Now it shoudl run fine on iOS

cocos/renderer/CCRenderer.cpp

@@ -39,6 +39,7 @@
 #include "base/CCEventType.h"
 #include "2d/platform/CCImage.h"
 #include "2d/platform/CCFileUtils.h"
+#include "CCGLView.h"
 
 NS_CC_BEGIN
 
@@ -546,20 +547,28 @@ void Renderer::captureScreen(std::function<void(bool, const std::string&)> after
 
 void Renderer::onCaptureScreen(std::function<void(bool, const std::string&)> afterCaptured, const std::string& filename, bool flipped, const Rect& rect)
 {
-    float scaleFactor = Director::getInstance()->getContentScaleFactor();
-    int originx = (int)rect.origin.x;
-    int originy = (int)rect.origin.y;
-    int width = (int)rect.size.width * scaleFactor;
-    int height = (int)rect.size.height * scaleFactor;
+    // Generally the user specifiy the rect with design resolution, thus we have to convert it
+    // into a significant value which is metered by pixel.
+    Size frameSize = Director::getInstance()->getOpenGLView()->getFrameSize();
+    int originx = 0;
+    int originy = 0;
+    int width = (int)frameSize.width;
+    int height = (int)frameSize.height;
     bool succeed = false;
-    std::string targetFile = "";
+    std::string outputFile = "";
 
-    if (rect.equals(Rect::ZERO))
+    if (!rect.equals(Rect::ZERO))
     {
-	    originx = 0;
-	    originy = 0;
-	    width  = (int)Director::getInstance()->getWinSize().width * scaleFactor;
-	    height = (int)Director::getInstance()->getWinSize().height * scaleFactor;
+        originx = (int)rect.origin.x;
+        originy = (int)rect.origin.y;
+        width = (int)rect.size.width * Director::getInstance()->getOpenGLView()->getScaleX();
+        height = (int)rect.size.height * Director::getInstance()->getOpenGLView()->getScaleY();
+        
+        auto clip = [](int in, int min, int max) { return std::max(std::min(in, max), min); };
+        originx = clip(originx, 0, (int)frameSize.width);
+        originy = clip(originy, 0, (int)frameSize.height);
+        width = clip(width, 0, frameSize.width - originx);
+        height = clip(height, 0, frameSize.height - originy);
     }
 
     do
@@ -596,14 +605,14 @@ void Renderer::onCaptureScreen(std::function<void(bool, const std::string&)> aft
         {
             image->initWithRawData(buffer, width * height * 4, width, height, 8);
             CC_SAFE_DELETE_ARRAY(buffer);
-            targetFile = FileUtils::getInstance()->getWritablePath() + filename;
-            image->saveToFile(targetFile);
+            outputFile = FileUtils::getInstance()->getWritablePath() + filename;
+            image->saveToFile(outputFile);
             succeed = true;
         }
         CC_SAFE_DELETE(image);
     }while(0);
     	
-    afterCaptured(succeed, targetFile);
+    afterCaptured(succeed, outputFile);
 }
 
 NS_CC_END

tests/cpp-tests/Classes/NewRendererTest/NewRendererTest.cpp

@@ -561,6 +561,7 @@ std::string VBOFullTest::subtitle() const
     return "VBO full Test, everthing should render normally";
 }
 
+const int CaptureScreenTest::ChildTag;
 CaptureScreenTest::CaptureScreenTest()
 {
     Size s = Director::getInstance()->getWinSize();
@@ -589,7 +590,7 @@ CaptureScreenTest::CaptureScreenTest()
     addChild(menu);
     menu->setPosition(s.width / 2, s.height / 4);
 
-    _savedFilename = "";
+    _filename = "";
 }
 
 CaptureScreenTest::~CaptureScreenTest()
@@ -608,25 +609,25 @@ std::string CaptureScreenTest::subtitle() const
 
 void CaptureScreenTest::onCaptured(Ref*, const Rect& rect)
 {
-	TextureCache::getInstance()->removeTextureForKey(_savedFilename);
-	removeChildByTag(119);
-    _savedFilename = "CaptureScreenTest-Shot.png";
+    Director::getInstance()->getTextureCache()->removeTextureForKey(_filename);
+	removeChildByTag(ChildTag);
+    _filename = "CaptureScreenTest.png";
     Director::getInstance()->getRenderer()->captureScreen(
 	    CC_CALLBACK_2(CaptureScreenTest::afterCaptured, this),
-	    _savedFilename,
+	    _filename,
 	    rect);
 }
 
-void CaptureScreenTest::afterCaptured(bool succeed, const std::string& target)
+void CaptureScreenTest::afterCaptured(bool succeed, const std::string& outputFile)
 {
     if (succeed)
     {
-	    auto sp = Sprite::create(target);
-	    addChild(sp, 0, 119);
+	    auto sp = Sprite::create(outputFile);
+	    addChild(sp, 0, ChildTag);
 	    Size s = Director::getInstance()->getWinSize();
 	    sp->setPosition(s.width / 2, s.height / 2);
 	    sp->setScale(0.25);
-        _savedFilename = target;
+        _filename = outputFile;
     }
     else
     {

tests/cpp-tests/Classes/NewRendererTest/NewRendererTest.h

@@ -148,6 +148,7 @@ protected:
 
 class CaptureScreenTest : public MultiSceneTest
 {
+    static const int ChildTag = 119;
 public:
     CREATE_FUNC(CaptureScreenTest);
     virtual std::string title() const override;
@@ -158,9 +159,9 @@ protected:
     ~CaptureScreenTest();
 
     void onCaptured(Ref*, const Rect& rect);
-    void afterCaptured(bool succeed, const std::string& target);
+    void afterCaptured(bool succeed, const std::string& outputFile);
 
-    std::string _savedFilename;
+    std::string _filename;
 };
 
 #endif //__NewRendererTest_H_