From d6dfa596de22518b493a29fd6bbf90a948c546a2 Mon Sep 17 00:00:00 2001
From: Josh Hawkins <32435876+hawkeye217@users.noreply.github.com>
Date: Fri, 19 Apr 2024 08:59:28 -0500
Subject: [PATCH] undo points based on order added to polygon (#11035)

---
 web/src/components/settings/PolygonCanvas.tsx | 82 +++++++++----------
 .../settings/PolygonEditControls.tsx          | 31 +++++--
 web/src/types/canvas.ts                       |  2 +-
 3 files changed, 64 insertions(+), 51 deletions(-)

diff --git a/web/src/components/settings/PolygonCanvas.tsx b/web/src/components/settings/PolygonCanvas.tsx
index 22c23a226..d21ef01bf 100644
--- a/web/src/components/settings/PolygonCanvas.tsx
+++ b/web/src/components/settings/PolygonCanvas.tsx
@@ -61,9 +61,20 @@ export function PolygonCanvas({
 
   const addPointToPolygon = (polygon: Polygon, newPoint: number[]) => {
     const points = polygon.points;
+    const pointsOrder = polygon.pointsOrder;
+
     const [newPointX, newPointY] = newPoint;
     const updatedPoints = [...points];
 
+    let updatedPointsOrder: number[];
+    if (!pointsOrder) {
+      updatedPointsOrder = [];
+    } else {
+      updatedPointsOrder = [...pointsOrder];
+    }
+
+    let insertIndex = points.length;
+
     for (let i = 0; i < points.length; i++) {
       const [x1, y1] = points[i];
       const [x2, y2] = i === points.length - 1 ? points[0] : points[i + 1];
@@ -76,48 +87,16 @@ export function PolygonCanvas({
           (y1 <= newPointY && newPointY <= y2) ||
           (y2 <= newPointY && newPointY <= y1)
         ) {
-          const insertIndex = i + 1;
-          updatedPoints.splice(insertIndex, 0, [newPointX, newPointY]);
+          insertIndex = i + 1;
           break;
         }
       }
     }
 
-    return updatedPoints;
-  };
+    updatedPoints.splice(insertIndex, 0, [newPointX, newPointY]);
+    updatedPointsOrder.splice(insertIndex, 0, updatedPoints.length);
 
-  const isPointNearLineSegment = (
-    polygon: Polygon,
-    mousePos: number[],
-    radius = 10,
-  ) => {
-    const points = polygon.points;
-    const [x, y] = mousePos;
-
-    for (let i = 0; i < points.length; i++) {
-      const [x1, y1] = points[i];
-      const [x2, y2] = i === points.length - 1 ? points[0] : points[i + 1];
-
-      const crossProduct = (x - x1) * (x2 - x1) + (y - y1) * (y2 - y1);
-      if (crossProduct > 0) {
-        const lengthSquared = (x2 - x1) * (x2 - x1) + (y2 - y1) * (y2 - y1);
-        const dot = (x - x1) * (x2 - x1) + (y - y1) * (y2 - y1);
-        if (dot < 0 || dot > lengthSquared) {
-          continue;
-        }
-        const lineSegmentDistance = Math.abs(
-          ((y2 - y1) * x - (x2 - x1) * y + x2 * y1 - y2 * x1) /
-            Math.sqrt(Math.pow(y2 - y1, 2) + Math.pow(x2 - x1, 2)),
-        );
-        if (lineSegmentDistance <= radius) {
-          const midPointX = (x1 + x2) / 2;
-          const midPointY = (y1 + y2) / 2;
-          return [midPointX, midPointY];
-        }
-      }
-    }
-
-    return null;
+    return { updatedPoints, updatedPointsOrder };
   };
 
   const isMouseOverFirstPoint = (polygon: Polygon, mousePos: number[]) => {
@@ -176,18 +155,15 @@ export function PolygonCanvas({
         !activePolygon.isFinished &&
         !isMouseOverAnyPoint(activePolygon, mousePos)
       ) {
-        let updatedPoints;
+        const { updatedPoints, updatedPointsOrder } = addPointToPolygon(
+          activePolygon,
+          mousePos,
+        );
 
-        if (isPointNearLineSegment(activePolygon, mousePos)) {
-          // we've clicked near a line segment, so add a new point in the right position
-          updatedPoints = addPointToPolygon(activePolygon, mousePos);
-        } else {
-          // Add a new point to the active polygon
-          updatedPoints = [...activePolygon.points, mousePos];
-        }
         updatedPolygons[activePolygonIndex] = {
           ...activePolygon,
           points: updatedPoints,
+          pointsOrder: updatedPointsOrder,
         };
         setPolygons(updatedPolygons);
       }
@@ -318,6 +294,24 @@ export function PolygonCanvas({
     e.target.getStage()!.container().style.cursor = "crosshair";
   };
 
+  useEffect(() => {
+    if (activePolygonIndex === undefined || !polygons) {
+      return;
+    }
+
+    const updatedPolygons = [...polygons];
+    const activePolygon = updatedPolygons[activePolygonIndex];
+
+    // add default points order for already completed polygons
+    if (!activePolygon.pointsOrder && activePolygon.isFinished) {
+      updatedPolygons[activePolygonIndex] = {
+        ...activePolygon,
+        pointsOrder: activePolygon.points.map((_, index) => index),
+      };
+      setPolygons(updatedPolygons);
+    }
+  }, [activePolygonIndex, polygons, setPolygons]);
+
   return (
     <Stage
       ref={stageRef}
diff --git a/web/src/components/settings/PolygonEditControls.tsx b/web/src/components/settings/PolygonEditControls.tsx
index ba979fc82..5aa4323b2 100644
--- a/web/src/components/settings/PolygonEditControls.tsx
+++ b/web/src/components/settings/PolygonEditControls.tsx
@@ -21,12 +21,31 @@ export default function PolygonEditControls({
 
     const updatedPolygons = [...polygons];
     const activePolygon = updatedPolygons[activePolygonIndex];
-    updatedPolygons[activePolygonIndex] = {
-      ...activePolygon,
-      points: [...activePolygon.points.slice(0, -1)],
-      isFinished: false,
-    };
-    setPolygons(updatedPolygons);
+
+    if (
+      activePolygon.points.length > 0 &&
+      activePolygon.pointsOrder &&
+      activePolygon.pointsOrder.length > 0
+    ) {
+      const lastPointOrderIndex = activePolygon.pointsOrder.indexOf(
+        Math.max(...activePolygon.pointsOrder),
+      );
+
+      updatedPolygons[activePolygonIndex] = {
+        ...activePolygon,
+        points: [
+          ...activePolygon.points.slice(0, lastPointOrderIndex),
+          ...activePolygon.points.slice(lastPointOrderIndex + 1),
+        ],
+        pointsOrder: [
+          ...activePolygon.pointsOrder.slice(0, lastPointOrderIndex),
+          ...activePolygon.pointsOrder.slice(lastPointOrderIndex + 1),
+        ],
+        isFinished: false,
+      };
+
+      setPolygons(updatedPolygons);
+    }
   };
 
   const reset = () => {
diff --git a/web/src/types/canvas.ts b/web/src/types/canvas.ts
index 5eb04e98f..4fcf8a46a 100644
--- a/web/src/types/canvas.ts
+++ b/web/src/types/canvas.ts
@@ -7,8 +7,8 @@ export type Polygon = {
   type: PolygonType;
   objects: string[];
   points: number[][];
+  pointsOrder?: number[];
   isFinished: boolean;
-  // isUnsaved: boolean;
   color: number[];
 };