Tool Native Library Generator (C/C++ to B4A)

Discussion in 'Additional libraries, classes and official updates' started by wonder, Jan 8, 2016.

  1. wonder

    wonder Expert Licensed User

    Native Library Generator 4.20 (2018-11-11)
    Written in B4J, this program allows you to write or import C/C++ code and have all the functions compiled into a native (.so) library, which in turn is included in a ready-to-use B4A Java lib. When using already existing code, if present, the main() function will be automatically ignored. If you're familiar with C/C++ but not with JNI or NDK, this is the right tool for you! No JAVA required.


    Open Source:
    This project is open source, under the GNU General Public License. Enjoy! :)

    Price (pay what you want):
    If you wish to buy me a beer (or even dinner!) just follow the link below.

    How does it work:

    Video Demos:

    [Version 4.21] [2018-11-12] [CRITICAL]
    QuickSource mode fixed
    For background music add "nlg.mp3" to the NLG folder ;)

    [Version 4.20] [2018-11-11] [NEW FEATURES]
    Now supporting multiple source files
    Select which files should be exposed to B4A
    Requires NDK r18b (please update)
    Bug fixes

    [Version 4.01] [2017-05-07] [NEW FEATURES]
    The 'cpu-features' library can now be used
    Custom Makefiles may now be used
    Custom Java wrappers may now be used
    Bug fixes

    [Version 4.00] [2017-05-07] [NEW FEATURES]
    Complete visual overhaul
    Specifying additional include paths is now possible
    Specifying additional prebuilt libraries is now possible
    Specifying the target ABI's is now possible
    Compatible ABI's are now auto-detected if possible
    multiple projects is now possible

    [Version 3.0] [2017-05-07] [NEW FEATURES]
    Returning arrays is now possible.
    B4A logging with printf() is now possible.

    [Version 2.9] [2016-08-12] [NEW FEATURES]
    Small UI redesign and bug fixes.
    Code clean-up.

    Little bit more user-friendly.
    Custom makefiles.

    [Version 2.8] [2016-07-12] [NEW FEATURES]
    Now supporting local #include files.
    Now supporting external project locations.
    New video demo.
    Minor bug fixes.

    [Version 2.7] [2016-03-14] [CRITICAL]
    Major bug fixes.

    [Version 2.6] [2016-01-31] [IMPORTANT]
    Important bug fixes.
    MazeSolver 1.5 Included as example source code.

    [Version 2.5] [2016-01-31] [NEW FEATURES]
    Now supporting comment transcription from C++ to B4A.
    New splash screen.
    Minor bug fixes.

    [Version 2.4] [2016-01-27] [CRITICAL]
    Critical bug fix regarding string (char*) support.
    Cool new intro/exit screens added.

    [Version 2.3] [2016-01-25] [NEW FEATURES]
    Now supporting Strings (char*), both passing and returning.

    [Version 2.2] [2016-01-20] [IMPORTANT]
    Now supporting simple C/C++ typedef struct.
    Now supporting C/C++ inline functions.

    Minor bug fixes.

    [Version 2.1] [
    2016-01-12] [CRITICAL]
    Included example (NinjaCore) source code updated. Several bug fixes.

    [Version 2.1] [2016-01-12] [IMPORTANT]
    Now supporting C++ headers, such as <vector> or <algorithm>.

    [Version 2.0] [2016-01-10] [CRITICAL]
    Major issue corrected. Please download Native Library Generator again.

    Included Example:

    In order to showcase this software's capabilities, I decided to include my MazeSolver project.

    A. Download link:

    B. Instructions (QuickSource Mode):
    In QuickSouce mode all you have to do is write some code and hit the Generate Library button.

    1. Before anything else, please make sure you have installed the following required software:
    B4A, Simple Library Compiler and Android NDK

    2. Download the .jar file into a system-writable folder (NOT Program Files).

    3. Run NLG and provide the necessary software paths, as seen below.

    4. Compile the example by clicking the big blue button.

    5. Test the library you just compiled with this B4A project:

    6. As you can see, it works!

    C. LibFastMath Example code (Copy/Paste to NLG):
    //LibFastMath 1.00 - Native Library Example

    and FastCos() by Allen Chou

    //FastSqrt() adapted from Quake 
    3's Fast Inverse Square Root algorithm

    #define PI         (3.1415926535f)
    #define HALF_PI    (0.5f * PI)
    #define TWO_PI     (2.0f * PI)
    #define TWO_PI_INV (1.0f / TWO_PI)

    float FastSin(float x);
    float FastCos(float x);
    float FastSqrt(float x);

    inline float Hill(float x)
    const float a0 = 1.0f;
    const float a2 = 2.0f / PI - 12.0f / (PI * PI);
    const float a3 = 16.0f / (PI * PI * PI) - 4.0f / (PI * PI);
    const float xx = x * x;
    const float xxx = xx * x;

    return a0 + a2 * xx + a3 * xxx;

    float FastSin(float x)
      // wrap x within [0, TWO_PI)
      const float a = x * TWO_PI_INV;
      x -= static_cast<int>(a) * TWO_PI;
      if (x < 0.0f)
        x += TWO_PI;

