Introduction: Compiler and Developement Environment


This tutorial will teach the reader how to use -Lua and LuaBind in a simple Ogre application created using the Code::Blocks' development environment.

If you use VC++7 (or more) and it's dev. env., you can directly use the project files provided in this tutorial.

Note: To use this tutorial you'll need reasonable experience with C++ and Ogre. If you are not ready for this tutorial then find one that's appropriate. If you're an experienced LuaBind user then you won't benefit from this simple tutorial either.


Downloading and Installing the Required Libraries


Our project will be based on 3 free libraries :

  1. Boost 1.33.1 - This library is required by LuaBind. Though some applications might require you to compile Boost the header files will be enough for this project.
  2. Lua 5.1.1 - You'll probably need the Sources. Read below.
  3. LuaBind 0.7 - You'll probably need the Sources too.


Problem with Luabind's support of boost


As written in the "Nuclex tutorial", "changes in the Boost library have not been reflected in LuaBind yet". So, in order to be able to compile these three libraries together, you should "set up and compile each library as well as possibly modify LuaBind". This is what we are going to do to use Luabind inside Code::Blocks.

Nevertheless, "this whole process can be somewhat troublesome", so :

  1. Download directly the ready-to-use pack provided on the Nuclex website - You can download it directly by following this link.


As you can see, this pack already contains compiled -Lua and Luabind libraries (both static and dynamic), but unfortunately these libraries are meant to compile in an "VC8-friendly" developement environment, that means that for example you'd need the Windows SDK to add them to your project. It would be one more (heavy) SDK to download, this is why it's easier to recompile these libraries in a "pure Code::blocks" way (Code::Blocks with the MinGW compiler provide the minimum required files to compile Win32 applications without downloading the whole Windows SDK).

This is exactly what we are going to do. Read below.

Prerequisite : Creating an Ogre Project

  1. Run Code::Blocks, then use the wizard to create a new "Ogre3D project" that we will name myOgreProject. Run it.


If it doesn't run fine, then it means that you have a problem with your installation of Code::Blocks/the Ogre3D SDK/the DirectX SDK/whatever else. In this case, read the installation instructions again.

Add -Lua and Luabind projects to your Code::Blocks Solution


The goal of this step is to take advantage of Lua/Luabind/Boost's modified sources mentioned previously and to insert them in our solution as Code::Blocks projects instead of VC++8 projects.

Follow these instructions :

  1. Unpack the "Nuclex Pack" archive somewhere. It should be named luabind-binariesAndDemo if you kept the original name. We'll come back to this directory later.
  2. Unpack the library-sources.zip archive contained in the previous one. In the newly created folder, you should find a Visual Studio solution (.sln) and the three "modified" folders in which we find a so great interest : boost_1_33_1_lite, lua-5.1.1 and luabind.
  3. Copy the library-sources folder to your myOgreProject folder.


Creating the -Lua project :

  1. In myOgreProject\library-sources\lua-5.1.1\Build, create a CodeBlocks folder, just next to the MSVC8 folder. The location of our Code::Blocks project is not important, but it's nicer to keep the original directories structure ;-)
  2. Inside Code::blocks, Create a new project. In the list, choose the "Static library" project type. Name it lua-5.1.1. Place it at the location myOgreProject\library-sources\lua-5.1.1\Build\CodeBlocks. This new project should appear in your solution, under your myOgreProject project.
  3. Right-click on the lua-5.1.1 project and select "Add files...". Select all ".c" and ".h" files from the myOgreProject\library-sources\lua-5.1.1\src folder.
  4. Set the lua-5.1.1 project as the active project and compile it. It should compile well.


Creating the Luabind project :

  1. (same as above) In myOgreProject\library-sources\luabind\Build, create a CodeBlocks folder, just next to the MSVC8 folder.
  2. (same as above) Inside Code::blocks, Create a new project. In the list, choose the "Static library" project type. Name it luabind. Place it at the location myOgreProject\library-sources\bind\Build\CodeBlocks. This new project should appear in your solution, under your lua-5.1.1 project.
  3. (same as above) Right-click on the luabind project and select "Add files...". Select all ".cpp" files from the myOgreProject\library-sources\luabind\src folder.
  4. Right-click on the luabind project and select "Build Options". In the left pane, click on "luabind", so that your actions have effect on both "Release" and "Debug" configurations. Click on "Directories" pane, then on "Compiler" subpane. Click on "add" three times, to add these 3 folders :
* luabind
     * lua-5.1.1\src
     * boost_1_33_1_lite


Everytime, keep them as relative paths. Now, your luabind project know where to find the headers of these 3 projects. Click OK.

