Irrlicht 3D Engine: Tutorial 17: Helloworld mobile

| Irrlicht 3D Engine |

Tutorial 17: Helloworld mobile
This example show Hello World for Windows mobile. It compiles on other platform too. The only differences between the original examples are. You need a GUI, because otherwise you can't quit the application. You need a Filesystem, which is relative based to your executable.

    #include <irrlicht.h>

    #if defined ( _IRR_WINDOWS_ )
        #include <windows.h>
    #endif

    using namespace irr;
    using namespace core;
    using namespace scene;
    using namespace video;
    using namespace io;
    using namespace gui;

    #pragma comment(lib, "Irrlicht.lib")

    class EventReceiver_basic : public IEventReceiver
    {
    private:
        IrrlichtDevice *Device;
    public:
        EventReceiver_basic ( IrrlichtDevice *device ): Device ( device ) {}

        virtual bool OnEvent(const SEvent& event)
        {
            if (event.EventType == EET_GUI_EVENT)
            {
                s32 id = event.GUIEvent.Caller->getID();

                switch(event.GUIEvent.EventType)
                {
                    case EGET_BUTTON_CLICKED:
                    if (id == 2)
                    {
                        Device->closeDevice();
                        return true;
                    } break;
                }
            }

            return false;
        }
    };

    class CSampleSceneNode : public ISceneNode
    {
        aabbox3d<f32> Box;
        S3DVertex Vertices[4];
        SMaterial Material;
    public:

        CSampleSceneNode(ISceneNode* parent, ISceneManager* mgr, s32 id)
            : ISceneNode(parent, mgr, id)
        {
            Material.Wireframe = false;
            Material.Lighting = false;

            Vertices[0] = S3DVertex(0,0,10, 1,1,0, SColor(255,0,255,255), 0, 1);
            Vertices[1] = S3DVertex(10,0,-10, 1,0,0, SColor(255,255,0,255), 1, 1);
            Vertices[2] = S3DVertex(0,20,0, 0,1,1, SColor(255,255,255,0), 1, 0);
            Vertices[3] = S3DVertex(-10,0,-10, 0,0,1, SColor(255,0,255,0), 0, 0);
            Box.reset(Vertices[0].Pos);
            for (s32 i=1; i<4; ++i)
                Box.addInternalPoint(Vertices[i].Pos);
        }
        virtual void OnRegisterSceneNode()
        {
            if (IsVisible)
                SceneManager->registerNodeForRendering(this);

            ISceneNode::OnRegisterSceneNode();
        }

        virtual void render()
        {
            u16 indices[] = {   0,2,3, 2,1,3, 1,0,3, 2,0,1  };
            IVideoDriver* driver = SceneManager->getVideoDriver();

            driver->setMaterial(Material);
            driver->setTransform(ETS_WORLD, AbsoluteTransformation);
            driver->drawIndexedTriangleList(&Vertices[0], 4, &indices[0], 4);
        }

        virtual const aabbox3d<f32>& getBoundingBox() const
        {
            return Box;
        }

        virtual u32 getMaterialCount()
        {
            return 1;
        }

        virtual SMaterial& getMaterial(u32 i)
        {
            return Material;
        }
    };

! Startup a Windows Mobile Device

    IrrlichtDevice *startup()
    {
        // both software and burnings video can be used
        E_DRIVER_TYPE driverType = EDT_SOFTWARE; // EDT_BURNINGSVIDEO;

        // create device
        IrrlichtDevice *device = 0;

    #if defined (_IRR_USE_WINDOWS_CE_DEVICE_)
        // set to standard mobile fullscreen 240x320
        device = createDevice(driverType, dimension2d<u32>(240, 320), 16, true );
    #else
        // on PC. use window mode
        device = createDevice(driverType, dimension2d<u32>(240, 320), 16, false );
    #endif
        if ( 0 == device )
            return 0;

        IVideoDriver* driver = device->getVideoDriver();
        ISceneManager* smgr = device->getSceneManager();
        IGUIEnvironment* guienv = device->getGUIEnvironment();

