Implement mutual exclusives

src/main/java/net/fretux/skillengine/skilltree/SkillLogic.java

@@ -17,6 +17,11 @@ public class SkillLogic {
         for (ResourceLocation neighborId : node.getLinks()) {
             if (data.isUnlocked(neighborId)) return true;
         }
+        for (ResourceLocation excl : node.getExclusiveWith()) {
+            if (data.isUnlocked(excl)) {
+                return false;
+            }
+        }
         return false;
     }
     public static boolean meetsAscendPrerequisites(Player player, SkillNode node) {

src/main/java/net/fretux/skillengine/skilltree/SkillNode.java

@@ -18,6 +18,7 @@ public class SkillNode {
     private final List<ResourceLocation> tags;
     private final ResourceLocation icons;
     private final Map<String, Integer> prereqAttributes;
+    private final List<ResourceLocation> exclusiveWith;
 
     public SkillNode(ResourceLocation id,
                      Component title,
@@ -27,7 +28,8 @@ public class SkillNode {
                      List<ResourceLocation> links,
                      List<ResourceLocation> tags,
                      ResourceLocation icons,
-                     Map<String, Integer> prereqAttributes) {
+                     Map<String, Integer> prereqAttributes,
+                     List<ResourceLocation> exclusiveWith){
 
         this.id = id;
         this.title = title;
@@ -39,6 +41,7 @@ public class SkillNode {
         this.tags = List.copyOf(tags);
         this.icons = icons;
         this.prereqAttributes = Map.copyOf(prereqAttributes);
+        this.exclusiveWith = List.copyOf(exclusiveWith);
     }
 
     public ResourceLocation getId() {
@@ -81,6 +84,10 @@ public class SkillNode {
         return prereqAttributes;
     }
 
+    public List<ResourceLocation> getExclusiveWith() {
+        return exclusiveWith;
+    }
+
     public boolean isRoot() {
         return links.isEmpty();
     }

src/main/java/net/fretux/skillengine/skilltree/SkillNodeLoader.java

@@ -61,6 +61,11 @@ public class SkillNodeLoader extends SimpleJsonResourceReloadListener {
                     prereqAttributes.put(entry.getKey(), entry.getValue().getAsInt());
                 }
             }
+            List<ResourceLocation> exclusiveWith = new ArrayList<>();
+            if (obj.has("exclusive_with")) {
+                obj.getAsJsonArray("exclusive_with").forEach(e ->
+                        exclusiveWith.add(new ResourceLocation(e.getAsString())));
+            }
             SkillNode node = new SkillNode(
                     nodeId,
                     Component.literal(title),
@@ -70,8 +75,10 @@ public class SkillNodeLoader extends SimpleJsonResourceReloadListener {
                     links,
                     tags,
                     icons,
-                    prereqAttributes
+                    prereqAttributes,
+                    exclusiveWith
             );
+
             SkillNodeRegistry.put(node);
         });
         SkillEngine.LOGGER.info("Loaded {} skill nodes", SkillNodeRegistry.all().size());