  1. Right-click on the luabind project and select "Properties...". Then click on "Project's dependencies". Select "luabind" and check "depends on lua-5.1.1". Click OK. Note : luabind doesn't really depend on lua but later the order of compilation will be important when we'll use both projects in our Ogre3D project.
  2. Set the luabind project as the active project and compile it. It should compile well.


If both compilations went well, you should now have two files :

* ''myOgreProject\library-sources\bind\Build\CodeBlocks\lua-5.1.1\obj\Debug\liblua-5.1.1.a''
     * ''myOgreProject\library-sources\bind\Build\CodeBlocks\luabind\obj\Debug\libluabind.a''

(replace Debug by Release if you compiled as Release)

Note that these libraries are named the Linux way. they are named "libxxxxxx.a" instead of "xxxxxx.lib", but they work anyway!

Reference lua and luabind static libraries in your Ogre3D project :

  1. Right-click on your myOgreProject and select "Build Options".
  2. In the left pane, select "Debug" (resp. "Release") and in the "link libraries" pane add the two files we mentioned above :
* ''myOgreProject\library-sources\bind\Build\CodeBlocks\lua-5.1.1\obj\Debug'''(resp. Release)'''\liblua-5.1.1.a''
     * ''myOgreProject\library-sources\bind\Build\CodeBlocks\luabind\obj\Debug'''(resp. Release)'''\libluabind.a''

Both libraries are now part of the project, but we don't use them yet, so in effect nothing has changed.

  1. Right-click on the myOgreProject project and select "Properties...". Then click on "Project's dependencies". Select "myOgreProject" and check "depends on luabind". Now, each project will be compiled in the right order for you to always have up-to-date libraries.


Enable Luabind in your project :

  1. In your myOgrePrject folder, create an Include folder.
  2. Now it's time to go back to your luabind-binariesAndDemo folder. Copy the contents of it's Include folder into your myOgreProject\Include folder. You now have the include files from lua, luabind and boost available in your project and they will travel with it if you move it. ;-)
  3. You may delete luabind-binariesAndDemo, you don't need it anymore.
  4. Inside Code::Blocks, right-click on the myOgreProject project and select "Build Options". In the left pane, click on "myOgreProject", so that your actions have effect on both "Release" and "Debug" configurations. Click on "Directories" pane, then on "Compiler" subpane. Click on "add" and add the myOgreProject\Include directory we created above, so that we didn't copy the include files for nothing ;-) Now, the compiler knows where to find them.
  5. Add this code at the top of your main.cpp file :
// Include the lua headers (the extern "C" is a requirement because we're
 // using C++ and lua has been compiled as C code)
 extern "C" {
   #include "lua/lua.h"
   #include "lua/lauxlib.h"
 }
 
 // This is the only header we need to include for LuaBind to work
 #include "luabind/luabind.hpp"

  1. In it's current state, compiling and running your program will run the Lua console, which is a bit intrusive! This happens if you are using the MigW compiler and linking to static libraries as described above, your workspace now contains multiple main() functions. Either explicitly comment out the WinMain() which gets generated by code::blocks's ogre3D wizard, or if you need to use windows.h, you can modify the code in main.cpp to look as follows (although I would also, alternatively, suggest you include windows.h in a common header file).:
// ----------------------------------------------------------------------------
 // Ogre Generated Main function, just boots the application object
 // ----------------------------------------------------------------------------
 #if OGRE_PLATFORM == OGRE_PLATFORM_WIN32
 #define WIN32_LEAN_AND_MEAN
 #include "windows.h"
 INT WINAPI WinMain( HINSTANCE hInst, HINSTANCE, LPSTR strCmdLine, INT );
 
 int main(int argc, char **argv)
 {
         return WinMain(GetModuleHandle(0),0,GetCommandLine(),0);
 }
 
 INT WINAPI WinMain( HINSTANCE hInst, HINSTANCE, LPSTR strCmdLine, INT )
 #else
 int main(int argc, char **argv)
 #endif


Note: If you just want to run your application as a console-style application, comment out the code related to OGRE_PLATFORM_WIN32 within your main.cpp file generated by code::blocks's ogre3D wizard.