        // set the filesystem relative to the executable
    #if defined (_IRR_WINDOWS_)
        {
            wchar_t buf[255];
            GetModuleFileNameW ( 0, buf, 255 );

            io::path base = buf;
            base = base.subString ( 0, base.findLast ( '\\' ) + 1 );
            device->getFileSystem()->addFileArchive ( base );
        }
    #endif

        IGUIStaticText *text = guienv->addStaticText(L"FPS: 25",
            rect<s32>(140,15,200,30), false, false, 0, 100 );

        guienv->addButton(core::rect<int>(200,10,238,30), 0, 2, L"Quit");

        // add irrlicht logo
        guienv->addImage(driver->getTexture("../../media/irrlichtlogo3.png"),
                        core::position2d<s32>(0,-2));
        return device;
    }

!

    int run ( IrrlichtDevice *device )
    {
        while(device->run())
        if (device->isWindowActive())
        {
            device->getVideoDriver()->beginScene(true, true, SColor(0,100,100,100));
            device->getSceneManager()->drawAll();
            device->getGUIEnvironment()->drawAll();
            device->getVideoDriver()->endScene ();

            IGUIElement *stat = device->getGUIEnvironment()->
                getRootGUIElement()->getElementFromId ( 100 );
            if ( stat )
            {
                stringw str = L"FPS: ";
                str += (s32)device->getVideoDriver()->getFPS();

                stat->setText ( str.c_str() );
            }
        }

        device->drop();
        return 0;
    }

!

    int example_customscenenode()
    {
        // create device
        IrrlichtDevice *device = startup();
        if (device == 0)
            return 1; // could not create selected driver.

        // create engine and camera
        EventReceiver_basic receiver(device);
        device->setEventReceiver(&receiver);

        IVideoDriver* driver = device->getVideoDriver();
        ISceneManager* smgr = device->getSceneManager();
        IGUIEnvironment* guienv = device->getGUIEnvironment();

        smgr->addCameraSceneNode(0, vector3df(0,-40,0), vector3df(0,0,0));

        CSampleSceneNode *myNode =
            new CSampleSceneNode(smgr->getRootSceneNode(), smgr, 666);

        ISceneNodeAnimator* anim =
            smgr->createRotationAnimator(vector3df(0.8f, 0, 0.8f));

        if(anim)
        {
            myNode->addAnimator(anim);
            anim->drop();
            anim = 0; // As I shouldn't refer to it again, ensure that I can't
        }

        myNode->drop();
        myNode = 0; // As I shouldn't refer to it again, ensure that I can't

        return run ( device );
    }

    class EventReceiver_terrain : public IEventReceiver
    {
    public:

        EventReceiver_terrain(IrrlichtDevice *device, scene::ISceneNode* terrain, scene::ISceneNode* skybox, scene::ISceneNode* skydome) :
            Device ( device ), Terrain(terrain), Skybox(skybox), Skydome(skydome), showBox(true)
        {
            Skybox->setVisible(true);
            Skydome->setVisible(false);
        }

        bool OnEvent(const SEvent& event)
        {
            if (event.EventType == EET_GUI_EVENT)
            {
                s32 id = event.GUIEvent.Caller->getID();

                switch(event.GUIEvent.EventType)
                {
                    case EGET_BUTTON_CLICKED:
                    if (id == 2)
                    {
                        Device->closeDevice();
                        return true;
                    } break;
                }
            }

            // check if user presses the key 'W' or 'D'
            if (event.EventType == irr::EET_KEY_INPUT_EVENT && !event.KeyInput.PressedDown)
            {
                switch (event.KeyInput.Key)
                {
                case irr::KEY_KEY_W: // switch wire frame mode
                    Terrain->setMaterialFlag(video::EMF_WIREFRAME,
                            !Terrain->getMaterial(0).Wireframe);
                    Terrain->setMaterialFlag(video::EMF_POINTCLOUD, false);
                    return true;
                case irr::KEY_KEY_P: // switch wire frame mode
                    Terrain->setMaterialFlag(video::EMF_POINTCLOUD,
                            !Terrain->getMaterial(0).PointCloud);
                    Terrain->setMaterialFlag(video::EMF_WIREFRAME, false);
                    return true;
                case irr::KEY_KEY_D: // toggle detail map
                    Terrain->setMaterialType(
                        Terrain->getMaterial(0).MaterialType == video::EMT_SOLID ?
                        video::EMT_DETAIL_MAP : video::EMT_SOLID);
                    return true;
                case irr::KEY_KEY_S: // toggle skies
                    showBox=!showBox;
                    Skybox->setVisible(showBox);
                    Skydome->setVisible(!showBox);
                    return true;
                default:
                    break;
                }
            }

            return false;
        }

    private:
        IrrlichtDevice *Device;
        scene::ISceneNode* Terrain;
        scene::ISceneNode* Skybox;
        scene::ISceneNode* Skydome;
        bool showBox;
    };

