feat: QuadTree

packages/math/index.js

@@ -1,5 +1,7 @@
 // export * as Matrix from './matrix';
 
+export {QuadTree} from './quadtree';
+
 import * as Rectangle from './rectangle';
 export {Rectangle};
 

packages/math/package.json

@@ -1,7 +1,10 @@
 {
   "name": "@avocado/math",
-  "version": "1.0.0",
+  "version": "1.0.1",
   "main": "index.js",
   "author": "cha0s",
-  "license": "MIT"
+  "license": "MIT",
+  "dependencies": {
+    "d3-quadtree": "1.0.6"
+  }
 }

packages/math/quadtree.js

@@ -0,0 +1,36 @@
+import {quadtree} from 'd3-quadtree';
+
+import * as Rectangle from './rectangle';
+
+export class QuadTree {
+
+  constructor() {
+    this.quadTree = quadtree();
+  }
+
+  add(datum) {
+    this.quadTree.add(datum);
+  }
+
+  remove(datum) {
+    this.quadTree.remove(datum);
+  }
+
+  search(queryRectangle) {
+    const nodes = [];
+    this.quadTree.visit((node, ...nodeRectangle) => {
+      nodeRectangle[2] -= nodeRectangle[0];
+      nodeRectangle[3] -= nodeRectangle[1];
+      if (!Rectangle.intersects(queryRectangle, nodeRectangle)) {
+        return true;
+      }
+      if (4 !== node.length) {
+        nodes.push(node);
+      }
+    });
+    return nodes.filter((node) => {
+      return Rectangle.isTouching(queryRectangle, node.data);
+    });
+  }
+
+}