fix: Arrow overlap arrow behavior (#10732)

* fix(arrow): Overlap arrow behavior

Signed-off-by: Mark Tolmacs <mark@lazycat.hu>

* fix: Lint

Signed-off-by: Mark Tolmacs <mark@lazycat.hu>

* feat(editor): reduce binding gap (#10739)

* feat(editor): reduce binding gap to 7px

* feat(editor): reduce binding gap to 5px

* feat(editor): reduce binding gap to 3px

* go back to 5px

* update tests

* feat: Simplified update bind points

Signed-off-by: Mark Tolmacs <mark@lazycat.hu>

* fix: Remove non-needed export

Signed-off-by: Mark Tolmacs <mark@lazycat.hu>

* fix. Possessed arrows #1

Signed-off-by: Mark Tolmacs <mark@lazycat.hu>

* fix: Focus point projection stabilization

Signed-off-by: Mark Tolmacs <mark@lazycat.hu>

* fix: Remove arrow stability hack

Signed-off-by: Mark Tolmacs <mark@lazycat.hu>

* fix: Unbound other endpoint

Signed-off-by: Mark Tolmacs <mark@lazycat.hu>

* feat(editor): visualize binding midpoints + support for simple arrows (#10611)

* feat: Force exact center focus point

When the projected point is close to center snap it to the exact center.

Signed-off-by: Mark Tolmacs <mark@lazycat.hu>

* fix: Tests

Signed-off-by: Mark Tolmacs <mark@lazycat.hu>

* fix: Snap to center around side mid point.

