Fix buildings disappearing when removing and re-adding nodes

Author: object-Object

mindy-website/www/src/components/AddBuildingMenu.tsx

@@ -11,7 +11,11 @@ import {
     ProcessorKind,
 } from "mindy-website";
 
-import { createNode } from "../utils";
+import {
+    createNode,
+    getMonotonicNodeCount,
+    incrementMonotonicNodeCount,
+} from "../utils";
 import type { LogicVMNode } from "./LogicVMFlow";
 
 export default function AddBuildingMenu() {
@@ -39,7 +43,7 @@ export default function AddBuildingMenu() {
         // calculate a position such that all nodes of a given size are at the same y position without overlapping
         const buildingPosition = {
             // leave enough room to the left assuming all nodes are in the same row as this one
-            x: reactFlow.getNodes().length * node.size,
+            x: getMonotonicNodeCount() * node.size,
             // the sum of the first n natural numbers is n*(n+1)/2
             // for a given size, we need to leave room below for all sizes < size
             // so y should be the sum of all sizes < size
@@ -48,6 +52,8 @@ export default function AddBuildingMenu() {
             y: ((node.size - 1) * node.size) / 2,
         };
 
+        incrementMonotonicNodeCount();
+
         return [
             createNode({
                 ...node,

mindy-website/www/src/components/LogicVMFlow.tsx

@@ -16,7 +16,7 @@ import { useCallback, useEffect } from "react";
 import { DisplayKind, ProcessorKind } from "mindy-website";
 
 import { useLogicVM } from "../hooks";
-import { createNode } from "../utils";
+import { createNode, setMonotonicNodeCount } from "../utils";
 import AddBuildingMenu from "./AddBuildingMenu";
 import BuildingLinkConnectionLine from "./edges/BuildingLinkConnectionLine";
 import BuildingLinkEdge from "./edges/BuildingLinkEdge";
@@ -92,6 +92,8 @@ const defaultEdges: Edge[] = [
     },
 ];
 
+setMonotonicNodeCount(defaultNodes.length);
+
 export default function LogicVMFlow() {
     const vm = useLogicVM();
 

mindy-website/www/src/utils.ts

@@ -98,3 +98,17 @@ export function createNode<N, D>(
         },
     };
 }
+
+let monotonicNodeCount = 0;
+
+export function getMonotonicNodeCount() {
+    return monotonicNodeCount;
+}
+
+export function setMonotonicNodeCount(n: number) {
+    monotonicNodeCount = Math.max(n, monotonicNodeCount);
+}
+
+export function incrementMonotonicNodeCount() {
+    setMonotonicNodeCount(monotonicNodeCount + 1);
+}