      // 4 pieces of hills
      if (x < HALF_PI)
        return Hill(HALF_PI - x);
      else if (x < PI)
        return Hill(x - HALF_PI);
      else if (x < 3.0f * HALF_PI)
        return -Hill(3.0f * HALF_PI - x);
        return -Hill(x - 3.0f * HALF_PI);

    float FastCos(float x)
      return FastSin(x + HALF_PI);

    float FastSqrt(float x)
        //This is the method used in Quake3
        const float xhalf = 0.5f*x;

        //Get bits for floating value
            float x;
            int i;
        } u;
        u.x = x;

        //Give initial guess y0
        u.i = 0x5f3759df - (u.i >> 1);

        //Newton step, repeating increases accuracy
        return (x*u.x*(1.5f - xhalf*u.x*u.x));

    D. How does it work:
    Initially, I created this program in order to speed-up the process of writing JNI C/C++ code. Following B4A's RAD philosophy, it allows me to write native code in Visual Studio and compile it into a fully-working B4A lib within a single click.
    E. Internal Functions:
    If you wish any of your native function not to be exposed in the B4A library, you may do so by either changing their name from foo() into privateFoo() or simply adding a "::ignore" the function's comments.
    //This function will not be visible in B4A because its name starts with "private".
    int privateSum(int a, int b)
    return a + b;

    //This function will not be visible in B4A because this comment contains the keyword "::ignore".
    int multiplication(int a, int b)
        return a * b;

    //This function will be exposed in B4A.
    int result(int a, int b)
        return privateSum(a, b) + multiplication(a, b);
    F. Current Limitations:
    As happy as I am to share this work with the B4x community, let's not forget that this is just my own internal tool, a never ending work-in-progress personal project.
    Hence, it does not yet support several features such as passing Arrays into the native layer.
    G. Reminder:
    Please test your C/C++ code before trying to build a B4A library, as some kinds of syntax errors may crash the application.

    Attached Files:

    Last edited: Nov 13, 2018
  2. sorex

    sorex Expert Licensed User

    Nice, wonder.

    Do you have some comparison sheet handy of several routines (grid scanners, math, whatever) that shows the speed gain compared to their 'real' B4A variant?
  3. wonder

    wonder Expert Licensed User

    So far, Informatix's maze solving algorithm seems to be faster, but due to its complexity there are still unresolved bugs/issues.
    The functions provided in the included example are slightly faster, but the real performance gain comes from writing heavy/complex functions natively.
  4. Stefano D'Andrea

    Stefano D'Andrea New Member Licensed User

    Wonderful work wonder, I'm noobs in Android and B4A. I've thousand and thousand lines of C code and your tool is perfect for me.

    I've tried your tool (differend configuration path for NDK and SLC) but i received the following error (slc dump)

    Simple Library CompilerC:\Users\stefano\Desktop\Native Library Generator\workspace>LibraryCompiler NinjaCore C:\Users\stefano\Desktop\Native Library Generator\project
    Wrong number of arguments. 2 arguments are expected (library name and project path).Simple Library CompilerC:\Users\stefano\Desktop\Native Library Generator\workspace>LibraryCompiler NinjaCore C:\Users\stefano\Desktop\Native Library Generator\project

    do you have any idea ?
  5. Stefano D'Andrea

    Stefano D'Andrea New Member Licensed User

    I've changed the name of "Native Library Generator" directory in "NativeLibraryGenerator" and i received

    [08:51:59]SLC compilation FAILED.
    [08:51:59] Run 'workspace\slc.bat' to see what went wrong.SLC compilation FAILED.

    but the library was built and saved in

    my conf is :

    Name: NinjaCore
    Author: Bruno Silva
    Version: 1.01
    [SLC] C:\Programmi\Anywhere Software\SimpleLibraryCompiler
    [NDK] C:\Users\stefano\Downloads\android-ndk-r10e
    [LIB] C:\Android\B4AExternalLibs
    Package: com.ninjadynamics.ninjacore
  6. wonder

    wonder Expert Licensed User

    @Stefano D'Andrea Thanks for the report. :)
    I'll try to replicate your steps in order to generate the same error.