The start of the main function starts like in most other example. We ask the user for the desired renderer and start it up. This time with the advanced parameter handling.

    int example_terrain()
    {
        // create device
        IrrlichtDevice *device = startup();
        if (device == 0)
            return 1; // could not create selected driver.

First, we add standard stuff to the scene: A nice irrlicht engine logo, a small help text, a user controlled camera, and we disable the mouse cursor.

        video::IVideoDriver* driver = device->getVideoDriver();
        scene::ISceneManager* smgr = device->getSceneManager();
        gui::IGUIEnvironment* env = device->getGUIEnvironment();

        //set other font
        //env->getSkin()->setFont(env->getFont("../../media/fontlucida.png"));

        // add some help text
        env->addStaticText(
            L"Press 'W' to change wireframe mode\nPress 'D' to toggle detail map\nPress 'S' to toggle skybox/skydome",
            core::rect<s32>(5,250,235,320), true, true, 0, -1, true);

        // add camera
        scene::ICameraSceneNode* camera =
            smgr->addCameraSceneNodeFPS(0,100.0f,1.2f);

        camera->setPosition(core::vector3df(2700*2,255*2,2600*2));
        camera->setTarget(core::vector3df(2397*2,343*2,2700*2));
        camera->setFarValue(42000.0f);

        // disable mouse cursor
        device->getCursorControl()->setVisible(false);

Here comes the terrain renderer scene node: We add it just like any other scene node to the scene using ISceneManager::addTerrainSceneNode(). The only parameter we use is a file name to the heightmap we use. A heightmap is simply a gray scale texture. The terrain renderer loads it and creates the 3D terrain from it.

To make the terrain look more big, we change the scale factor of it to (40, 4.4, 40). Because we don't have any dynamic lights in the scene, we switch off the lighting, and we set the file terrain-texture.jpg as texture for the terrain and detailmap3.jpg as second texture, called detail map. At last, we set the scale values for the texture: The first texture will be repeated only one time over the whole terrain, and the second one (detail map) 20 times.

        // add terrain scene node
        scene::ITerrainSceneNode* terrain = smgr->addTerrainSceneNode(
            "../../media/terrain-heightmap.bmp",
            0,                  // parent node
            -1,                 // node id
            core::vector3df(0.f, 0.f, 0.f),     // position
            core::vector3df(0.f, 0.f, 0.f),     // rotation
            core::vector3df(40.f, 4.4f, 40.f),  // scale
            video::SColor ( 255, 255, 255, 255 ),   // vertexColor
            5,                  // maxLOD
            scene::ETPS_17,             // patchSize
            4                   // smoothFactor
            );

        if ( terrain )
        {
            terrain->setMaterialFlag(video::EMF_LIGHTING, false);

            terrain->setMaterialTexture(0,
                    driver->getTexture("../../media/terrain-texture.jpg"));
            terrain->setMaterialTexture(1,
                    driver->getTexture("../../media/detailmap3.jpg"));

            terrain->setMaterialType(video::EMT_DETAIL_MAP);

            terrain->scaleTexture(1.0f, 20.0f);
            //terrain->setDebugDataVisible ( true );

To be able to do collision with the terrain, we create a triangle selector. If you want to know what triangle selectors do, just take a look into the collision tutorial. The terrain triangle selector works together with the terrain. To demonstrate this, we create a collision response animator and attach it to the camera, so that the camera will not be able to fly through the terrain.

