From 689173c08f5353cee3070323628e02534b76a109 Mon Sep 17 00:00:00 2001
From: Jazza-231 <greeny-231@outlook.com>
Date: Mon, 8 Jan 2024 14:25:49 +0800
Subject: [PATCH] initial commmit

---
 addons/addons.json                |  1 +
 addons/anchor-point/addon.json    | 18 +++++++
 addons/anchor-point/userscript.js | 79 +++++++++++++++++++++++++++++++
 3 files changed, 98 insertions(+)
 create mode 100644 addons/anchor-point/addon.json
 create mode 100644 addons/anchor-point/userscript.js

diff --git a/addons/addons.json b/addons/addons.json
index e8cefbc313..6daf4650dd 100644
--- a/addons/addons.json
+++ b/addons/addons.json
@@ -150,6 +150,7 @@
   "paint-skew",
   "preview-project-description",
   "collapse-footer",
+  "anchor-point",
 
   "// NEW ADDONS ABOVE THIS ↑↑",
   "// Note: these themes need this exact order to work properly,",
diff --git a/addons/anchor-point/addon.json b/addons/anchor-point/addon.json
new file mode 100644
index 0000000000..6664ee27c9
--- /dev/null
+++ b/addons/anchor-point/addon.json
@@ -0,0 +1,18 @@
+{
+  "name": "Shiftable anchor point",
+  "description": "Allows you to rotate the selection around a point other than the center.",
+  "credits": [
+    {
+      "name": "Jazza",
+      "link": "https://scratch.mit.edu/users/greeny--231"
+    }
+  ],
+  "userscripts": [
+    {
+      "url": "userscript.js",
+      "matches": ["projects"]
+    }
+  ],
+  "tags": ["editor", "costumeEditor", "featured", "recommended"],
+  "versionAdded": "1.35.0"
+}
diff --git a/addons/anchor-point/userscript.js b/addons/anchor-point/userscript.js
new file mode 100644
index 0000000000..119c2c743c
--- /dev/null
+++ b/addons/anchor-point/userscript.js
@@ -0,0 +1,79 @@
+import { loadModules } from "../paint-snap/helpers.js";
+
+export default async function ({ addon, console }) {
+  window.addon = addon;
+  const paper = await addon.tab.traps.getPaper();
+
+  /**
+   * Selection must be a single item or a group
+   * When you have something selected, a custom pivot point will show, and when you drag it,
+   * that is the point on the canvas which it rotates around (you can not rotate relative to the
+   * item, because its center changes on rotation).
+   * When you move the item/group, the pivot point is moved too, so that it's not rotating on the same canvas point, but
+   * acts like it is relative to the item.
+   * Make sure to keep all original scratch features (shift to snap to 45 degrees), and think about compat with new addon idea
+   * customising the value that it snaps to when you hold shift.
+   * Add an option to lock it the canvas no matter where you move the object - hexagonal
+   * Pivot point, when dragged, snaps to the center of the object
+   */
+
+  // updateSelectTool.js line 114 is the selection anchor, this should be made draggable and displays new pivot point
+  // Snapping addon snaps from pivot point, not center.
+
+  // Local storage structure (don't forget localStorage only allows strings, use JSON.stringify)
+  // In order to do .clone() etc on the pivots, after reading, use new paper.Point([x, y])
+  const data = [
+    {
+      spriteId: "|f}2;)JrF-0wS)ZPxtgL",
+      costumeId: "592bae6f8bb9c8d88401b54ac431f7b6",
+      itemId: 10,
+      pivot: {
+        x: 530,
+        y: 310,
+      },
+      locked: true, // If locked is false, pivot is changed when dragged
+      // (IMPORTANT: you cant do anything relative to the object, you just have to pretend it is)
+    },
+  ];
+
+  const {
+    layer: { getLayer },
+  } = loadModules(paper);
+
+  const rotateTool = paper.tool.boundingBoxTool._modeMap.ROTATE;
+
+  rotateTool.constructor.prototype.onMouseDrag = function (e) {
+    // rotGroupPivot gets set to null on mouse up, thus the changed property is falsy
+    // Do it this way so that we don't have to worry about changing the onMouseDown function
+    if (!this.rotGroupPivot.changed) {
+      this.realPivot = this.rotGroupPivot.clone();
+      this.rotGroupPivot.x = data[0].pivot.x;
+      this.rotGroupPivot.y = data[0].pivot.y;
+      this.rotGroupPivot.changed = true;
+
+      let v1 = e.point.subtract(this.rotGroupPivot);
+      let v2 = e.point.subtract(this.realPivot);
+      let angle = Math.acos(v1.dot(v2) / (v1.length * v2.length)) * (180 / Math.PI);
+      angle *= e.point.x < this.rotGroupPivot.x ? -1 : 1;
+      this.modifierAngle = angle;
+    }
+
+    let rotAngle = e.point.subtract(this.rotGroupPivot).angle + this.modifierAngle;
+    if (e.modifiers.shift) {
+      rotAngle = Math.round(rotAngle / 45) * 45;
+    }
+
+    this.rotItems.forEach((item) => {
+      item.rotate(rotAngle - this.prevRot, this.rotGroupPivot);
+    });
+
+    this.prevRot = rotAngle;
+  };
+
+  const oldSetSelectionBounds = paper.tool.boundingBoxTool.setSelectionBounds;
+  paper.tool.boundingBoxTool.setSelectionBounds = function () {
+    oldSetSelectionBounds.call(this);
+
+    this.boundsPath.selectionAnchor.position = new paper.Point(data[0].pivot);
+  };
+}