Handle pre picking.

Author: D8H

examples/rtree/game.json

@@ -491,6 +491,14 @@
         {
           "name": "Obstacle",
           "type": "CollisionDetector::Solid"
+        },
+        {
+          "name": "Physics2",
+          "type": "Physics2::Physics2Behavior",
+          "gravityX": 0,
+          "gravityY": 9.8,
+          "scaleX": 100,
+          "scaleY": 100
         }
       ]
     },
@@ -1182,11 +1190,18 @@
                 "    const top = object.getAABBTop();\r",
                 "    const right = object.getAABBRight();\r",
                 "    const bottom = object.getAABBBottom();\r",
-                "    for (const objectName in solidObjectLists.items) {\r",
-                "        // Solid picking is ignored all solid are considered.\r",
-                "        nearObjects.length = 0;\r",
-                "        manager.getAllInstancesInRectangle(objectName, left, top, right, bottom, nearObjects);\r",
-                "        object.separateFromObjects(nearObjects);\r",
+                "    for (const solidObjectName in solidObjectLists.items) {\r",
+                "        const pickedObjects = solidObjectLists.items[solidObjectName];\r",
+                "        if (pickedObjects.length === runtimeScene.getInstancesCountOnScene(solidObjectName)) {\r",
+                "            nearObjects.length = 0;\r",
+                "            manager.getAllInstancesInRectangle(solidObjectName, left, top, right, bottom, nearObjects);\r",
+                "            object.separateFromObjects(nearObjects);\r",
+                "        }\r",
+                "        else {\r",
+                "            // Avoid to do intersection between pickedObjects and nearObjects\r",
+                "            // as it is O(n²) and the naive collision is O(n).\r",
+                "            object.separateFromObjects(pickedObjects);\r",
+                "        }\r",
                 "    }\r",
                 "}"
               ],