            // create triangle selector for the terrain
            scene::ITriangleSelector* selector
                = smgr->createTerrainTriangleSelector(terrain, 0);
            terrain->setTriangleSelector(selector);

            // create collision response animator and attach it to the camera
            scene::ISceneNodeAnimator* anim = smgr->createCollisionResponseAnimator(
                selector, camera, core::vector3df(60,100,60),
                core::vector3df(0,0,0),
                core::vector3df(0,50,0));
            selector->drop();
            camera->addAnimator(anim);
            anim->drop();

If you need access to the terrain data you can also do this directly via the following code fragment.

            scene::CDynamicMeshBuffer* buffer = new scene::CDynamicMeshBuffer(video::EVT_2TCOORDS, video::EIT_16BIT);
            terrain->getMeshBufferForLOD(*buffer, 0);
            video::S3DVertex2TCoords* data = (video::S3DVertex2TCoords*)buffer->getVertexBuffer().getData();
            // Work on data or get the IndexBuffer with a similar call.
            buffer->drop(); // When done drop the buffer again.
        }

To make the user be able to switch between normal and wireframe mode, we create an instance of the event receiver from above and let Irrlicht know about it. In addition, we add the skybox which we already used in lots of Irrlicht examples and a skydome, which is shown mutually exclusive with the skybox by pressing 'S'.

        // create skybox and skydome
        driver->setTextureCreationFlag(video::ETCF_CREATE_MIP_MAPS, false);

        scene::ISceneNode* skybox=smgr->addSkyBoxSceneNode(
            driver->getTexture("../../media/irrlicht2_up.jpg"),
            driver->getTexture("../../media/irrlicht2_dn.jpg"),
            driver->getTexture("../../media/irrlicht2_lf.jpg"),
            driver->getTexture("../../media/irrlicht2_rt.jpg"),
            driver->getTexture("../../media/irrlicht2_ft.jpg"),
            driver->getTexture("../../media/irrlicht2_bk.jpg"));
        scene::ISceneNode* skydome=smgr->addSkyDomeSceneNode(driver->getTexture("../../media/skydome.jpg"),16,8,0.95f,2.0f);

        driver->setTextureCreationFlag(video::ETCF_CREATE_MIP_MAPS, true);

        // create event receiver
        EventReceiver_terrain receiver( device, terrain, skybox, skydome);
        device->setEventReceiver(&receiver);

        return run ( device );
    }

    int example_helloworld()
    {
        // create device
        IrrlichtDevice *device = startup();
        if (device == 0)
            return 1; // could not create selected driver.

        IVideoDriver* driver = device->getVideoDriver();
        ISceneManager* smgr = device->getSceneManager();
        IGUIEnvironment* guienv = device->getGUIEnvironment();

        IAnimatedMesh* mesh = smgr->getMesh("../../media/sydney.md2");
        if (!mesh)
        {
            device->drop();
            return 1;
        }
        IAnimatedMeshSceneNode* node = smgr->addAnimatedMeshSceneNode( mesh );

To let the mesh look a little bit nicer, we change its material. We disable lighting because we do not have a dynamic light in here, and the mesh would be totally black otherwise. Then we set the frame loop, such that the predefined STAND animation is used. And last, we apply a texture to the mesh. Without it the mesh would be drawn using only a color.

        if (node)
        {
            node->setMaterialFlag(EMF_LIGHTING, false);
            node->setMD2Animation(scene::EMAT_STAND);
            node->setMaterialTexture( 0, driver->getTexture("../../media/sydney.bmp") );
        }

To look at the mesh, we place a camera into 3d space at the position (0, 30, -40). The camera looks from there to (0,5,0), which is approximately the place where our md2 model is.

        smgr->addCameraSceneNode(0, vector3df(0,30,-40), vector3df(0,5,0));

        EventReceiver_basic receiver(device);
        device->setEventReceiver(&receiver);

        return run ( device );

    }

    #if defined (_IRR_USE_WINDOWS_CE_DEVICE_)
        #pragma comment(linker, "/subsystem:WINDOWSCE /ENTRY:main")
    #elif defined (_IRR_WINDOWS_)
        #pragma comment(linker, "/subsystem:windows /ENTRY:mainCRTStartup")
    #endif

    int main()
    {
        example_helloworld ();
        example_customscenenode();
        //example_terrain();
    }