Porting a C++ project into an iOS app? - c++

project compiles fine, how do I export it as an iOS app though
I have a large C++ project that I'd like to turn into an iOS app... any tips on how I might go about doing this? What I've done so far is to use CMake to generate an XCode project. I've been able to subsequently build (and archive -- but I can't find the archives in the organizer) my project in XCode, but to my understanding this is merely using XCode as an IDE...
Is there an easy way to remedy this situation? Or do I need to reconstruct the project all over again iOS style. If so, any guides you might recommend?

.mm files compile to objective-c++.
This is how you will get c++ code to talk to all the IOS libraries, which unfortunately are only generally easily available in objective-c and swift.
So create c++ interfaces in .h or .hpp files, and back them up with an objective-c++ impl that then talks to the objective-c runtime.
To get cmake to work nicely with iOS, you'll need a toolchain file.
There is a nice collection that you can use as a starting point here:
https://github.com/ruslo/polly

Related

Xcode autocompletion does not work for C++ libraries included via CMake

I have an Objective-C based project with some C++ code. I have included library I want to use via CMake. However, Xcode autocompletion is not working properly for library's methods, classes and etc.
Despite that, project compiles and there are no errors during build after inputting some of the library classes or functions in code. Xcode can also correctly specify the error, if I miss something like required parameters for method call (It will show up build error, telling which parameter I forgot to use).
The problem is lack of autocompletion dramatically slows down the development and I need to fix it.
Considering the fact that Xcode is essentially just another UNIX make with GUI on top of it, I would advice just switching to VSCode because the C++ plugin there is designed to work with this kind of stuff.
In your case you could probably use some automatic cmake -> pbx generator if such tools even exist. Or, of course, do this manually, and configure the compilation out of an Xcode project.

Is it possible to include framework in C++ project in Xcode?

I have a C++ project generated from Cmake to Xcode. My project is just some static and dynamic libraries. I want to include some 3rd party frameworks to it.
Is it possible? Is there any chance to include? Or I should completely redesign the project to Cocoa app?
I haven't access to the framework source code.
Work with Xcode 9.2.
No, you can't use Cocoa frameworks in pure C++ project.
But you can just create an obj-c project and include all of your existing sources inside - everything will work. Just remember to use .mm extension for the source files, calling C++ code.
You can use swift as well, but that will require to create a wrapper for C++ code.

Link c++ object during runtime?

I'm trying to write my first game in c++, and I want it to dynamically load everything from files. This includes the enemies, and I was wondering if there was a way to dynamically include their code at runtime, instead of linking the on compile, so that the levels are easily interchangeable. Lua might be an option but I have no clue where to start, and dll seems to be Windows-only (and I wouldn't know where to start there anyway). Can anyone help with this?
tl;dr I want to link in code to my c++ game at runtime.
For the Lua approach you first need to choose the version first. Right now there is the major version 5.1 and 5.2. My previous work was using 5.1 and for my new project I decided to update to 5.2, however I found that my favorite script wrapping tool (SWIG) does not work with 5.2. Just something to decide at the beginning, because you do not want to get a version working and then have to change it.
Lua comes with makefile build environment. My first experience of trying to build on Windows was a bit of a nightmare, did not appear to just run out-of-the-box, so I opted to create my own Visual Studio project at the time, and just include all the .C files in the project. There are two files which need to selectively included/excluded depending on how you intend to compile: lua.c and luac.c. If you are planning to embed Lua in your app, then exclude both of these files; they both contain a main() function and are designed to build console apps. Include all the rest of the C files in your project.
You should be able to compile easy from this point.
When you include the headers of Lua, keep in mind that the functions are C functions so if you are including them from C++ you need to wrap the file inclusion inside of: extern "C" {} - example: C++ Lua 5.1 Issue
Wrapping your interfaces in another topic and there are lots of resources available. My favorite is SWIG but there are lots of options, including hand coding the conversion of your C/C++ -> LUA -> C/C++ code. Would recommend just focusing on getting the first part working first, get the interpreter embedded so that you can run a "hello, world!" script from Lua inside your app.
So going by your requirement of crossplatform use and dynamic linking, what you're probably looking for is an environment like QT which has QLibrary: https://stackoverflow.com/a/9675063/453673
But https://softwareengineering.stackexchange.com/questions/88685/why-arent-more-desktop-apps-written-with-qt
MingW is the open-source equivalent for Visual C++, so it can help you writing code for Windows (though if I had a choice, I'd directly use Visual C++). The way dll's are loaded in Windows is somewhat similar to the way they're loaded in Linux, so you'll be able to write code with #ifdef's to do conditional compilation. I've written one such program a couple of years back.
To load a shared library(always with .so as suffix) under Linux, you could use dlopen(), dlsym() and dlclose()

Can eclipse do auto-complete using external libraries like cocos2d?

