Looking at the cross-platform nature of potrace http://potrace.sourceforge.net/, is it possible to compile this for iOS? If so, how?
Yes, it is possible to compile potrace for iOS.
As a matter of fact, most open source libraries using standard (GNU) configure tools that compile on MacOS X will easily compile on iOS, because they are likely free of platform-specific code (e.g. linuxisms) and standard configure tools allow cross-compilation.
You can compile these libraries in the shell by pointing configure to the proper toolchain and SDKs. Paths changed with Mavericks and Xcode 5, but fortunately automated scripts exist for more popular libraries such as expat.
The proposed solution is based on the x2on/expat-ios project on GitHub. Their script fixes expat's config.sub which doesn't know about arm64 target. Do does potrace 1.11's config.sub. However, a simpler approach consists in downloading a more recent version of config.sub. Unlike expat, potrace doesn't seem to need any patch to compile for iOS.
Full script build-potrace.sh is available here:
https://gist.github.com/pguyot/dce18af64a71b93c0204
Please note that potrace is licensed under the GPLv2. You might want to check Is it legal to publish iOS apps under the GNU GPLv3 open-source license? question.
Related
As part of a research project at school, I'm exploring mobile specific energy optimizations and am building infrastructure to test these optimizations on a popular mobile platform. Given my background in LLVM, I have decided to setup the testing infrastructure around the iOS platform. I thought that since Xcode already uses LLVM under the hood, it should be easy to integrate a copy of LLVM compiled from source into the Xcode toolchain, but I haven't been able to find an option to accomplish it in Xcode yet. (I'm new to OSX and haven't worked with Xcode before)
Am I overlooking anything, or is such an integration not supported out of the box in Xcode?
It's for obfuscater-llvm, but it should work for a "normal" llvm:
https://github.com/obfuscator-llvm/obfuscator/wiki/Installation#integration-into-xcode
I've installed xcode 5 and noticed that gcc compiler is deprecated. Assuming that I don't want to switch to Apple LLVM 5.0, here come my questions:
Is it possible to use iOS7 SDK and still compile in llvm-gcc-4.2?
If yes, how to do this?
If you don't know if that's possible, please don't post answers like "use clang, man", because they are not actually answering the questions I've posted.
Apple has removed the support for llvm-gcc-4.2 in XCode 5. Even if you install and change your base sdk to 6.1 sdk, you won't be able to build using llvm-gcc-4.2. So your only option is to continue using XCode 4.x if you want to use llvm-gcc-4.2.
LLVM-GCC is not included in Xcode 5.
I got above line from
https://developer.apple.com/library/ios/documentation/DeveloperTools/Conceptual/WhatsNewXcode/Articles/xcode_5_0.html
So the question is what to use instead of llvm-gcc ?
Is it possible to use iOS7 SDK and still compile in llvm-gcc-4.2?
If you want to compile your whole app using llvm-gcc-4.2: Probably not. I haven't checked this myself, but the iOS 7 headers would only need to add a single dependency on a clang feature missing in llvm-gcc-4.2 and you're swimming in compile errors. You may be able to hack your way through them, but it would likely be easier (not to mention more future-proof) to suck it up and upgrade to clang.
If you only need to compile some of your app using llvm-gcc-4.2: Sure, as long as you don't need to import any iOS 7 headers in the parts that you build with llvm-gcc-4.2.
You could try moving the problematic bits off to a static library, compiling that with gcc, then linking in to the final app, built with clang. You won't be able to target 64-bit, as llvm-gcc-4.2 doesn't can't generate armv8 code, but it should work otherwise.
One caveat: If your static lib uses C++, there may be some problems due to ABI and std library differences. But those are solvable problems, at least.
You could use homebrew to install the gcc version you need. Most probably all your Makefiles will need to be corrected (sigh)
I did:
brew search gcc
And the results:
homebrew/versions/gcc43
homebrew/versions/gcc45
homebrew/versions/gcc47
homebrew/versions/gcc49
homebrew/versions/gcc44
homebrew/versions/gcc45
homebrew/versions/gcc48
homebrew/versions/llvm-gcc28
homebrew/dupes/apple-gcc42
I'm using iOS 6.1 and XCode 4.6
I have a problem, OpenCV needs to be compiled with libc++ (LLVM C++ 11), while Tesseract 3.02.03 needs to be compiled with "default compiler".
How can I overcome this problem. at this point I can compile and link only If I comment out OpenCV code or comment out OCR code. cannot make them both work together.
Any ideas??
I am by no means an expert with C++ but I had the same problem and by some trial and error and lots of internet searching I think I managed to solve it.
As I understand it, the problem is that opencv and tesseract are built with different standard libraries. The latest opencv is built with libc++ while tesseract is built with stdlibc++
The solution is to rebuild one of them so they both use the same standard library. I decided to recompile tesseract and followed the instructions found here which references a build script that is used to build the library.
I modified this script (again, by trial an error, not really sure this is the best way) to used the clang++ compiler (CXX="/usr/bin/clang++") and use libc++ (CXXFLAGS="$CFLAGS -stdlib=libc++") and it compiles (albiet with some warnings). You may also need to copy some headers as the script doesn't seem to copy them all.
Then just use this library instead of the downloaded one in your iOS project (remember to change back to libc++ in build settings) and everything will compile and link just fine.
