdater, boolean dirty) {
        if (!dirty) return empty;
        String key = player.getUniqueId().toString();
        Set<Loc> locOld;
        TracerUpdater.DisplayMode displayMode;
        if (!playerMap.containsKey(key)) {
            locOld = new HashSet<>();
            displayMode = tracerUpdater.getDisplayType(player);
        } else {
            locOld = playerMap.get(key);
            displayMode = playerDisplayMap.get(key);
        }

        Set<Loc> locSet = new HashSet<>();
        tracerUpdater.updatePoints(player).forEach(loc -> {
            loc.updatePoint = true;
            locSet.add(loc);
        });
        tracerUpdater.updateLocations(player).forEach(loc -> {
            loc.updatePoint = false;
            locSet.add(loc);
        });

        playerMap.put(key, locSet);
        TracerUpdater.DisplayMode currentMode = tracerUpdater.getDisplayType(player);
        playerDisplayMap.put(key, currentMode);

        if (currentMode == TracerUpdater.DisplayMode.Particle && displayMode == TracerUpdater.DisplayMode.Block) return locOld;
        if (currentMode == TracerUpdater.DisplayMode.Block) return diff(locOld, locSet);
        return empty;
    }

    public static class Loc {
        public final float x;
        public final float y;
        public final float z;

        private final float dx;
        private final float dy;
        private final float dz;

        public boolean updatePoint = false;

        public Loc(float x, float y, float z) {
            this.x = x;
            this.y = y;
            this.z = z;
            this.dx = round(x);
            this.dy = round(y);
            this.dz = round(z);
        }

        private static int roundNumber = 10;
        private static float round(float toRound) {
            float r = (toRound * roundNumber);
            float t = r - (int) r;
            if (t >= 0.5) {
                return (((float)(int)r) + 1) / roundNumber;
            } else {
                return (((float)(int)r) + 0) / roundNumber;
            }
        }

        @Override
        public boolean equals(Object o) {
            if (this == o) return true;
            if (!(o instanceof Loc)) return false;
            Loc loc = (Loc) o;
            return Float.compare(loc.dx, dx) == 0 &&
                    Float.compare(loc.dy, dy) == 0 &&
                    Float.compare(loc.dz, dz) == 0;
        }

        @Override
        public int hashCode() {
            return Objects.hash(dx, dy, dz);
        }

        @Override
        public String toString() {
            return "Loc{" +
                    "x=" + x +
                    ", y=" + y +
                    ", z=" + z +
                    '}';
        }

        public boolean remove(Player player, double radius) {
            double x = player.getLocation().getX();
            double y = player.getLocation().getY();
            double z = player.getLocation().getZ();

            double dx = (this.x - x) * (this.x - x);
            double dy = (this.y - y) * (this.y - y);
            double dz = (this.z - z) * (this.z - z);

            return (dx + dy + dz) > radius * radius;
        }
    }

    private Set<Loc> diff(Set<Loc> locOld, Set<Loc> locNew) {
        if (locOld.isEmpty()) return empty;
        if (locNew.isEmpty()) return locOld;
        for (Loc l : locNew) {
            locOld.remove(l);
        }
        return locOld;
    }

}