    Which folder are you using to store your B4A external libs? In other words, does this [C:\Android\B4AExternalLibs] folder exist in your computer?
    Last edited: Jan 10, 2016
  7. Erel

    Erel Administrator Staff Member Licensed User

    It fails here. I think that it looks for the NDK in a non-existent folder.
  8. wonder

    wonder Expert Licensed User

    The SLC compilation will only (attempt) to if the NDK compile was successful.
    This means that the NDK-Build was completed without problems. It's probably a configuration issue.

    This folder [C:\Android\B4AExternalLibs] is the folder I use on my PC to store the B4A external libs, see screenshot.

    Last edited: Jan 10, 2016
  9. wonder

    wonder Expert Licensed User

    @Erel, Ok, I got it! :)

    Provided all the correct paths, I've tried to run my program from a folder called "New Folder".
    Upon compilation, SLC.bat does the following:
    LibraryCompiler TestLib C:\Users\Bruno\Desktop\New Folder
    Because I forgot the quotes, SLC interprets "Folder" as a 3rd argument and we get the error:
    Wrong number of arguments. 2 arguments are expected (library name and project path).

    This is easily solved by adding quotes:
    LibraryCompiler TestLib "C:\Users\Bruno\Desktop\New Folder"

    Bug corrected. Please download Native Library Generator again.
    Last edited: Jan 10, 2016
  10. Erel

    Erel Administrator Staff Member Licensed User

    Works perfectly!

    Great job!

    BTW, how did you create this form theme (the custom title bar)?
    wonder likes this.
  11. wonder

    wonder Expert Licensed User

    Thank you so much!! :D

    Actually, there is no title bar. It's just a colored label simulating it. ;)

    MainForm = Form1
    MainForm.Title = 
    "[C++] Native Library Generator"
    MainForm.Resizable = 
    File.GetUri(File.DirAssets, "style.css"))
    MainForm.RootPane.Style = 
    "-fx-background-color: rgba(48, 48, 48, 1); -fx-border-color: rgba(64, 64, 64, 1);"

    Dim w = MainForm.Width  As Int
    Dim h = MainForm.Height As Int

    File.DirAssets, "Consolas.ttf"12)

    lblTitle.Style = 
    "-fx-vertical-align: text-top; -fx-font: 12px Consolas; -fx-text-fill: rgba(0, 192, 255, 1); -fx-background-color: rgba(40, 40, 40, 1);"
    lblTitle.Text = 
    " [C++] Native Library Generator"
    11, w - 2, h * 0.05)

    lblExit.Style = 
    "-fx-vertical-align: text-top; -fx-font: 12px Consolas; -fx-text-fill: rgba(0, 192, 255, 1); -fx-background-color: rgba(40, 40, 40, 1);"
    lblExit.Text = 
    "X "
    MainForm.RootPane.AddNode(lblExit, w - 
    20119, h * 0.05)

    lblSound.Style = 
    "-fx-vertical-align: text-top; -fx-font: 12px Consolas; -fx-text-fill: rgba(0, 192, 255, 1); -fx-background-color: rgba(40, 40, 40, 1);"
    lblSound.Text = 
    MainForm.RootPane.AddNode(lblSound, w - 
    50119, h * 0.05)  

    txtConfgBox.Style = 
    "-fx-vertical-align: text-top; -fx-font: 12px Consolas; -fx-text-fill: rgba(255, 192, 0, 1); -fx-border-color: rgba(0, 192, 255, 1); -fx-background-color: black; -fx-border-radius: 3px;"
    MainForm.RootPane.AddNode(txtConfgBox, w * 
    0.05, h * 0.10, w * 0.50, h * 0.21)

    txtStatsBox.Style = 
    "-fx-vertical-align: text-top; -fx-font: 12px Consolas; -fx-text-fill: rgba(0, 192, 255, 1); -fx-border-color: rgba(0, 192, 255, 1); -fx-background-color: black; -fx-border-radius: 3px;"
    txtStatsBox.Text  = 
    ":: [C++] Native Library Generator" & CRLF & _                      
    ":: 2015-2016 Bruno Silva / Ninja Dynamics" & CRLF & _
    ":: Music: Kenny Chou - One Must Fall: 2097 " & CRLF & _                  
    CRLF & CRLF & CRLF & _
    "[" & DateTime.Time(DateTime.Now) & "] Ready." & CRLF
    txtStatsBox.WrapText = 
    txtStatsBox.Editable = 
    MainForm.RootPane.AddNode(txtStatsBox, w * 
    0.57, h * 0.10, w * 0.38, h * 0.21)

