Track which spells are active on which blocks to make tile-by-tile interactions easier. Requireed by #412

src/main/java/com/minelittlepony/unicopia/Unicopia.java

@@ -31,6 +31,7 @@ import com.minelittlepony.unicopia.item.enchantment.UEnchantments;
 import com.minelittlepony.unicopia.network.Channel;
 import com.minelittlepony.unicopia.particle.UParticles;
 import com.minelittlepony.unicopia.server.world.BlockDestructionManager;
+import com.minelittlepony.unicopia.server.world.Ether;
 import com.minelittlepony.unicopia.server.world.NocturnalSleepManager;
 import com.minelittlepony.unicopia.server.world.UGameRules;
 import com.minelittlepony.unicopia.server.world.UWorldGen;
@@ -71,6 +72,7 @@ public class Unicopia implements ModInitializer {
             ((BlockDestructionManager.Source)w).getDestructionManager().tick();
             ZapAppleStageStore.get(w).tick();
             WeatherConditions.get(w).tick();
+            Ether.get(w).tick();
             if (Debug.SPELLBOOK_CHAPTERS) {
                 SpellbookChapterLoader.INSTANCE.sendUpdate(w.getServer());
             }

src/main/java/com/minelittlepony/unicopia/server/world/Ether.java

@@ -13,14 +13,18 @@ import com.minelittlepony.unicopia.ability.magic.Caster;
 import com.minelittlepony.unicopia.ability.magic.spell.Spell;
 import com.minelittlepony.unicopia.ability.magic.spell.effect.SpellType;
 import com.minelittlepony.unicopia.entity.EntityReference;
+import com.minelittlepony.unicopia.server.world.chunk.PositionalDataMap;
 import com.minelittlepony.unicopia.util.NbtSerialisable;
+import com.minelittlepony.unicopia.util.Tickable;
+
 import net.minecraft.nbt.*;
 import net.minecraft.util.Identifier;
+import net.minecraft.util.math.BlockPos;
 import net.minecraft.util.math.MathHelper;
 import net.minecraft.world.PersistentState;
 import net.minecraft.world.World;
 
-public class Ether extends PersistentState {
+public class Ether extends PersistentState implements Tickable {
     private static final Identifier ID = Unicopia.id("ether");
 
     public static Ether get(World world) {
@@ -28,6 +32,7 @@ public class Ether extends PersistentState {
     }
 
     private final Map<Identifier, Map<UUID, Map<UUID, Entry<?>>>> endpoints;
+    private final PositionalDataMap<Entry<?>> positionData = new PositionalDataMap<>();
 
     private final Object locker = new Object();
 
@@ -70,23 +75,36 @@ public class Ether extends PersistentState {
                         markDirty();
                         return new Entry<>(spell, caster);
                     });
-            if (entry.removed) {
+
-                entry.removed = false;
-                markDirty();
-            }
             if (entry.spell.get() != spell) {
                 entry.spell = new WeakReference<>(spell);
                 markDirty();
             }
+            if (entry.removed) {
+                entry.removed = false;
+                positionData.update(entry);
+                markDirty();
+            }
             return entry;
         }
     }
 
+    @Override
+    public void tick() {
+        endpoints.values().forEach(byType -> {
+            byType.values().forEach(entries -> {
+                entries.values().forEach(Entry::update);
+            });
+        });
+    }
+
     public <T extends Spell> void remove(SpellType<T> spellType, UUID entityId) {
         synchronized (locker) {
             endpoints.computeIfPresent(spellType.getId(), (typeId, entries) -> {
-                if (entries.remove(entityId) != null) {
+                Map<UUID, Entry<?>> data = entries.remove(entityId);
+                if (data != null) {
                     markDirty();
+                    data.values().forEach(positionData::remove);
                 }
                 return entries.isEmpty() ? null : entries;
             });
@@ -150,6 +168,10 @@ public class Ether extends PersistentState {
         return false;
     }
 
+    public Set<Entry<?>> getAtPosition(BlockPos pos) {
+        return world.isClient() ? Set.of() : positionData.getState(pos);
+    }
+
     private void pruneNodes() {
         this.endpoints.values().removeIf(entities -> {
             entities.values().removeIf(spells -> {
@@ -160,7 +182,7 @@ public class Ether extends PersistentState {
         });
     }
 
-    public class Entry<T extends Spell> implements NbtSerialisable {
+    public class Entry<T extends Spell> implements PositionalDataMap.Hotspot, NbtSerialisable {
         public final EntityReference<?> entity;
 
         @Nullable
@@ -176,6 +198,9 @@ public class Ether extends PersistentState {
 
         private final Set<UUID> claimants = new HashSet<>();
 