Our project is now fully ready to welcome some luabind code!

Add a link to Lua's State:

  1. modify the following code block (created by default by code::blocks's ogre3D wizard) to add the luabind code :
try
    {
        lua_State *pMyLuaState = lua_open(); //Add this
        app.go();
        lua_close(pMyLuaState); //Add this too
    }


You can find explanations concerning this code in the next paragraph.

  1. Set the myOgreProject project as the active project and compile it. If it compiles well, then you're ready to code with lua and luabind !

How -Lua works

-Lua is used primarily through an object called a lua_State. This is Lua's virtual machine. It's somewhat like a seperate mini-program running within your application.

To use -Lua we need a pointer to our lua_State. It's pMyLuaState.

pMyLuaState= lua_open(); // initialize mLuaState for Lua


And now -Lua is initialized and ready to be given a .lua file to work with.

Shutting down -Lua is just as easy. Add this code to your deconstructor.

if( pMyLuaState)
 {
     lua_close(pMyLuaState);
     pMyLuaState= 0;
 }


Further coding in LUA


You should read these turorials:

  1. http://www.rasterbar.com/products/luabind/docs.html
  2. http://www.nuclex.org/articles/quick-introduction-to-luabind

See also



Alias: Scripting_with_LuaBind_in_Ogre

<HR>
Creative Commons Copyright -- Some rights reserved.


THE WORK (AS DEFINED BELOW) IS PROVIDED UNDER THE TERMS OF THIS CREATIVE COMMONS PUBLIC LICENSE ("CCPL" OR "LICENSE"). THE WORK IS PROTECTED BY COPYRIGHT AND/OR OTHER APPLICABLE LAW. ANY USE OF THE WORK OTHER THAN AS AUTHORIZED UNDER THIS LICENSE OR COPYRIGHT LAW IS PROHIBITED.

BY EXERCISING ANY RIGHTS TO THE WORK PROVIDED HERE, YOU ACCEPT AND AGREE TO BE BOUND BY THE TERMS OF THIS LICENSE. THE LICENSOR GRANTS YOU THE RIGHTS CONTAINED HERE IN CONSIDERATION OF YOUR ACCEPTANCE OF SUCH TERMS AND CONDITIONS.

1. Definitions

  • "Collective Work" means a work, such as a periodical issue, anthology or encyclopedia, in which the Work in its entirety in unmodified form, along with a number of other contributions, constituting separate and independent works in themselves, are assembled into a collective whole. A work that constitutes a Collective Work will not be considered a Derivative Work (as defined below) for the purposes of this License.
  • "Derivative Work" means a work based upon the Work or upon the Work and other pre-existing works, such as a translation, musical arrangement, dramatization, fictionalization, motion picture version, sound recording, art reproduction, abridgment, condensation, or any other form in which the Work may be recast, transformed, or adapted, except that a work that constitutes a Collective Work will not be considered a Derivative Work for the purpose of this License. For the avoidance of doubt, where the Work is a musical composition or sound recording, the synchronization of the Work in timed-relation with a moving image ("synching") will be considered a Derivative Work for the purpose of this License.
  • "Licensor" means the individual or entity that offers the Work under the terms of this License.
  • "Original Author" means the individual or entity who created the Work.
  • "Work" means the copyrightable work of authorship offered under the terms of this License.
  • "You" means an individual or entity exercising rights under this License who has not previously violated the terms of this License with respect to the Work, or who has received express permission from the Licensor to exercise rights under this License despite a previous violation.
  • "License Elements" means the following high-level license attributes as selected by Licensor and indicated in the title of this License: Attribution, ShareAlike.

2. Fair Use Rights

Nothing in this license is intended to reduce, limit, or restrict any rights arising from fair use, first sale or other limitations on the exclusive rights of the copyright owner under copyright law or other applicable laws.

