Extra mod field parsing (untested)

core/src/mindustry/content/TechTree.java

@@ -15,6 +15,7 @@ import static mindustry.type.ItemStack.*;
 
 public class TechTree implements ContentList{
     static ObjectMap<UnlockableContent, TechNode> map = new ObjectMap<>();
+    static TechNode context = null;
 
     public static Seq<TechNode> all;
     public static TechNode root;
@@ -543,36 +544,46 @@ public class TechTree implements ContentList{
     }
 
     public static void setup(){
-        TechNode.context = null;
+        context = null;
         map = new ObjectMap<>();
         all = new Seq<>();
     }
 
-    public static TechNode node(UnlockableContent content, Runnable children){
+    //all the "node" methods are hidden, because they are for internal context-dependent use only
+    //for custom research, just use the TechNode constructor
+
+    static TechNode node(UnlockableContent content, Runnable children){
         return node(content, content.researchRequirements(), children);
     }
 
-    public static TechNode node(UnlockableContent content, ItemStack[] requirements, Runnable children){
-        return new TechNode(content, requirements, children);
+    static TechNode node(UnlockableContent content, ItemStack[] requirements, Runnable children){
+        return node(content, requirements, null, children);
     }
 
-    public static TechNode node(UnlockableContent content, Seq<Objective> objectives, Runnable children){
-        TechNode node = new TechNode(content, content.researchRequirements(), children);
-        node.objectives = objectives;
+    static TechNode node(UnlockableContent content, ItemStack[] requirements, Seq<Objective> objectives, Runnable children){
+        TechNode node = new TechNode(context, content, requirements);
+        if(objectives != null){
+            node.objectives = objectives;
+        }
+
+        TechNode prev = context;
+        context = node;
+        children.run();
+        context = prev;
+
         return node;
     }
 
-    public static TechNode node(UnlockableContent block){
+    static TechNode node(UnlockableContent content, Seq<Objective> objectives, Runnable children){
+        return node(content, content.researchRequirements(), objectives, children);
+    }
+
+    static TechNode node(UnlockableContent block){
         return node(block, () -> {});
     }
 
-    public static TechNode create(UnlockableContent parent, UnlockableContent block){
-        TechNode.context = all.find(t -> t.content == parent);
-        return node(block, () -> {});
-    }
-
-    public static @Nullable
-    TechNode get(UnlockableContent content){
+    @Nullable
+    public static TechNode get(UnlockableContent content){
         return map.get(content);
     }
 
@@ -581,8 +592,6 @@ public class TechTree implements ContentList{
     }
 
     public static class TechNode{
-        static TechNode context;
-
         /** Depth in tech tree. */
         public int depth;
         /** Requirement node. */
@@ -600,10 +609,10 @@ public class TechTree implements ContentList{
         /** Nodes that depend on this node. */
         public final Seq<TechNode> children = new Seq<>();
 
-        TechNode(@Nullable TechNode ccontext, UnlockableContent content, ItemStack[] requirements, Runnable children){
-            if(ccontext != null) ccontext.children.add(this);
+        public TechNode(@Nullable TechNode parent, UnlockableContent content, ItemStack[] requirements){
+            if(parent != null) parent.children.add(this);
 
-            this.parent = ccontext;
+            this.parent = parent;
             this.content = content;
             this.requirements = requirements;
             this.depth = parent == null ? 0 : parent.depth + 1;
@@ -619,14 +628,15 @@ public class TechTree implements ContentList{
             content.getDependencies(d -> objectives.add(new Research(d)));
 
             map.put(content, this);
-            context = this;
-            children.run();
-            context = ccontext;
             all.add(this);
         }
 
-        TechNode(UnlockableContent content, ItemStack[] requirements, Runnable children){
-            this(context, content, requirements, children);
+        /** Removes this node from the tech tree. */
+        public void remove(){
+            all.remove(this);
+            if(parent != null){
+                parent.children.remove(this);
+            }
         }
 
         /** Flushes research progress to settings. */