From a258f0dfc3bf6227fe66ec3b642870c2526d6f58 Mon Sep 17 00:00:00 2001
From: Mark Tolmacs <mark@lazycat.hu>
Date: Tue, 11 Feb 2025 15:07:03 +0100
Subject: [PATCH] Remove arrow tangent vector util

---
 packages/excalidraw/scene/Shape.ts | 92 +-----------------------------
 1 file changed, 3 insertions(+), 89 deletions(-)

diff --git a/packages/excalidraw/scene/Shape.ts b/packages/excalidraw/scene/Shape.ts
index 63b57620b4..ba55b2f606 100644
--- a/packages/excalidraw/scene/Shape.ts
+++ b/packages/excalidraw/scene/Shape.ts
@@ -1,6 +1,6 @@
 import type { Point as RoughPoint } from "roughjs/bin/geometry";
 import type { Drawable, Options } from "roughjs/bin/core";
-import { RoughGenerator } from "roughjs/bin/generator";
+import type { RoughGenerator } from "roughjs/bin/generator";
 import { getDiamondPoints, getArrowheadPoints } from "../element";
 import type { ElementShapes } from "./types";
 import type {
@@ -11,7 +11,7 @@ import type {
   Arrowhead,
 } from "../element/types";
 import { generateFreeDrawShape } from "../renderer/renderElement";
-import { isTransparent, assertNever, invariant } from "../utils";
+import { isTransparent, assertNever } from "../utils";
 import { simplify } from "points-on-curve";
 import { ROUGHNESS } from "../constants";
 import {
@@ -23,15 +23,9 @@ import {
 } from "../element/typeChecks";
 import { canChangeRoundness } from "./comparisons";
 import type { EmbedsValidationStatus } from "../types";
-import {
-  pointFrom,
-  pointDistance,
-  type LocalPoint,
-  vectorFromPoint,
-} from "../../math";
+import { pointFrom, pointDistance, type LocalPoint } from "../../math";
 import { getCornerRadius, isPathALoop } from "../shapes";
 import { headingForPointIsHorizontal } from "../element/heading";
-import { COLOR_PALETTE } from "../colors";
 
 const getDashArrayDashed = (strokeWidth: number) => [8, 8 + strokeWidth];
 
@@ -593,83 +587,3 @@ const generateElbowArrowShape = (
 
   return d.join(" ");
 };
-
-/**
- * In order to precisely determine the binding point even for rough rounded linear elements,
- * we need to calculate the tangent vector at the start or end of the linear element from the
- * render shape itself (not the start/end points).
- *
- * @param linearElement The linear element to determine the endpoint tangent vector for
- * @param startOrEnd Specify 'start' or 'end' to determine which endpoint tangent you need
- * @returns The tangent vector
- */
-export const getLinearElementTangentVectorAtStartOrEnd = (
-  linearElement: ExcalidrawLinearElement,
-  startOrEnd: "start" | "end",
-) => {
-  import.meta.env.DEV &&
-    invariant(
-      linearElement.points.length > 1,
-      "line must have at least 2 points to determine tangent vector",
-    );
-
-  if (linearElement.roundness == null || isElbowArrow(linearElement)) {
-    return vectorFromPoint(
-      linearElement.points[
-        startOrEnd === "start" ? 0 : linearElement.points.length - 1
-      ],
-      linearElement.points[
-        startOrEnd === "start" ? 1 : linearElement.points.length - 2
-      ],
-    );
-  }
-
-  // NOTE: Using _generateElementShape to not pollute the shape cache with fake
-  // shapes that are only used for determining the tangent vector
-  const shapes =
-    linearElement.roughness > 0
-      ? _generateElementShape(
-          {
-            ...linearElement,
-            roughness: 0, // We need the exact linear shape, not a rough shape
-          },
-          new RoughGenerator(),
-          {
-            isExporting: false,
-            canvasBackgroundColor: COLOR_PALETTE.white,
-            embedsValidationStatus: null,
-          },
-        )
-      : _generateElementShape(linearElement, new RoughGenerator(), {
-          isExporting: false,
-          canvasBackgroundColor: COLOR_PALETTE.white,
-          embedsValidationStatus: null,
-        });
-
-  import.meta.env.DEV &&
-    invariant(
-      shapes != null &&
-        Array.isArray(shapes) &&
-        shapes.length > 0 &&
-        shapes[0].shape === "curve" &&
-        shapes[0].sets[0] &&
-        shapes[0].sets[0].type === "path",
-      "shape must be an array of Drawable with at least one shape",
-    );
-  // @ts-ignore
-  const ops = shapes[0].sets[0].ops;
-  const bcurve = ops[startOrEnd === "start" ? 1 : ops.length - 1];
-
-  import.meta.env.DEV &&
-    invariant(bcurve.op === "bcurveTo", "selected op must be a bcurve");
-
-  return startOrEnd === "start"
-    ? vectorFromPoint(
-        pointFrom<LocalPoint>(0, 0),
-        pointFrom<LocalPoint>(bcurve.data[2], bcurve.data[3]),
-      )
-    : vectorFromPoint(
-        pointFrom<LocalPoint>(bcurve.data[2], bcurve.data[3]),
-        pointFrom<LocalPoint>(bcurve.data[4], bcurve.data[5]),
-      );
-};