Optimize cases where loop variable is unecessarily copied in a range-for loop. (cocos2d#19637)

Pass by const reference when appropriate.

Author: JohnCoconut

cocos/2d/CCSpriteFrameCache.cpp

@@ -757,7 +757,7 @@ bool SpriteFrameCache::PlistFramesCache::erasePlistIndex(const std::string &plis
     if (it == _indexPlist2Frames.end()) return false;
 
     auto &frames = it->second;
-    for (auto f : frames)
+    for (const auto& f : frames)
     {
         // !!do not!! call `_spriteFrames.erase(f);` to erase SpriteFrame
         // only erase index here

cocos/2d/CCTMXXMLParser.cpp

@@ -752,7 +752,7 @@ void TMXMapInfo::endElement(void* /*ctx*/, const char *name)
             }
 
             uint32_t* bufferPtr = reinterpret_cast<uint32_t*>(buffer);
-            for(auto gidToken : gidTokens) {
+            for(const auto& gidToken : gidTokens) {
                 auto tileGid = (uint32_t)strtoul(gidToken.c_str(), nullptr, 10);
                 *bufferPtr = tileGid;
                 bufferPtr++;

cocos/3d/CCAnimate3D.cpp

@@ -392,7 +392,7 @@ void Animate3D::update(float t)
                     float prekeyTime = lastTime * getDuration() * _frameRate;
                     float keyTime = t * getDuration() * _frameRate;
                     std::vector<Animate3DDisplayedEventInfo*> eventInfos;
-                    for (auto keyFrame : _keyFrameUserInfos)
+                    for (const auto& keyFrame : _keyFrameUserInfos)
                     {
                         if ((!_playReverse && keyFrame.first >= prekeyTime && keyFrame.first < keyTime)
                             || (_playReverse && keyFrame.first >= keyTime && keyFrame.first < prekeyTime))

cocos/3d/CCAnimation3D.cpp

@@ -87,8 +87,9 @@ Animation3D::Animation3D()
 
 Animation3D::~Animation3D()
 {
-    for (auto itor : _boneCurves) {
-        CC_SAFE_DELETE(itor.second);
+    for (const auto& itor : _boneCurves) {
+        Curve* curve = itor.second;
+        CC_SAFE_DELETE(curve);
     }
 }
 

cocos/3d/CCBundle3D.cpp

@@ -2210,7 +2210,7 @@ std::vector<Vec3> Bundle3D::getTrianglesList(const std::string& path)
     Bundle3D::destroyBundle(bundle);
     for (auto iter : meshs.meshDatas){
         int preVertexSize = iter->getPerVertexSize() / sizeof(float);
-        for (auto indexArray : iter->subMeshIndices){
+        for (const auto& indexArray : iter->subMeshIndices){
             for (auto i : indexArray){
                 trianglesList.push_back(Vec3(iter->vertex[i * preVertexSize], iter->vertex[i * preVertexSize + 1], iter->vertex[i * preVertexSize + 2]));
             }

cocos/3d/CCSkeleton3D.cpp

@@ -202,7 +202,7 @@ void Bone3D::updateLocalMat()
         Quaternion quat(Quaternion::ZERO);
 
         float total = 0.f;
-        for (auto it: _blendStates) {
+        for (const auto& it: _blendStates) {
             total += it.weight;
         }
         if (total)

cocos/3d/CCTerrain.cpp

@@ -1335,7 +1335,7 @@ bool Terrain::Chunk::getIntersectPointWithRay(const Ray& ray, Vec3& intersectPoi
 
     float minDist = FLT_MAX;
     bool isFind = false;
-    for (auto triangle : _trianglesList)
+    for (const auto& triangle : _trianglesList)
     {
         Vec3 p;
         if (triangle.getIntersectPoint(ray, p))

cocos/editor-support/cocostudio/ActionTimeline/CCActionTimeline.cpp

@@ -176,7 +176,7 @@ ActionTimeline* ActionTimeline::clone() const
     newAction->setDuration(_duration);
     newAction->setTimeSpeed(_timeSpeed);
 
-    for (auto timelines : _timelineMap)
+    for (const auto& timelines : _timelineMap)
     {
         for(auto timeline : timelines.second)
         {      
@@ -185,7 +185,7 @@ ActionTimeline* ActionTimeline::clone() const
         }
     }
 
-    for( auto info : _animationInfos)
+    for(const auto& info : _animationInfos)
     {
         newAction->addAnimationInfo(info.second);
     }
@@ -416,7 +416,7 @@ void ActionTimeline::emitFrameEndCallFuncs(int frameIndex)
     if (clipEndCallsIter != _frameEndCallFuncs.end())
     {
         auto clipEndCalls = (*clipEndCallsIter).second;
-        for (auto call : clipEndCalls)
+        for (const auto& call : clipEndCalls)
             (call).second();
     }
 }

cocos/editor-support/cocostudio/CCArmatureDataManager.cpp

@@ -95,22 +95,22 @@ void ArmatureDataManager::removeArmatureFileInfo(const std::string& configFilePa
 {
     if (RelativeData *data = getRelativeData(configFilePath))
     {
-        for (std::string str : data->armatures)
+        for (const std::string& str : data->armatures)
         {
             removeArmatureData(str);
         }
 
-        for (std::string str : data->animations)
+        for (const std::string& str : data->animations)
         {
             removeAnimationData(str);
         }
 
-        for (std::string str : data->textures)
+        for (const std::string& str : data->textures)
         {
             removeTextureData(str);
         }
 
-        for (std::string str : data->plistFiles)
+        for (const std::string& str : data->plistFiles)
         {
             SpriteFrameCacheHelper::getInstance()->removeSpriteFrameFromFile(str);
         }

cocos/physics/CCPhysicsJoint.cpp

@@ -180,7 +180,7 @@ bool PhysicsJoint::initJoint()
 
 void PhysicsJoint::flushDelayTasks()
 {
-    for (auto tsk : _delayTasks)
+    for (const auto& tsk : _delayTasks)
     {
         tsk();
     }