Faster entity removal

annotations/src/main/java/mindustry/annotations/entity/EntityProcess.java

@@ -232,9 +232,15 @@ public class EntityProcess extends BaseProcessor{
                 Stype repr = types.first();
                 String groupType = repr.annotation(Component.class).base() ? baseName(repr) : interfaceName(repr);
 
+                String name = group.name().startsWith("g") ? group.name().substring(1) : group.name();
+
                 boolean collides = an.collide();
-                groupDefs.add(new GroupDefinition(group.name().startsWith("g") ? group.name().substring(1) : group.name(),
+                groupDefs.add(new GroupDefinition(name,
                     ClassName.bestGuess(packageName + "." + groupType), types, an.spatial(), an.mapping(), collides));
+
+                TypeSpec.Builder accessor = TypeSpec.interfaceBuilder("IndexableEntity__" + name);
+                accessor.addMethod(MethodSpec.methodBuilder("setIndex__" + name).addModifiers(Modifier.ABSTRACT, Modifier.PUBLIC).addParameter(int.class, "index").returns(void.class).build());
+                write(accessor);
             }
 
             ObjectMap<String, Selement> usedNames = new ObjectMap<>();
@@ -394,6 +400,13 @@ public class EntityProcess extends BaseProcessor{
                 //entities with no sync comp and no serialization gen no code
                 boolean hasIO = ann.genio() && (components.contains(s -> s.name().contains("Sync")) || ann.serialize());
 
+                //implement indexable interfaces.
+                for(GroupDefinition def : groups){
+                    builder.addSuperinterface(tname(packageName + ".IndexableEntity__" + def.name));
+                    builder.addMethod(MethodSpec.methodBuilder("setIndex__" + def.name).addParameter(int.class, "index").addModifiers(Modifier.PUBLIC).addAnnotation(Override.class)
+                    .addCode("index__$L = index;", def.name).build());
+                }
+
                 //add all methods from components
                 for(ObjectMap.Entry<String, Seq<Smethod>> entry : methods){
                     if(entry.value.contains(m -> m.has(Replace.class))){
@@ -446,8 +459,15 @@ public class EntityProcess extends BaseProcessor{
                         mbuilder.addStatement("if(added == $L) return", first.name().equals("add"));
 
                         for(GroupDefinition def : groups){
+                            if(first.name().equals("add")){
                                 //remove/add from each group, assume imported
-                            mbuilder.addStatement("Groups.$L.$L(this)", def.name, first.name());
+                                mbuilder.addStatement("index__$L = Groups.$L.addIndex(this)", def.name, def.name);
+                            }else{
+                                //remove/add from each group, assume imported
+                                mbuilder.addStatement("Groups.$L.removeIndex(this, index__$L);", def.name, def.name);
+
+                                mbuilder.addStatement("index__$L = -1", def.name);
+                            }
                         }
                     }
 
@@ -577,6 +597,13 @@ public class EntityProcess extends BaseProcessor{
 
                 skipDeprecated(builder);
 
+                if(!legacy){
+                    //add group index int variables
+                    for(GroupDefinition def : groups){
+                        builder.addField(FieldSpec.builder(int.class, "index__" + def.name, Modifier.PROTECTED).initializer("-1").build());
+                    }
+                }
+
                 definitions.add(new EntityDefinition(packageName + "." + name, builder, type, typeIsBase ? null : baseClass, components, groups, allFieldSpecs, legacy));
             }
 
@@ -592,7 +619,7 @@ public class EntityProcess extends BaseProcessor{
                 groupsBuilder.addField(ParameterizedTypeName.get(
                     ClassName.bestGuess("mindustry.entities.EntityGroup"), itype), group.name, Modifier.PUBLIC, Modifier.STATIC);
 
-                groupInit.addStatement("$L = new $T<>($L.class, $L, $L)", group.name, groupc, itype, group.spatial, group.mapping);
+                groupInit.addStatement("$L = new $T<>($L.class, $L, $L, (e, pos) -> (($L.IndexableEntity__$L)e).setIndex__$L(pos))", group.name, groupc, itype, group.spatial, group.mapping, packageName, group.name, group.name);
             }
 
             //write the groups

core/src/mindustry/entities/EntityGroup.java

@@ -20,6 +20,7 @@ public class EntityGroup<T extends Entityc> implements Iterable<T>{
     private final Seq<T> intersectArray = new Seq<>();
     private final Rect viewport = new Rect();
     private final Rect intersectRect = new Rect();
+    private final EntityIndexer indexer;
     private IntMap<T> map;
     private QuadTree tree;
     private boolean clearing;
@@ -36,6 +37,10 @@ public class EntityGroup<T extends Entityc> implements Iterable<T>{
     }
 
     public EntityGroup(Class<T> type, boolean spatial, boolean mapping){
+        this(type, spatial, mapping, null);
+    }
+
+    public EntityGroup(Class<T> type, boolean spatial, boolean mapping, EntityIndexer indexer){
         array = new Seq<>(false, 32, type);
 
         if(spatial){
@@ -45,6 +50,8 @@ public class EntityGroup<T extends Entityc> implements Iterable<T>{
         if(mapping){
             map = new IntMap<>();
         }
+
+        this.indexer = indexer;
     }
 
     /** @return entities with colliding IDs, or an empty array. */
@@ -107,7 +114,7 @@ public class EntityGroup<T extends Entityc> implements Iterable<T>{
     }
 
     public boolean useTree(){
-        return map != null;
+        return tree != null;
     }
 
     public boolean mappingEnabled(){
@@ -183,12 +190,25 @@ public class EntityGroup<T extends Entityc> implements Iterable<T>{
         }
     }
 
+    public int addIndex(T type){
+        int index = array.size;
+        add(type);
+        return index;
+    }
+
     public void remove(T type){
         if(clearing) return;
         if(type == null) throw new RuntimeException("Cannot remove a null entity!");
         int idx = array.indexOf(type, true);
         if(idx != -1){
             array.remove(idx);
+
+            //fix incorrect HEAD index since it was swapped
+            if(array.size > 0 && idx != array.size){
+                var swapped = array.items[idx];
+                indexer.change(swapped, idx);
+            }
+
             if(map != null){
                 map.remove(type.id());
             }
@@ -200,6 +220,32 @@ public class EntityGroup<T extends Entityc> implements Iterable<T>{
         }
     }
 
+    public void removeIndex(T type, int position){
+        if(clearing) return;
+        if(type == null) throw new RuntimeException("Cannot remove a null entity!");
+        if(position != -1 && position < array.size){
+
+            //swap head with current
+            if(array.size > 1){
+                var head = array.items[array.size - 1];
+                indexer.change(head, position);
+                array.items[position] = head;
+            }
+
+            array.size --;
+            array.items[array.size] = null;
+
+            if(map != null){
+                map.remove(type.id());
+            }
+
+            //fix iteration index when removing
+            if(index >= position){
+                index --;
+            }
+        }
+    }
+
     public void clear(){
         clearing = true;
 

core/src/mindustry/entities/EntityIndexer.java

@@ -0,0 +1,7 @@
+package mindustry.entities;
+
+import mindustry.gen.*;
+
+public interface EntityIndexer{
+    void change(Entityc t, int index);
+}

core/src/mindustry/world/blocks/logic/CanvasBlock.java

@@ -137,6 +137,12 @@ public class CanvasBlock extends Block{
 
         @Override
         public void draw(){
+            if(!renderer.drawDisplays){
+                super.draw();
+
+                return;
+            }
+
             if(blending == 0){
                 super.draw();
             }