Signed-off-by: Mark Tolmacs <mark@lazycat.hu>

* Trigger CI

* fix: Midpoint outline focus point

Signed-off-by: Mark Tolmacs <mark@lazycat.hu>

* fix: Tests

Signed-off-by: Mark Tolmacs <mark@lazycat.hu>

* fix: Dragging existing arrow reset focus point on outline

Signed-off-by: Mark Tolmacs <mark@lazycat.hu>

* fix: Tests

Signed-off-by: Mark Tolmacs <mark@lazycat.hu>

* feat: Midpoint indicator

Signed-off-by: Mark Tolmacs <mark@lazycat.hu>

* fix: Rotated mid points

Signed-off-by: Mark Tolmacs <mark@lazycat.hu>

* fix: No hole

Signed-off-by: Mark Tolmacs <mark@lazycat.hu>

* feat: Cache hits and scene lookups

Signed-off-by: Mark Tolmacs <mark@lazycat.hu>

* chore: Remove debug

Signed-off-by: Mark Tolmacs <mark@lazycat.hu>

* fix: Consider hit threshold and inside override too

Signed-off-by: Mark Tolmacs <mark@lazycat.hu>

* fix: Increase outline midpoint sticky distance

Signed-off-by: Mark Tolmacs <mark@lazycat.hu>

* fix: Don't show midpoint indicator when no snapping is possible

Signed-off-by: Mark Tolmacs <mark@lazycat.hu>

* feat: Indicate lock-in

Signed-off-by: Mark Tolmacs <mark@lazycat.hu>

* chore: Remove Map caching

Signed-off-by: Mark Tolmacs <mark@lazycat.hu>

* fix: incorrect threshold

Signed-off-by: Mark Tolmacs <mark@lazycat.hu>

* fix: threshold setting

Signed-off-by: Mark Tolmacs <mark@lazycat.hu>

* fix: Hit caching

Signed-off-by: Mark Tolmacs <mark@lazycat.hu>

* fix: Simple arrow mid point selection inconsistency

Signed-off-by: Mark Tolmacs <mark@lazycat.hu>

* fix: cache override

Signed-off-by: Mark Tolmacs <mark@lazycat.hu>

* fix: Precise know dragging with midpoint refactor

Signed-off-by: Mark Tolmacs <mark@lazycat.hu>

* fear: Frame support

Signed-off-by: Mark Tolmacs <mark@lazycat.hu>

* fix: Crossing arrow won't trigger mid point

Signed-off-by: Mark Tolmacs <mark@lazycat.hu>

* fix: Arrow creation point highlight

Signed-off-by: Mark Tolmacs <mark@lazycat.hu>

* fix: Restore types & tests

Signed-off-by: Mark Tolmacs <mark@lazycat.hu>

* chore: Restore restore.ts

Signed-off-by: Mark Tolmacs <mark@lazycat.hu>

* fix: restore.ts

Signed-off-by: Mark Tolmacs <mark@lazycat.hu>

* fix: Elbow arrows reliably highlight center point

Signed-off-by: Mark Tolmacs <mark@lazycat.hu>

* fix: Highlight point ordering

Signed-off-by: Mark Tolmacs <mark@lazycat.hu>

* feat: Bind with focus point across shape

Signed-off-by: Mark Tolmacs <mark@lazycat.hu>

* fix: Lint

* fix: Midpoint and binding alignment

Signed-off-by: Mark Tolmacs <mark@lazycat.hu>

* chore: Indicator color

Signed-off-by: Mark Tolmacs <mark@lazycat.hu>

* chore: More knob tuning

Signed-off-by: Mark Tolmacs <mark@lazycat.hu>

* fix: Radius

Signed-off-by: Mark Tolmacs <mark@lazycat.hu>

* fix: Tests

Signed-off-by: Mark Tolmacs <mark@lazycat.hu>

* simplify point indicators

---------

Signed-off-by: Mark Tolmacs <mark@lazycat.hu>
Co-authored-by: dwelle <5153846+dwelle@users.noreply.github.com>

* fix: Tests

Signed-off-by: Mark Tolmacs <mark@lazycat.hu>

* fix: Snapshots

Signed-off-by: Mark Tolmacs <mark@lazycat.hu>

* fix: Target point selection

Signed-off-by: Mark Tolmacs <mark@lazycat.hu>

* chore: Remove non-needed change

Signed-off-by: Mark Tolmacs <mark@lazycat.hu>

* chore: Try again removing non-needed modification

Signed-off-by: Mark Tolmacs <mark@lazycat.hu>

* fix: Inside-inside binding arrow endpoint drag trigger focus point editor

Signed-off-by: Mark Tolmacs <mark@lazycat.hu>

* fix: Area based edge case

Signed-off-by: Mark Tolmacs <mark@lazycat.hu>

* fix: Overlapping new arrow jump

Signed-off-by: Mark Tolmacs <mark@lazycat.hu>

---------

Signed-off-by: Mark Tolmacs <mark@lazycat.hu>
Co-authored-by: David Luzar <5153846+dwelle@users.noreply.github.com>

packages/element/src/utils.ts

@@ -43,6 +43,11 @@ import { LinearElementEditor } from "./linearElementEditor";
 import { isRectangularElement } from "./typeChecks";
 import { maxBindingDistance_simple } from "./binding";
 
+import {
+  getGlobalFixedPointForBindableElement,
+  normalizeFixedPoint,
+} from "./binding";
+
 import type {
   ElementsMap,
   ExcalidrawArrowElement,
@@ -677,11 +682,35 @@ export const projectFixedPointOntoDiagonal = (
     elementsMap,
   );
 
-  const a = LinearElementEditor.getPointAtIndexGlobalCoordinates(
+  // To avoid working with stale arrow state, we use the opposite focus point
+  // of the current endpoint, which will always be unchanged during moving of
+  // the endpoint. This is only needed when the arrow has only two points.
+  let a = LinearElementEditor.getPointAtIndexGlobalCoordinates(
     arrow,
     startOrEnd === "start" ? 1 : arrow.points.length - 2,
     elementsMap,
   );
+  if (arrow.points.length === 2) {
+    const otherBinding =
+      startOrEnd === "start" ? arrow.endBinding : arrow.startBinding;
+    const otherBindable =
+      otherBinding &&
+      (elementsMap.get(otherBinding.elementId) as
+        | ExcalidrawBindableElement
+        | undefined);
+    const otherFocusPoint =
+      otherBinding &&
+      otherBindable &&
+      getGlobalFixedPointForBindableElement(
+        normalizeFixedPoint(otherBinding.fixedPoint),
+        otherBindable,
+        elementsMap,
+      );
+    if (otherFocusPoint) {
+      a = otherFocusPoint;
+    }
+  }
+
   const b = pointFromVector<GlobalPoint>(
     vectorScale(
       vectorFromPoint(point, a),