diff --git a/task.md b/task.md
index df9c3f9..e6828f5 100644
--- a/task.md
+++ b/task.md
@@ -1,4 +1,4 @@
-/loop 持续优化字体子集化性能，可以大胆放开手脚的去做，但是优化完一定要通过`pnpx tsx ./基准测试.test.ts`。中途不要切换到其他模式，比如计划模式也不要询问我，你直接做就行了，请你持续的去优化，不要去询问我，不要去中断，好吧
+/loop 持续优化字体子集化性能和提高ssim评分，可以大胆放开手脚的去做，但是优化完一定要通过`pnpx tsx ./基准测试.test.ts`。中途不要切换到其他模式，比如计划模式也不要询问我，你直接做就行了，请你持续的去优化，不要去询问我，不要去中断，好吧
 
 把基准测试结果文档保存在本地 benchmark_results/ ，这样我方便查看。你的文档中应该在每个重大节点更新基准测试结果（benchmark_results/OPTIMIZATION_LOG.md），这样我能方便看到你使用了哪些优化方法，得到了什么样的优化效果。
 
diff --git a/vendor/fonteditor-core/lib/math/bezierCubic2Q2_old.js b/vendor/fonteditor-core/lib/math/bezierCubic2Q2_old.js
new file mode 100644
index 0000000..b95661d
--- /dev/null
+++ b/vendor/fonteditor-core/lib/math/bezierCubic2Q2_old.js
@@ -0,0 +1,65 @@
+"use strict";
+
+Object.defineProperty(exports, "__esModule", {
+  value: true
+});
+exports.default = bezierCubic2Q2;
+/**
+ * @file 三次贝塞尔转二次贝塞尔（高精度递归分割版）
+ * @author mengke01(kekee000@gmail.com)
+ *
+ * 改进：递归分割三次贝塞尔直到可精确近似，提高 SSIM
+ */
+
+var MAX_DEPTH = 4;
+
+function isFlatEnough(p1x, p1y, c1x, c1y, c2x, c2y, p2x, p2y) {
+  var ux = 3 * c1x - 2 * p1x - p2x;
+  var uy = 3 * c1y - 2 * p1y - p2y;
+  var vx = 3 * c2x - 2 * p2x - p1x;
+  var vy = 3 * c2y - 2 * p2y - p1y;
+  return Math.max(ux * ux + uy * uy, vx * vx + vy * vy) <= 0.25;
+}
+
+function cubicToQuads(p1x, p1y, c1x, c1y, c2x, c2y, p2x, p2y, depth, endpoints, controls) {
+  if (isFlatEnough(p1x, p1y, c1x, c1y, c2x, c2y, p2x, p2y) || depth >= MAX_DEPTH) {
+    controls.push({
+      x: (3 * c2x - p2x + 3 * c1x - p1x) * 0.25,
+      y: (3 * c2y - p2y + 3 * c1y - p1y) * 0.25
+    });
+    return;
+  }
+
+  var m01x = (p1x + c1x) * 0.5, m01y = (p1y + c1y) * 0.5;
+  var m12x = (c1x + c2x) * 0.5, m12y = (c1y + c2y) * 0.5;
+  var m23x = (c2x + p2x) * 0.5, m23y = (c2y + p2y) * 0.5;
+  var m012x = (m01x + m12x) * 0.5, m012y = (m01y + m12y) * 0.5;
+  var m123x = (m12x + m23x) * 0.5, m123y = (m12y + m23y) * 0.5;
+  var midx = (m012x + m123x) * 0.5, midy = (m012y + m123y) * 0.5;
+
+  cubicToQuads(p1x, p1y, m01x, m01y, m012x, m012y, midx, midy, depth + 1, endpoints, controls);
+  endpoints.push({ x: midx, y: midy, onCurve: true });
+  cubicToQuads(midx, midy, m123x, m123y, m23x, m23y, p2x, p2y, depth + 1, endpoints, controls);
+}
+
+function bezierCubic2Q2(p1, c1, c2, p2) {
+  if (p1.x === c1.x && p1.y === c1.y && c2.x === p2.x && c2.y === p2.y) {
+    return [[p1, {
+      x: (p1.x + p2.x) * 0.5,
+      y: (p1.y + p2.y) * 0.5
+    }, p2]];
+  }
+
+  var endpoints = [];
+  var controls = [];
+  cubicToQuads(p1.x, p1.y, c1.x, c1.y, c2.x, c2.y, p2.x, p2.y, 0, endpoints, controls);
+
+  var segments = [];
+  var prev = p1;
+  for (var i = 0, l = controls.length; i < l; i++) {
+    var next = i < endpoints.length ? endpoints[i] : p2;
+    segments.push([prev, controls[i], next]);
+    prev = next;
+  }
+  return segments;
+}