Adapt Official Ogre Tutorial Framework for iPhone(iOS)

The official Ogre Tutorial Framework doesn't work on iPhone. So we need to tweak it so it can run on iPhone. This guide walks you through for it and tries to minimize the modification to the original.
I believe you have done through to the 6th task in the prerequisite guide for setting up the environment of XCode 4.3. This guide works through by fixing compiler errors in that environment. The 6th task has added the official Ogre Tutorial Framework files to your new project you are currently working on. There should be no include errors. If so, you have to check your include paths.
Green lines of code mean you have to add them. Struck red lines of code mean you have to remove them from the original code.

1. Let's include necessary header files.
   For a start, open BaseApplication.h. Define the constant OGRE_STATIC_GLES and include the three headers: OgreStaticPluginLoader.h, OISMultiTouch.h, macUtils.h as following.

   #ifndef __BaseApplication_h_
   #define __BaseApplication_h_
   
   #define OGRE_STATIC_GLES 1
   
   #include <OgreCamera.h>
   #include <OgreEntity.h>
   #include <OgreLogManager.h>
   #include <OgreRoot.h>
   #include <OgreViewport.h>
   #include <OgreSceneManager.h>
   #include <OgreRenderWindow.h>
   #include <OgreConfigFile.h>
   #include <OgreStaticPluginLoader.h>
   
   #include <OISEvents.h>
   #include <OISInputManager.h>
   #include <OISKeyboard.h>
   #include <OISMouse.h>
   #include <OISMultiTouch.h>
   
   #include <SdkTrays.h>
   #include <SdkCameraMan.h>
   #include <macUtils.h>
   



2. Clear out the code inside the body of BaseApplication::windowResized() and remove main() in TutorialApplication.cpp.


3. Let's deal with multitouch code.
   We are going to use [Find and Replace in Workspace...] in the main menu Edit-Find. Don't ignore case. Make sure you search only in this project.
   
   • Replace OISMouse with OISMultiTouch.
   • Replace MouseEvent with MultiTouchEvent.
   • Replace MouseListener with MultiTouchListener.
   • Change the method names mouseMoved(), mousePressed(), mouseReleased() in class BaseApplication respectively to touchMoved(), touchPressed(), touchReleased() and remove the last parameter OIS::MouseButtonID id from touchPressed(), touchReleased(). We should accordingly modify both the declarations and the implementations. The calls to injectMouseDown() and injectMouseUp() also require removal of the 'id' parameters.
   • Add touchCancelled() to class BaseApplication.

     virtual bool touchCancelled( const OIS::MultiTouchEvent& evt )
     { return true ; }
     

   • Replace OIS::Mouse with OIS::MultiTouch.


4. At this point in the simulator mode you get to see only link errors. If you don't like them, set up the linking libraries by doing the 7th task of the prerequisite guide. but you can keep going with this guide.


5. Let's remove the code related with the keyboard.
   Comment out the variable mKeyboard in class BaseApplication and handle the entailed compiler errors by commenting them out.


6. Let's revise the code of starting-up and cleaning-up.
   To begin with, add the next variable to class BaseApplication.

   Ogre::StaticPluginLoader m_StaticPluginLoader ;
   

   Now modify go(), setup(), the destructor of class BaseApplication as following.

   void BaseApplication::go(void)
   {
   #ifdef _DEBUG
       mResourcesCfg = "resources_d.cfg";
       mPluginsCfg = "plugins_d.cfg";
   #else
       mResourcesCfg = "resources.cfg";
       mPluginsCfg = "plugins.cfg";
   #endif
   
       if (!setup())
           return;
   
       mRoot->startRendering();
   
       // clean up
       destroyScene();
   }

   
   

   bool BaseApplication::setup(void)
   {
       mResourcesCfg = Ogre::macBundlePath() + "/resources.cfg";
       mPluginsCfg = "plugins.cfg";
   
       mRoot = new Ogre::Root(mPluginsCfg);
       m_StaticPluginLoader.load() ;
   
       setupResources();
   
   ...

   
   

   BaseApplication::~BaseApplication(void)
   {
       if (mTrayMgr) delete mTrayMgr;
       if (mCameraMan) delete mCameraMan;
   
       //Remove ourself as a Window listener
       Ogre::WindowEventUtilities::removeWindowEventListener(mWindow, this);
       windowClosed(mWindow);
       delete mRoot;
       m_StaticPluginLoader.unload();
   }



7. Let's modify BaseApplication::setupResource()
   Relative paths don't work in iOS. So we attach the bundle path as prefix to them. Don't miss the second addition 'bunPath +'
   

   void BaseApplication::setupResources(void)
   {
       // Load resource paths from config file
       Ogre::ConfigFile cf;
       cf.load(mResourcesCfg);
   
       // Go through all sections & settings in the file
       Ogre::ConfigFile::SectionIterator seci = cf.getSectionIterator();
   
       Ogre::String bunPath = Ogre::macBundlePath() + "/" ;
       Ogre::String secName, typeName, archName;
       while (seci.hasMoreElements())
       {
           secName = seci.peekNextKey();
           Ogre::ConfigFile::SettingsMultiMap *settings = seci.getNext();
           Ogre::ConfigFile::SettingsMultiMap::iterator i;
           for (i = settings->begin(); i != settings->end(); ++i)
           {
               typeName = i->first;
               archName = bunPath + i->second;
               Ogre::ResourceGroupManager::getSingleton().addResourceLocation(
                   archName, typeName, secName);
           }
       }
   }



8. Let's modify accessibility to class BaseApplication.
   Make setup() and destroyScene() public and add an inline function get_Root() which allows access to Ogre's root object.

   ...
       virtual ~BaseApplication(void);
    
       virtual void go(void);
   protected:
       virtual bool setup();
       virtual void destroyScene(void);
       Ogre::Root* get_pRoot() const { return mRoot ; }
       
   protected:
       virtual bool configure(void);
       virtual void chooseSceneManager(void);
       virtual void createCamera(void);
       virtual void createFrameListener(void);
       virtual void createScene(void) = 0; // Override me!
       virtual void destroyScene(void);
       virtual void createViewports(void);
   ...
   



9. This is optional but this will make the camera naturally move along a touch on the screen.
   Add the next line to the end of BaseApplication::createCamera() method.

       mCameraMan->setStyle( OgreBites::CS_ORBIT ) ;
   

   The camera will orbit the origin point (0,0,0). Don't forget that this camera movement is really restricted. Later you can set a different style like CS_MANUAL for maximum freedom.