3. License Grant

Subject to the terms and conditions of this License, Licensor hereby grants You a worldwide, royalty-free, non-exclusive, perpetual (for the duration of the applicable copyright) license to exercise the rights in the Work as stated below:

  • to reproduce the Work, to incorporate the Work into one or more Collective Works, and to reproduce the Work as incorporated in the Collective Works;
  • to create and reproduce Derivative Works;
  • to distribute copies or phonorecords of, display publicly, perform publicly, and perform publicly by means of a digital audio transmission the Work including as incorporated in Collective Works;
  • to distribute copies or phonorecords of, display publicly, perform publicly, and perform publicly by means of a digital audio transmission Derivative Works.
  • For the avoidance of doubt, where the work is a musical composition:
    • Performance Royalties Under Blanket Licenses. Licensor waives the exclusive right to collect, whether individually or via a performance rights society (e.g. ASCAP, BMI, SESAC), royalties for the public performance or public digital performance (e.g. webcast) of the Work.
    • Mechanical Rights and Statutory Royalties. Licensor waives the exclusive right to collect, whether individually or via a music rights society or designated agent (e.g. Harry Fox Agency), royalties for any phonorecord You create from the Work ("cover version") and distribute, subject to the compulsory license created by 17 USC Section 115 of the US Copyright Act (or the equivalent in other jurisdictions).
    • Webcasting Rights and Statutory Royalties. For the avoidance of doubt, where the Work is a sound recording, Licensor waives the exclusive right to collect, whether individually or via a performance-rights society (e.g. SoundExchange), royalties for the public digital performance (e.g. webcast) of the Work, subject to the compulsory license created by 17 USC Section 114 of the US Copyright Act (or the equivalent in other jurisdictions).


The above rights may be exercised in all media and formats whether now known or hereafter devised. The above rights include the right to make such modifications as are technically necessary to exercise the rights in other media and formats. All rights not expressly granted by Licensor are hereby reserved.

4. Restrictions

The license granted in Section 3 above is expressly made subject to and limited by the following restrictions:

  • You may distribute, publicly display, publicly perform, or publicly digitally perform the Work only under the terms of this License, and You must include a copy of, or the Uniform Resource Identifier for, this License with every copy or phonorecord of the Work You distribute, publicly display, publicly perform, or publicly digitally perform. You may not offer or impose any terms on the Work that alter or restrict the terms of this License or the recipients' exercise of the rights granted hereunder. You may not sublicense the Work. You must keep intact all notices that refer to this License and to the disclaimer of warranties. You may not distribute, publicly display, publicly perform, or publicly digitally perform the Work with any technological measures that control access or use of the Work in a manner inconsistent with the terms of this License Agreement. The above applies to the Work as incorporated in a Collective Work, but this does not require the Collective Work apart from the Work itself to be made subject to the terms of this License. If You create a Collective Work, upon notice from any Licensor You must, to the extent practicable, remove from the Collective Work any credit as required by clause 4(c), as requested. If You create a Derivative Work, upon notice from any Licensor You must, to the extent practicable, remove from the Derivative Work any credit as required by clause 4(c), as requested.
  • You may distribute, publicly display, publicly perform, or publicly digitally perform a Derivative Work only under the terms of this License, a later version of this License with the same License Elements as this License, or a Creative Commons iCommons license that contains the same License Elements as this License (e.g. Attribution-ShareAlike 2.5 Japan). You must include a copy of, or the Uniform Resource Identifier for, this License or other license specified in the previous sentence with every copy or phonorecord of each Derivative Work You distribute, publicly display, publicly perform, or publicly digitally perform. You may not offer or impose any terms on the Derivative Works that alter or restrict the terms of this License or the recipients' exercise of the rights granted hereunder, and You must keep intact all notices that refer to this License and to the disclaimer of warranties. You may not distribute, publicly display, publicly perform, or publicly digitally perform the Derivative Work with any technological measures that control access or use of the Work in a manner inconsistent with the terms of this License Agreement. The above applies to the Derivative Work as incorporated in a Collective Work, but this does not require the Collective Work apart from the Derivative Work itself to be made subject to the terms of this License.
  • If you distribute, publicly display, publicly perform, or publicly digitally perform the Work or any Derivative Works or Collective Works, You must keep intact all copyright notices for the Work and provide, reasonable to the medium or means You are utilizing: (i) the name of the Original Author (or pseudonym, if applicable) if supplied, and/or (ii) if the Original Author and/or Licensor designate another party or parties (e.g. a sponsor institute, publishing entity, journal) for attribution in Licensor's copyright notice, terms of service or by other reasonable means, the name of such party or parties; the title of the Work if supplied; to the extent reasonably practicable, the Uniform Resource Identifier, if any, that Licensor specifies to be associated with the Work, unless such URI does not refer to the copyright notice or licensing information for the Work; and in the case of a Derivative Work, a credit identifying the use of the Work in the Derivative Work (e.g., "French translation of the Work by Original Author," or "Screenplay based on original Work by Original Author"). Such credit may be implemented in any reasonable manner; provided, however, that in the case of a Derivative Work or Collective Work, at a minimum such credit will appear where any other comparable authorship credit appears and in a manner at least as prominent as such other comparable authorship credit.

