I have written a c++ library that needs opencv which is an image processing library. I want to now use this c++ library on ios. To do that I am going to copy my code to a mac and build to produce a cocoa touch static library.
Since, this has a dependency on opencv, I downloaded its ios framework. But now I am confused whether a framework can be used from c++ code or just from objective c/c++ ? Do I have to recompile this library so that i get c++ libraries or I can use the framework in my c++ code?
Yes, it can be used with c++. You will have to make sure you Type is set to "Objective C++ Source" for where you are making the framework calls.
I mix my C++ code with frameworks all the time.
Note this goes both ways. If you have Obj-C interacting with C++, you'll need to either have the file be a .mm or be of the "Objective C++ Source" Type.
The Type selection is in the File Inspector for files.
Related
According to docs
Kotlin/Native is a technology for compiling Kotlin code to native
binaries, which can run without a virtual machine. It is an LLVM based
backend for the Kotlin compiler and native implementation of the
Kotlin standard library.
So K/N is using LLVM to compile Kotlin code to native code for iOS. Swift compiler also uses LLVM to optimize and generate machine code.
So is there any difference between compiled K/N vs compiled Swift code on iOS platform?
If so what are those differences? Performance and etc.
The main difference is that Kotlin code compiled for iOS brings along the Kotlin/Native runtime which establishes the Kotlin/Native memory model that aims for safe concurrency and immutability of global objects, and also provides its own garbage collector for Kotlin objects.
Otherwise, code compiled with Kotlin/Native indeed has two-way interoperability with Swift, as normally the Kotlin binary that you use on iOS is an Objective-C framework that you can import in one project with Swift.
I want to use the openCV2 framework in my iOS app, however, I am more comfortable with swift. I can read and understand obj-c well enough to understand the framework and write the methods I need from it in a bridging header, but I'm not comfortable writing the whole app in obj-C. Unfortunately, there are some data types, (cv::Mat, cv::MserManager, etc) that I will need to use in my datamodel, or possibly elsewhere. Is there a way to include datatypes in my bridging header so that I can work with them in swift?
You cannot use C++ types in code called from Swift. However, you can use them in Objective-C++ files, the ones that have the .mm extension. You can mix Objective-C and C++ code in Objective-C++, and can expose Objective-C methods that don't reference C++ in their declarations to Swift via the bridging wrapper. These functions can still use C++ in their implementations, which are not visible in Swift via the bridging header.
You also need to be careful about the language linkage (remember extern "C"?).
Here are some answers that provide examples:
1) Video processing with OpenCV in IOS Swift project
2) Include C++ header file in Swift
3) How to access Swift-objects from a c++ class?
Unfortunately, you cannot bridge C++ and Objective-C++ directly into Swift. On the bright side, you can still work with the openCV2 framework in your app, but you'll need to write C or Objective-C wrappers for your types as described in a related question here: Can I mix Swift with C++? Like the Objective - C .mm files
I wrote a game for Android using Android NDK. Core of game logic written in pure C++. So, I want to port it to iOS. I know how to port Java (JNI) wrapping to Objective-C.
My question is how to organize this project on FS? I want to keep a single code base, and I use git (link).
First, note that there should be no need at all do wrap your C++ code: the objective-C extension of the C language is also compatible with C++. So, you can compile your code as "Objective-C++" and directly use C++ classes with Objective-C code.
Second, you can put your code anywhere you wish on the disk. Both eclipse for Android and xcode for iOS will let you include source code into your project from any relative directory.
If you ever need platform-specific native code you can use #ifdef __ANDROID__ for android-specific code inside your C++.
Where can I get sample tutorial where I can get how to use visual C++ files in XCODE using objective c? I am working on app which is having multiple visual C++ files. Basically this is an gaming application which is developed for windows. And now want to develop it on iPad. So can I reuse those files?
Thank you in Advance.
You can just add the c++ files directly to Xcode and it will compile them (assuming you have all the proper headers etc). You can create 'bridges' to that code by using ObjectiveC++ - meaning you can set the suffix of an ObjectiveC file to '.mm' and the methods in the file will be visible to any other ObjectiveC object, but you can instantiate C++ objects too. In fact if you have C++ ivars (object variables), they get the proper destruct messages when the ObjectiveC class is released. Google 'ObjectiveC++' for more info.
For one of my current iOS project, some business logic has been provided to me through a DLL and Native C++ binding code that i have to recompile in a dynamic library (dylib) and then use the DLL through this dynamic library.
Finally the DLL is used like this example:
int main(int argc, char** argv){
RTEnvironnement::CreateRTEnvironnement("../dll/RT.dll");
RT::RT_Facade * mFacade = new RT::RT_Facade();
RT::RT_Data_Projet * mProjet = new RT::RT_Data_Projet();
mProjet->Load_From_XMLFile(argv[1]);
...
Objects RTEnvironnement, RT_Facade, RT_Data_Projet are provided by the binding C++ dynamic lib. I cannot get the code of the base DLL and i have to use the DLL as it is on IOS.
I'm currently studying if mono touch can able my IOS app (basic iOS Objective C based on Xcode ), to launch the DLL that as been build with the standard mono framework. Before purchasing a license, I have to be sure that MonoTouch is able to do this.
Is someone do something similar ? Is there a simplest way to this ?
If i choose to use MonoTouch, can i keep my project in Xcode and just build the dylib in MonoDevelop and then import the lib the Xcode project ?
Thanks for your help.
the DLL that as been build with the standard mono framework.
MonoTouch (like Mono for Android) provide a base class library (BCL) profile that is similar (a superset) to Silverlight. However it's a subset of the whole Mono framework.
As such it's very common that assemblies compiled against the full framework won't work on MonoTouch unless they are re-compiled (against the MonoTouch BCL).
If i choose to use MonoTouch, can i keep my project in Xcode and just build the dylib in MonoDevelop and then import the lib the Xcode project ?
It's more complicated than that (e.g. MonoDevelop won't give you a .dylib). You might be able to google some instructions to do this, however be aware that this scenario is unsupported.
An supported alternative is to make MonoTouch drive the application, load any assemblies you need, expose those and then transfer control to your Objective-C code.