I'm using Eclipse in linux. I have created a project using Cocos2D. It's a Java project, but im opening cpp and headers files to write native code.
Each time, i compile the native code with ./build_native.sh
I will like to know if eclipse could be configure to autocomplete functions in native code.
Example:
CCDirector::sharedDirector()->
Must show the options like getWinSize().
Some ideas? Thanks in advance.
I can't answer to the specifics of your question but in general I had this problem in C/C++ with iostream and STL libs. Even though everything would compile fine it wasn't supporting auto-complete. I ended up digging down into the supplied libraries to the root that held each .h file collection and added those to the directories path. Then I rebuilt the index and then auto-complete started working. So if cocos2d stores .h files in more than one location add each folder.
Have you installed the CDT? That give Eclipse C/C++ capabilities similar to what it already has for Java.

Import existing C++ project into Xcode IDE

I am trying to open an existing C++ open-source library in Xcode to publish it with my own modification/additions. The library is Tesseract-OCR, which does not include a .xcodeproj file.
Since Xcode can function as an IDE, is it possible to open a bunch of files as a single project in Xcode? Is there an easy way to produce an Xcode project?
There are several ways you could do it, depending on the level of IDE integration you want. There's no direct way of importing a Makefile-based project into Xcode. You can create a project that builds via the Makefile, but you wouldn't get many of the benefits of using an IDE, since the editor features such as word completion rely on Xcode being able to parse the files in the project. You will be able to use the debugger though. To do this, create a new project and add a custom target with a script build phase that just calls down to Makefile.
If however the project you're building compiles very easily, ie without requiring a lot of macros to be set up, include paths, etc, then it may be simple to just create an empty project and merely add all source files to it. I've used this method extensively for building boost libraries. If this is a configure && make type project then you will probably have to run the configure step first, and ensure any top level config.h files are included in the project.
If the project has a complex makefile then it is likely to be an involved task to create a useful Xcode project
I realise you asked explicitly for Xcode, but in case you were actually trying to solve the problem of "I have existing C++ code which builds and runs fine from the command line, and I'd like to code and debug it in an IDE, what should I do?" my firm recommendation would be to avoid Xcode and go for Eclipse.
The reason is that as far as I can tell, Xcode has no way of ingesting the command line build environment and effectively requires you to recreate the make process inside Xcode from scratch. Fine for tiny projects, but anything with more than a few source files and it quickly becomes painful. Whereas in Eclipse everything is built around Makefiles. So in my case I got to the "step through code with working code completion" in Eclipse a lot quicker vs. never in Xcode. This of course could be because I'm an Xcode noob, but my 2c.
To create an Xcode project from an existing cmake project, you can run cmake -G Xcode. It produces some folders and files apart from the project file, so it might be better to create a folder for it first. For example:
mkdir -p build/xcode
cd build/xcode
cmake -G Xcode ../..
Xcode is a useable IDE for library creation.
Of course a good first step is to see if the one source code will build on its own with configure scripts that are included.
If not, it becomes a question of how many libraries you need to link in.
There are resources online (or at least there used to be) for using Xcode (or perhaps it's forerunner Product builder) for porting Unix projects to Mac.
Good tutorial at: http://www.macresearch.org/tutorial-introducing-xcode-30-organizer
Another good reference is Darwin Ports.
As for doing this on your own. You can build c++ based libraries in XCode. People do that every day. You can even use one of the Xcode templates to get you started.
However, library dev requires more experience with Xcode then say a simple Cocoa "Hello World" app.
The remaining questions will be assuring that the source code's dependencies are already built into the Mac's SDK. (Don't hold your breath for linking to MFC)
It's a general question... So it's a general answer.
In Xcode8,there is "Xcode->file->add files to...",then choose your files.If you want to add several files at a time,press "Cmd" when you are choosing.