So far it seems to work properly in runtime.
I have a C lib and dll file from windows application. No source code with me.
Is it possible to use that in an IOS application.
I have seen mixed responses and am confused.
If we have source code , i think we need to create dylib and then we can use the same after including relevant header file.
Please share any expert ideas to guide me in right direction.
Appreciate your help .
mia
Dynamic Libraries are not permitted on iOS to begin with, but above that, the DLL file format is not recognized by Darwin or the underlying XNU Kernel at all, as the binary format is different.
Windows APIs are not usable on the Darwin OS either (Both Mac OS X and iOS are wrappers around the basic Darwin OS). You will need to rewrite the code from the DLL to use the POSIX and/or Objective-C APIs and compile it as a static library to use it.
You need to get a iOS compatible library, no other way around it. There are several reasons:
iOS doesn't support DLLs as they are windows format, but moreover, you can't use any dynamic library on iOS, as Apple restricts it.
DLLs are usually for intel CPUs, while iOS devices have ARM CPUs.
Most dlls are calling windows APIs - are you sure this one's not?
No. If you all you have is a compiled binary DLL, there is no way to use it on iOS. Unless you happen to have an ARM DLL for the upcoming Windows 8, your DLL contains either x86 or x86-64 machine code (or maybe IA64 if you have a lot of money), which absolutely will not run on iOS devices, which are all ARM architectures. Plus many more reasons.
If you have the source code, you can recompile it for iOS, either directly into your app, as a static library that can be linked in with your app, or as a dynamic library as part of a framework. But in all cases, you need to recompile it from source code using the iOS compiler.
You are going to have to recompile it as a static library (.a file). Apple doesn't allow dynamic libraries except for their own frameworks (so you can't compile it as a dylib).
Has anyone used Bluetooth on Mac OS X with Lazarus or FreePascal? There is a bluetooth unit, but it currently only supports Linux.
Information about existing unit:
http://wiki.freepascal.org/Bluetooth
I plan to enhance this to support Mac OS, but it would be nice to know if anyone has written any code to use BlueTooth on Mac OS already to avoid duplicated work.
On the other hand, if you have used XCode to access Bluetooth, what libraries did you use? I am sure I can discover this with the XCode profiler by opening some Bluetooth applications.
Note: Mac OS X doesn't appear to use the BlueZ library that Linux has, so I don't think the solution is as easy as changing the library path. Instead, it has IOBluetooth "Framework", located at /System/Library/Frameworks/IOBluetooth.framework.
Having a look, it looks like:
kaikei.ocn.ntt.com:IOBluetooth.framework $ file *
CodeResources: XML document text
Headers: directory
IOBluetooth: Mach-O universal binary with 3 architectures
IOBluetooth (for architecture x86_64): Mach-O 64-bit dynamically linked shared library x86_64
IOBluetooth (for architecture i386): Mach-O dynamically linked shared library i386
IOBluetooth (for architecture ppc7400): Mach-O dynamically linked shared library ppc
Resources: directory
Versions: directory
On the other hand, I think if anyone had done this already, I would probably be able to find it on Google.... On the off chance I am wrong, please reply and let me know.
Clarification: I have created bindings for normal shared libraries before (f.e. sqlite3), but not for a "framework". If nobody has created bindings or otherwise used the MacOS Bluetooth framework from FreePascal, advice on how to use framework functions from FreePascal in general woule be appreciated. (And normally the functions I am porting are C based, not Obj-C, so I am not sure how to declare Obj-C methods in FPK, although I am sure I will be able to find some samples if I keep searching).
The main svn repository for translated Mac OS X framework C headers is http://svn.freepascal.org/svn/macosxintf/trunk
From time to time, FPC releases are synchronised with the latest versions hosted there. Note that the files in that repository (in the MPPInterfaces subdirectory) are in a generic format that can be automatically translated into either FPC, GPC or CodeWarrior Pascal versions.
To generate the FPC versions, use "make fpcpinterfaces", and find the results in the Build/FPCPinterfaces folder.
To translate new headers, execute something like this from inside a checked out copy of the macosxintf repository:
./Scripts/Convert.pl /System/Library/Frameworks/IOBluetooth.framework/Headers/IOBluetooth.h FORCE MPPInterfaces
Afterwards, you'll still have to edit the resulting file to add/remove units and clean up some other things not handled by the automatic translation process. Once finished, you may want to submit a bug report at bugs.freepascal.org with the finished units.
(note: because I'm unregistered, I can only add in one url per post, so the next url's are a bit mangled to get around that restriction)
You can also subscribe to the Mac Pascal list (lists.sonic.net/mailman/listinfo/mac-pascal) and ask there whether someone already translated those headers.
The Bluetooth framework indeed also contains some Objective-C headers. Objective-Pascal support is only available in the latest FPC svn versions, as described on the FPC wiki (google FPC_PasCocoa). You need this support in order to interface with Objective-C.
Translating Objective-C is probably easiest using the script elsewhere in FPC's svn (svn.freepascal.org/svn/fpc/trunk/packages/cocoaint/utils/)
You may want to ask for help on the above-mentioned Mac Pascal list, as all people maintaining the aforementioned translations and translation tools are subscribed there.