5. Representations, Warranties and Disclaimer

UNLESS OTHERWISE AGREED TO BY THE PARTIES IN WRITING, LICENSOR OFFERS THE WORK AS-IS AND MAKES NO REPRESENTATIONS OR WARRANTIES OF ANY KIND CONCERNING THE MATERIALS, EXPRESS, IMPLIED, STATUTORY OR OTHERWISE, INCLUDING, WITHOUT LIMITATION, WARRANTIES OF TITLE, MERCHANTIBILITY, FITNESS FOR A PARTICULAR PURPOSE, NONINFRINGEMENT, OR THE ABSENCE OF LATENT OR OTHER DEFECTS, ACCURACY, OR THE PRESENCE OF ABSENCE OF ERRORS, WHETHER OR NOT DISCOVERABLE. SOME JURISDICTIONS DO NOT ALLOW THE EXCLUSION OF IMPLIED WARRANTIES, SO SUCH EXCLUSION MAY NOT APPLY TO YOU.

6. Limitation on Liability.

EXCEPT TO THE EXTENT REQUIRED BY APPLICABLE LAW, IN NO EVENT WILL LICENSOR BE LIABLE TO YOU ON ANY LEGAL THEORY FOR ANY SPECIAL, INCIDENTAL, CONSEQUENTIAL, PUNITIVE OR EXEMPLARY DAMAGES ARISING OUT OF THIS LICENSE OR THE USE OF THE WORK, EVEN IF LICENSOR HAS BEEN ADVISED OF THE POSSIBILITY OF SUCH DAMAGES.

7. Termination

  • This License and the rights granted hereunder will terminate automatically upon any breach by You of the terms of this License. Individuals or entities who have received Derivative Works or Collective Works from You under this License, however, will not have their licenses terminated provided such individuals or entities remain in full compliance with those licenses. Sections 1, 2, 5, 6, 7, and 8 will survive any termination of this License.
  • Subject to the above terms and conditions, the license granted here is perpetual (for the duration of the applicable copyright in the Work). Notwithstanding the above, Licensor reserves the right to release the Work under different license terms or to stop distributing the Work at any time; provided, however that any such election will not serve to withdraw this License (or any other license that has been, or is required to be, granted under the terms of this License), and this License will continue in full force and effect unless terminated as stated above.

8. Miscellaneous

  • Each time You distribute or publicly digitally perform the Work or a Collective Work, the Licensor offers to the recipient a license to the Work on the same terms and conditions as the license granted to You under this License.
  • Each time You distribute or publicly digitally perform a Derivative Work, Licensor offers to the recipient a license to the original Work on the same terms and conditions as the license granted to You under this License.
  • If any provision of this License is invalid or unenforceable under applicable law, it shall not affect the validity or enforceability of the remainder of the terms of this License, and without further action by the parties to this agreement, such provision shall be reformed to the minimum extent necessary to make such provision valid and enforceable.
  • No term or provision of this License shall be deemed waived and no breach consented to unless such waiver or consent shall be in writing and signed by the party to be charged with such waiver or consent.
  • This License constitutes the entire agreement between the parties with respect to the Work licensed here. There are no understandings, agreements or representations with respect to the Work not specified here. Licensor shall not be bound by any additional provisions that may appear in any communication from You. This License may not be modified without the mutual written agreement of the Licensor and You.