+        private BlockPos currentPos = BlockPos.ORIGIN;
+        private BlockPos previousPos = BlockPos.ORIGIN;
+
         private Entry(NbtElement nbt) {
             this.entity = new EntityReference<>();
             this.spell = new WeakReference<>(null);
@@ -186,6 +211,15 @@ public class Ether extends PersistentState {
             this.entity = new EntityReference<>(caster.asEntity());
             this.spell = new WeakReference<>(spell);
             spellId = spell.getUuid();
+            update();
+        }
+
+        void update() {
+            previousPos = currentPos;
+            currentPos = entity.getTarget().map(t -> BlockPos.ofFloored(t.pos())).orElse(BlockPos.ORIGIN);
+            if (!currentPos.equals(previousPos)) {
+                positionData.update(this);
+            }
         }
 
         public boolean hasChanged() {
@@ -216,6 +250,13 @@ public class Ether extends PersistentState {
             markDirty();
         }
 
+
+        @Override
+        public BlockPos getCenter() {
+            return currentPos;
+        }
+
+        @Override
         public float getRadius() {
             return radius;
         }
@@ -223,6 +264,9 @@ public class Ether extends PersistentState {
         public void setRadius(float radius) {
             if (!MathHelper.approximatelyEquals(this.radius, radius)) {
                 this.radius = radius;
+                if ((int)radius != (int)this.radius) {
+                    positionData.update(this);
+                }
                 changed.set(true);
             }
             markDirty();
@@ -247,6 +291,7 @@ public class Ether extends PersistentState {
         public void markDead() {
             Unicopia.LOGGER.debug("Marking " + entity.getTarget().orElse(null) + " as dead");
             removed = true;
+            positionData.remove(this);
             claimants.clear();
             markDirty();
         }

src/main/java/com/minelittlepony/unicopia/server/world/WorldOverlay.java

@@ -98,7 +98,7 @@ public class WorldOverlay<T extends WorldOverlay.State> extends PersistentState
     }
 
     private Chunk getChunk(BlockPos pos) {
-        return chunks.computeIfAbsent(new ChunkPos(pos).toLong(), Chunk::new);
+        return chunks.computeIfAbsent(ChunkPos.toLong(pos), Chunk::new);
     }
 
     public void setState(BlockPos pos, @Nullable T state) {

src/main/java/com/minelittlepony/unicopia/server/world/chunk/Chunk.java

@@ -0,0 +1,64 @@
+package com.minelittlepony.unicopia.server.world.chunk;
+
+import java.util.HashSet;
+import java.util.Map;
+import java.util.Set;
+import java.util.WeakHashMap;
+
+import it.unimi.dsi.fastutil.longs.Long2ObjectMap;
+import it.unimi.dsi.fastutil.longs.Long2ObjectOpenHashMap;
+import net.minecraft.util.math.BlockPos;
+import net.minecraft.util.math.Box;
+import net.minecraft.util.math.ChunkSectionPos;
+
+public class Chunk<T extends PositionalDataMap.Hotspot> {
+    private final Long2ObjectMap<Section<T>> sections = new Long2ObjectOpenHashMap<>();
+    private final Map<T, Set<Section<T>>> entryToSections = new WeakHashMap<>();
+
+    Chunk(long pos) { }
+
+    public synchronized Set<T> getState(BlockPos pos) {
+        Section<T> section = sections.get(ChunkSectionPos.getSectionCoord(pos.getY()));
+        return section == null ? Set.of() : section.getState(pos);
+    }
+
+    public synchronized boolean remove(T entry) {
+        Set<Section<T>> sections = entryToSections.remove(entry);
+        if (sections != null) {
+            sections.forEach(section -> {
+                if (section.remove(entry) && section.isEmpty()) {
+                    this.sections.remove(section.pos);
+                }
+            });
+            return true;
+        }
+        return false;
+    }
+
+    public synchronized boolean update(T entry, Box entryBox) {
+        Set<Section<T>> oldSections = entryToSections.get(entry);
+        Set<Section<T>> newSections = getIntersectingSections(entryBox);
+        if (oldSections != null) {
+            oldSections.forEach(section -> {
+                if (!newSections.contains(section) && section.remove(entry) && section.isEmpty()) {
+                    this.sections.remove(section.pos);
+                }
+            });
+        }
+        newSections.forEach(chunk -> chunk.update(entry, entryBox));
+        entryToSections.put(entry, newSections);
+        return true;
+    }
+
+    private Set<Section<T>> getIntersectingSections(Box entryBox) {
+        Set<Section<T>> sections = new HashSet<>();
+
+        int minY = ChunkSectionPos.getSectionCoord(entryBox.minY);
+        int maxY = ChunkSectionPos.getSectionCoord(entryBox.maxY);
+        for (int y = minY; y <= maxY; y++) {
+            sections.add(this.sections.computeIfAbsent(y, Section::new));
+        }
+
+        return sections;
+    }
+}

src/main/java/com/minelittlepony/unicopia/server/world/chunk/PositionalDataMap.java

