fix: correct calculate rect bounding

src/views/ProjectView.vue

@@ -3,20 +3,19 @@
     <v-stage class="h-full w-full" ref="stage" :config="stageSize" @mousedown="handleMouseDown"
       @mousemove="handleMouseMove" @mouseup="handleMouseUp" @click="handleStageClick">
       <v-layer ref="layer">
-        <template v-for="item in list" :key="item.id">
+        <template v-for="item in objMap.values()" :key="item.id">
           <v-group :config="{
             x: item.x,
             y: item.y,
             draggable: true,
             id: `group-${item.id}`,
-          }" @dragstart="handleDragStart" @dragend="handleDragEnd">
-            <v-rect :config="{
-              x: item.box.x,
-              y: item.box.y,
-              width: item.box.width,
-              height: item.box.height,
+          }" @dragstart="handleDragStart" @dragend="handleDragEnd" @mouseover="handleCanvasObjectMouseOver">
+            <v-rect :config="item.config" />
+            <v-rect v-show="!isUndefined(item.box)" :config="{
+              ...item.box,
+              visible: !isUndefined(item.box),
               stroke: 'red',
-              strokeWidth: 1,
+              strokeWidth: 3,
             }">
             </v-rect>
           </v-group>
@@ -56,50 +55,88 @@ const stageSize = {
   height: window.innerHeight,
 };
 
+type CanvasObjectBox = {
+  x: number;
+  y: number;
+  width: number;
+  height: number;
+};
+
 type CanvasObject = {
+  type: "Rect";
+  config: Konva.RectConfig;
   id: string;
   x: number;
   y: number;
-  // rotation: number;
-  // scale: number;
-  object: Konva.Node;
-  box: {
-    x: number;
-    y: number;
-    width: number;
-    height: number;
-  };
+  box?: CanvasObjectBox;
 };
 
-const list = ref<CanvasObject[]>([]);
+function calculateRectBounding(
+  width: number,
+  height: number,
+  rotation: number,
+  padding?: number,
+) {
+  // calculate bounding box for rotated rectangle
+  const radians = (rotation * Math.PI) / 180;
+  const cos = Math.cos(radians);
+  const sin = Math.sin(radians);
+
+  // calculate corners of the rectangle
+  const corners = [
+    { x: 0, y: 0 },
+    { x: width, y: 0 },
+    { x: width, y: height },
+    { x: 0, y: height },
+  ].map((point) => ({
+    x: point.x * cos - point.y * sin,
+    y: point.x * sin + point.y * cos,
+  }));
+
+  // find bounding box dimensions
+  const minX = Math.min(...corners.map((p) => p.x));
+  const maxX = Math.max(...corners.map((p) => p.x));
+  const minY = Math.min(...corners.map((p) => p.y));
+  const maxY = Math.max(...corners.map((p) => p.y));
+
+  if (padding)
+    return {
+      x: minX - padding,
+      y: minY - padding,
+      width: maxX - minX + padding * 2,
+      height: maxY - minY + padding * 2,
+    };
+  else
+    return {
+      x: minX,
+      y: minY,
+      width: maxX - minX,
+      height: maxY - minY,
+    };
+}
+
+const objMap = reactive<Map<string, CanvasObject>>(new Map());
 onMounted(() => {
   for (let n = 0; n < 100; n++) {
     const id = Math.round(Math.random() * 10000).toString();
     const x = Math.random() * stageSize.width;
     const y = Math.random() * stageSize.height;
+    const width = 30 + Math.random() * 30;
+    const height = 30 + Math.random() * 30;
     const rotation = Math.random() * 180;
-    const scale = Math.random();
 