    txtPasteBox.Style = 
    "-fx-vertical-align: text-top; -fx-font: 12px Consolas; -fx-text-fill: rgba(0, 255, 64, 255); -fx-border-color: rgba(0, 192, 255, 1); -fx-background-color: transparent; -fx-border-radius: 3px;"
    MainForm.RootPane.AddNode(txtPasteBox, w * 
    0.05, h * 0.345, w * 0.90, h * 0.455)      

    btnGo.Text = 
    "Generate B4A Library"
    btnGo.Style = btnGo.Style & 
    "-fx-background-color:  rgba(0, 182, 255, 1);"
    MainForm.RootPane.AddNode(btnGo, w * 
    0.05, h * 0.85, w * 0.90, h * 0.10)
    "bgMusic"File.GetUri(File.DirAssets, "music.mp3"))
    bgMusic.Volume = 
    bgMusic.CycleCount = -
    As you can see, I like to do everything in code, didn't use the designer a single time. :)
    Last edited: Jan 10, 2016
    KZero, fireday and Erel like this.
  12. Stefano D'Andrea

    Stefano D'Andrea New Member Licensed User

    Thank you wonder the problem is the folder [C:\Android\B4AExternalLibs]
    it exists but it is not the extra lib configuration path of B4A.

    p.S: The update version works fine. Thank you
    wonder likes this.
  13. Erel

    Erel Administrator Staff Member Licensed User

    The designer could have helped you with making the layout resizable.
    wonder likes this.
  14. wonder

    wonder Expert Licensed User

    - Example source code updated. Bugs corrected. See section C.
    - Now supporting C++ headers, such as <vector> or <algorithm>
    Last edited: Jan 20, 2016
    fireday likes this.
  15. wonder

    wonder Expert Licensed User

    - Now supporting simple C/C++ typedef structures.
    - Now supporting C/C++ inline functions (see Section C on the first post).
    - Minor bug fixes.
    Last edited: Jan 20, 2016
    fireday likes this.
  16. Roberto P.

    Roberto P. Well-Known Member Licensed User

    Hello Wonder
    I really like your project (because I know better and I prefer C ++ to Java), but I can not understand how it can be used in the development of applications for Android ?! Rather, what features we can develop more or better than Java \ B4A? Knowing a bit architecture of Android, so that we can access a lower level, but I do not know what we can do.
    Thanks a lot
  17. wonder

    wonder Expert Licensed User

    Hello hello!

    Many thanks for your interest in my project. :)
    The greatest advantage of writing native-base code is the major speed improvement over Java.
    Of course, the native code always has to be well-structured by the developer, otherwise the advantages might be minimal or none at all.

    A good example would be the MazeSolver library I'm currently working on.
    With @Informatix's help we've done some benchmarking. The C++ version runs about 30% faster than it's Java counterpart.

    Here's some practical possible implementations:
    - Videogames
    - Path-finding for GPS/Navigation apps
    - Physics Engines
    - High-Frequency Trading
    - Genetic Algorithms
    - Neural Networks
    - Encryption Breaking Algorithms
    - Scientific Research (requiring heavy math computations)
    - Real-time Image Processing
    - Augmented Reality
    - Face recognition
    - Video Processing
    - Audio Processing
    - Protein Folding Algorithms
    fireday likes this.
  18. Roberto P.

    Roberto P. Well-Known Member Licensed User

    Thank you for the explanation. I understand. Projects based on performance, that only c / C ++ can give (the king of languages). Of all could care functionality GPS / Navigation apps. I'll watch your message.
  19. wonder

    wonder Expert Licensed User

    No problem. :)

    Regarding a GPS/Nav app, the real advantage would come from having your own maps and developing your own Path Finding algorithm (turn-by-turn) navigation, at least in theory.

    As a proof-of-concept, I'll try to map my neighborhood in MS-Paint, convert it into a 2-bit dot-matrix and apply my current MazeSolver lib to see if it helps me navigate the real world, in real-time. ;)
    fireday likes this.
  20. Roberto P.

    Roberto P. Well-Known Member Licensed User

    it would be great to have such aid to developing a good management system turns on maps. It is required, but is complex to develop.
    I hope you do something about this.
    thank you
    wonder likes this.
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