@@ -0,0 +1,63 @@
+package com.minelittlepony.unicopia.server.world.chunk;
+
+import java.util.HashSet;
+import java.util.Map;
+import java.util.Set;
+import java.util.WeakHashMap;
+
+import it.unimi.dsi.fastutil.longs.Long2ObjectMap;
+import it.unimi.dsi.fastutil.longs.Long2ObjectOpenHashMap;
+import net.minecraft.util.math.BlockPos;
+import net.minecraft.util.math.Box;
+import net.minecraft.util.math.ChunkPos;
+import net.minecraft.util.math.ChunkSectionPos;
+import net.minecraft.util.math.MathHelper;
+
+public class PositionalDataMap<T extends PositionalDataMap.Hotspot> {
+    private final Long2ObjectMap<Chunk<T>> chunks = new Long2ObjectOpenHashMap<>();
+    private final Map<T, Set<Chunk<T>>> entryToChunks = new WeakHashMap<>();
+
+    public Set<T> getState(BlockPos pos) {
+        Chunk<T> chunk = chunks.get(ChunkPos.toLong(pos));
+        return chunk == null ? Set.of() : chunk.getState(pos);
+    }
+
+    public void remove(T entry) {
+        Set<Chunk<T>> chunks = entryToChunks.remove(entry);
+        if (chunks != null) {
+            chunks.forEach(chunk -> chunk.remove(entry));
+        }
+    }
+
+    public void update(T entry) {
+        Box entryBox = new Box(entry.getCenter()).expand(MathHelper.ceil(entry.getRadius()));
+        Set<Chunk<T>> oldChunks = entryToChunks.get(entry);
+        Set<Chunk<T>> newChunks = getIntersectingChunks(entryBox);
+        if (oldChunks != null) {
+            oldChunks.forEach(chunk -> chunk.remove(entry));
+        }
+        newChunks.forEach(chunk -> chunk.update(entry, entryBox));
+        entryToChunks.put(entry, newChunks);
+    }
+
+    private Set<Chunk<T>> getIntersectingChunks(Box entryBox) {
+        int minX = ChunkSectionPos.getSectionCoord(entryBox.minX);
+        int maxX = ChunkSectionPos.getSectionCoord(entryBox.maxX);
+        int minZ = ChunkSectionPos.getSectionCoord(entryBox.minZ);
+        int maxZ = ChunkSectionPos.getSectionCoord(entryBox.maxZ);
+
+        Set<Chunk<T>> chunks = new HashSet<>();
+        for (int x = minX; x <= maxX; x++) {
+            for (int z = minZ; z <= maxZ; z++) {
+                chunks.add(this.chunks.computeIfAbsent(ChunkPos.toLong(x, z), Chunk::new));
+            }
+        }
+        return chunks;
+    }
+
+    public interface Hotspot {
+        float getRadius();
+
+        BlockPos getCenter();
+    }
+}

src/main/java/com/minelittlepony/unicopia/server/world/chunk/Section.java

@@ -0,0 +1,82 @@
+package com.minelittlepony.unicopia.server.world.chunk;
+
+import java.util.Collections;
+import java.util.Set;
+import java.util.WeakHashMap;
+
+import net.minecraft.util.math.BlockPos;
+import net.minecraft.util.math.Box;
+import net.minecraft.util.math.MathHelper;
+
+public class Section<T extends PositionalDataMap.Hotspot> {
+    private final Set<T> entries = weakSet();
+    private Set<T>[] states;
+
+    final long pos;
+
+    public Section(long pos) {
+        this.pos = pos;
+    }
+
+    public boolean isEmpty() {
+        return entries.isEmpty();
+    }
+
+    public boolean remove(T entry) {
+        if (entries.remove(entry)) {
+            states = null;
+            return true;
+        }
+        return false;
+    }
+
+    public boolean update(T entry, Box box) {
+        entries.add(entry);
+        states = null;
+        return true;
+    }
+
+    @SuppressWarnings("unchecked")
+    public Set<T> getState(BlockPos pos) {
+        int localPos = toLocalIndex(pos);
+        if (states == null) {
+            states = new Set[16 * 16 * 16];
+        }
+        Set<T> state = states[localPos];
+        return state == null ? (states[localPos] = calculateState(pos)) : state;
+    }
+
+    private Set<T> calculateState(BlockPos pos) {
+        Set<T> state = weakSet();
+
+        for (T entry : entries) {
+            BlockPos center = entry.getCenter();
+            int radius = MathHelper.ceil(entry.getRadius());
+
+            if (pos.equals(center)
+                   || (isInRange(pos.getX(), center.getX(), radius)
+                    && isInRange(pos.getZ(), center.getZ(), radius)
+                    && isInRange(pos.getY(), center.getY(), radius)
+                    && center.isWithinDistance(pos, radius))) {
+                state.add(entry);
+            }
+        }
+
+        return state;
+    }
+
+    static boolean isInRange(int value, int center, int radius) {
+        return value >= center - radius && value <= center + radius;
+    }
+
+    static int toLocalIndex(BlockPos pos) {
+        int x = pos.getX() % 16;
+        int y = pos.getY() % 16;
+        int z = pos.getZ() % 16;
+        return x + (y * 16) + (z * 16 * 16);
+    }
+
+    static<T> Set<T> weakSet() {
+        return Collections.newSetFromMap(new WeakHashMap<>());
+    }
+}