terrain.cpp

/** Example 012 Terrain Rendering



This tutorial will briefly show how to use the terrain renderer of Irrlicht. It

will also show the terrain renderer triangle selector to be able to do

collision detection with terrain.



Note that the Terrain Renderer in Irrlicht is based on Spintz'

GeoMipMapSceneNode, lots of thanks go to him. DeusXL provided a new elegant

simple solution for building larger area on small heightmaps -> terrain

smoothing.



In the beginning there is nothing special. We include the needed header files

and create an event listener to listen if the user presses a key: The 'W' key

switches to wireframe mode, the 'P' key to pointcloud mode, and the 'D' key

toggles between solid and detail mapped material.

*/

#include <irrlicht.h>

#include "driverChoice.h"



using namespace irr;



#ifdef _MSC_VER

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

#endif





class MyEventReceiver : public IEventReceiver

{

public:



	MyEventReceiver(scene::ISceneNode* terrain, scene::ISceneNode* skybox, scene::ISceneNode* skydome) :

		Terrain(terrain), Skybox(skybox), Skydome(skydome), showBox(true)

	{

		Skybox->setVisible(true);

		Skydome->setVisible(false);

	}



	bool OnEvent(const SEvent& event)

	{

		// 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:

	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 main()

{

	// ask user for driver

	video::E_DRIVER_TYPE driverType=driverChoiceConsole();

	if (driverType==video::EDT_COUNT)

		return 1;



	// create device with full flexibility over creation parameters

	// you can add more parameters if desired, check irr::SIrrlichtCreationParameters

	irr::SIrrlichtCreationParameters params;

	params.DriverType=driverType;

	params.WindowSize=core::dimension2d<u32>(640, 480);

	IrrlichtDevice* device = createDeviceEx(params);



	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();



	driver->setTextureCreationFlag(video::ETCF_ALWAYS_32_BIT, true);


	// 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>(10,421,250,475), 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(

		"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

		);



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



	terrain->setMaterialTexture(0,

			driver->getTexture("texture.bmp"));

	terrain->setMaterialTexture(1,

			driver->getTexture("texture.bmp"));

	

	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 reciever 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

	MyEventReceiver receiver(terrain, skybox, skydome);

	device->setEventReceiver(&receiver);



	/*

	That's it, draw everything.

	*/



	int lastFPS = -1;



	while(device->run())

	if (device->isWindowActive())

	{

		driver->beginScene(true, true, 0 );



		smgr->drawAll();

		env->drawAll();



		driver->endScene();



		// display frames per second in window title

		int fps = driver->getFPS();

		if (lastFPS != fps)

		{

			core::stringw str = L"Terrain Renderer - Irrlicht Engine [";

			str += driver->getName();

			str += "] FPS:";

			str += fps;

			// Also print terrain height of current camera position

			// We can use camera position because terrain is located at coordinate origin

			str += " Height: ";

			str += terrain->getHeight(camera->getAbsolutePosition().X,

					camera->getAbsolutePosition().Z);



			device->setWindowCaption(str.c_str());

			lastFPS = fps;

		}

	}



	device->drop();

	

	return 0;

}



/*

Now you know how to use terrain in Irrlicht.

**/