-    const star = new Konva.Star({
-      rotation: rotation,
-      id: id,
-      numPoints: 5,
-      innerRadius: 30,
-      outerRadius: 50,
-      fill: "#89b717",
-      opacity: 0.8,
-      scaleX: scale,
-      scaleY: scale,
-    });
-
-    list.value.push({
+    objMap.set(id, {
+      type: "Rect",
+      config: {
+        width: width,
+        height: height,
+        rotation: rotation,
+        fill: "grey",
+        id: id,
+      },
       id: id,
       x: x,
       y: y,
-      // rotation: rotation,
-      // scale: scale,
-      object: star,
-      box: star.getClientRect(),
     });
   }
 });
@@ -130,46 +167,6 @@ onMounted(() => {
   selectedBox.rotateEnabled(false);
 });
 
-function degToRad(angle: number) {
-  return (angle / 180) * Math.PI;
-}
-
-function getCorner(
-  pivotX: number,
-  pivotY: number,
-  diffX: number,
-  diffY: number,
-  angle: number,
-) {
-  const distance = Math.sqrt(diffX * diffX + diffY * diffY);
-  angle += Math.atan2(diffY, diffX);
-  const x = pivotX + distance * Math.cos(angle);
-  const y = pivotY + distance * Math.sin(angle);
-  return { x, y };
-}
-
-function getClientRect(element: Konva.Node) {
-  const { x, y, width, height, rotation } = element;
-  const rad = degToRad(rotation() ?? 0);
-
-  const p1 = getCorner(x(), y(), 0, 0, rad);
-  const p2 = getCorner(x(), y(), width(), 0, rad);
-  const p3 = getCorner(x(), y(), width(), height(), rad);
-  const p4 = getCorner(x(), y(), 0, height(), rad);
-
-  const minX = Math.min(p1.x, p2.x, p3.x, p4.x);
-  const minY = Math.min(p1.y, p2.y, p3.y, p4.y);
-  const maxX = Math.max(p1.x, p2.x, p3.x, p4.x);
-  const maxY = Math.max(p1.y, p2.y, p3.y, p4.y);
-
-  return {
-    x: minX,
-    y: minY,
-    width: maxX - minX,
-    height: maxY - minY,
-  };
-}
-
 function handleCacheChange(e: Event) {
   const target = e.target as HTMLInputElement;
   const shouldCache = isNull(target) ? false : target.checked;
@@ -192,12 +189,12 @@ function handleDragStart(e: Event) {
   dragItemId.value = target.id();
 
   // move current element to the top:
-  const item = list.value.find((i) => i.id === dragItemId.value);
-  if (isUndefined(item)) return;
-
-  const index = list.value.indexOf(item);
-  list.value.splice(index, 1);
-  list.value.push(item);
+  // const item = list.value.find((i) => i.id === dragItemId.value);
+  // if (isUndefined(item)) return;
+  //
+  // const index = list.value.indexOf(item);
+  // list.value.splice(index, 1);
+  // list.value.push(item);
 }
 
 function handleDragEnd() {
@@ -335,6 +332,43 @@ function handleMouseUp() {
 
   selectedIds.value = selected.map((node: Konva.Node) => node.id());
 }
+
+function handleCanvasObjectMouseOver(evt: Event) {
+  if (isNull(evt.target)) return;
+  const target = evt.target;
+
+  let object = null;
+  if (target instanceof Konva.Group) {
+    if (!target.hasChildren()) return;
+    object = target.children[0];
+  } else if (target instanceof Konva.Rect) {
+    object = target;
+  } else {
+    console.trace(`Not Konva class: ${target}`);
+    return;
+  }
+
+  // Get client rect
+  const objectConfig = objMap.get(object.id());
+  if (isUndefined(objectConfig)) {
+    console.error(`Not found object id: ${object.id()}`);
+    return;
+  }
+  if (isUndefined(objectConfig.box)) {
+    if (
+      objectConfig.config.width &&
+      objectConfig.config.height &&
+      objectConfig.config.rotation
+    ) {
+      objectConfig.box = calculateRectBounding(
+        objectConfig.config.width,
+        objectConfig.config.height,
+        objectConfig.config.rotation,
+        5,
+      );
+    } else console.error("Could not calculate rect bounding");
+  }
+}
 </script>
 
 <style>