From 61d12923ea794373ee6b951ea16125f9ebc2aff2 Mon Sep 17 00:00:00 2001
From: sabrina-shanman <sabrina@highfidelity.io>
Date: Mon, 13 Aug 2018 16:49:51 -0700
Subject: [PATCH] Do not copy list of collision pick contact points when
 filtering them

---
 interface/src/raypick/CollisionPick.cpp | 20 ++++++++++----------
 interface/src/raypick/CollisionPick.h   |  2 +-
 libraries/physics/src/PhysicsEngine.cpp |  2 +-
 libraries/physics/src/PhysicsEngine.h   |  2 +-
 4 files changed, 13 insertions(+), 13 deletions(-)

diff --git a/interface/src/raypick/CollisionPick.cpp b/interface/src/raypick/CollisionPick.cpp
index 87c8c91e6d..a70882eed0 100644
--- a/interface/src/raypick/CollisionPick.cpp
+++ b/interface/src/raypick/CollisionPick.cpp
@@ -308,20 +308,18 @@ CollisionRegion CollisionPick::getMathematicalPick() const {
     return _mathPick;
 }
 
-const std::vector<ContactTestResult> CollisionPick::filterIntersections(const std::vector<ContactTestResult>& intersections) const {
-    std::vector<ContactTestResult> filteredIntersections;
-
+void CollisionPick::filterIntersections(std::vector<ContactTestResult>& intersections) const {
     const QVector<QUuid>& ignoreItems = getIgnoreItems();
     const QVector<QUuid>& includeItems = getIncludeItems();
     bool isWhitelist = includeItems.size();
-    for (const auto& intersection : intersections) {
+    for (int i = 0; i < intersections.size(); i++) {
+        auto& intersection = intersections[i];
         const QUuid& id = intersection.foundID;
-        if (!ignoreItems.contains(id) && (!isWhitelist || includeItems.contains(id))) {
-            filteredIntersections.push_back(intersection);
+        if (ignoreItems.contains(id) || (isWhitelist && !includeItems.contains(id))) {
+            intersections[i] = intersections[intersections.size()-1];
+            intersections.pop_back();
         }
     }
-
-    return filteredIntersections;
 }
 
 PickResultPointer CollisionPick::getEntityIntersection(const CollisionRegion& pick) {
@@ -330,7 +328,8 @@ PickResultPointer CollisionPick::getEntityIntersection(const CollisionRegion& pi
         return std::make_shared<CollisionPickResult>(pick.toVariantMap(), CollisionPickResult::LOAD_STATE_NOT_LOADED, std::vector<ContactTestResult>(), std::vector<ContactTestResult>());
     }
     
-    const auto& entityIntersections = filterIntersections(_physicsEngine->getCollidingInRegion(MOTIONSTATE_TYPE_ENTITY, *pick.shapeInfo, pick.transform));
+    auto& entityIntersections = _physicsEngine->getCollidingInRegion(MOTIONSTATE_TYPE_ENTITY, *pick.shapeInfo, pick.transform);
+    filterIntersections(entityIntersections);
     return std::make_shared<CollisionPickResult>(pick, CollisionPickResult::LOAD_STATE_LOADED, entityIntersections, std::vector<ContactTestResult>());
 }
 
@@ -344,7 +343,8 @@ PickResultPointer CollisionPick::getAvatarIntersection(const CollisionRegion& pi
         return std::make_shared<CollisionPickResult>(pick.toVariantMap(), CollisionPickResult::LOAD_STATE_NOT_LOADED, std::vector<ContactTestResult>(), std::vector<ContactTestResult>());
     }
 
-    const auto& avatarIntersections = filterIntersections(_physicsEngine->getCollidingInRegion(MOTIONSTATE_TYPE_AVATAR, *pick.shapeInfo, pick.transform));
+    auto& avatarIntersections = _physicsEngine->getCollidingInRegion(MOTIONSTATE_TYPE_AVATAR, *pick.shapeInfo, pick.transform);
+    filterIntersections(avatarIntersections);
     return std::make_shared<CollisionPickResult>(pick, CollisionPickResult::LOAD_STATE_LOADED, std::vector<ContactTestResult>(), avatarIntersections);
 }
 
diff --git a/interface/src/raypick/CollisionPick.h b/interface/src/raypick/CollisionPick.h
index b3a7186893..bfc3487a62 100644
--- a/interface/src/raypick/CollisionPick.h
+++ b/interface/src/raypick/CollisionPick.h
@@ -92,7 +92,7 @@ protected:
     // Returns true if pick.shapeInfo is valid. Otherwise, attempts to get the shapeInfo ready for use.
     bool isShapeInfoReady();
     void computeShapeInfo(CollisionRegion& pick, ShapeInfo& shapeInfo, QSharedPointer<GeometryResource> resource);
-    const std::vector<ContactTestResult> filterIntersections(const std::vector<ContactTestResult>& intersections) const;
+    void filterIntersections(std::vector<ContactTestResult>& intersections) const;
 
     CollisionRegion _mathPick;
     PhysicsEnginePointer _physicsEngine;
diff --git a/libraries/physics/src/PhysicsEngine.cpp b/libraries/physics/src/PhysicsEngine.cpp
index efe1bddc97..cfe255e561 100644
--- a/libraries/physics/src/PhysicsEngine.cpp
+++ b/libraries/physics/src/PhysicsEngine.cpp
@@ -944,7 +944,7 @@ protected:
     }
 };
 
-const std::vector<ContactTestResult> PhysicsEngine::getCollidingInRegion(MotionStateType desiredObjectType, const ShapeInfo& regionShapeInfo, const Transform& regionTransform) const {
+std::vector<ContactTestResult> PhysicsEngine::getCollidingInRegion(MotionStateType desiredObjectType, const ShapeInfo& regionShapeInfo, const Transform& regionTransform) const {
     // TODO: Give MyAvatar a motion state so we don't have to do this
     btCollisionObject* myAvatarCollisionObject = nullptr;
     if (desiredObjectType == MOTIONSTATE_TYPE_AVATAR && _myAvatarController) {
diff --git a/libraries/physics/src/PhysicsEngine.h b/libraries/physics/src/PhysicsEngine.h
index c5ab0cfdee..854d61844f 100644
--- a/libraries/physics/src/PhysicsEngine.h
+++ b/libraries/physics/src/PhysicsEngine.h
@@ -126,7 +126,7 @@ public:
     void setShowBulletConstraintLimits(bool value);
 
     // Function for getting colliding ObjectMotionStates in the world of specified type
-    const std::vector<ContactTestResult> getCollidingInRegion(MotionStateType desiredObjectType, const ShapeInfo& regionShapeInfo, const Transform& regionTransform) const;
+    std::vector<ContactTestResult> getCollidingInRegion(MotionStateType desiredObjectType, const ShapeInfo& regionShapeInfo, const Transform& regionTransform) const;
 
 private:
     QList<EntityDynamicPointer> removeDynamicsForBody(btRigidBody* body);