/** 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 <iostream>

using namespace irr;

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


class MyEventReceiver : public IEventReceiver
{
public:

	MyEventReceiver(scene::ISceneNode* terrain)
	{
		// store pointer to terrain so we can change its drawing mode
		Terrain = terrain;
	}

	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;
			}
		}

		return false;
	}

private:
	scene::ISceneNode* Terrain;
};


/*
The start of the main function starts like in most other example. We ask the user
for the desired renderer and start it up.
*/
int main()
{
	// let user select driver type

	video::E_DRIVER_TYPE driverType = video::EDT_DIRECT3D9;

	printf("Please select the driver you want for this example:\n"\
		" (a) Direct3D 9.0c\n (b) Direct3D 8.1\n (c) OpenGL 1.5\n"\
		" (d) Software Renderer\n (e) Burning's Software Renderer\n"\
		" (f) NullDevice\n (otherKey) exit\n\n");

	char i;
	std::cin >> i;

	switch(i)
	{
		case 'a': driverType = video::EDT_DIRECT3D9;break;
		case 'b': driverType = video::EDT_DIRECT3D8;break;
		case 'c': driverType = video::EDT_OPENGL;   break;
		case 'd': driverType = video::EDT_SOFTWARE; break;
		case 'e': driverType = video::EDT_BURNINGSVIDEO;break;
		case 'f': driverType = video::EDT_NULL;     break;
		default: return 1;
	}	

	// create device

	IrrlichtDevice* device = createDevice(driverType,
			core::dimension2d<s32>(640, 480));

	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 irrlicht logo
	env->addImage(driver->getTexture("../../media/irrlichtlogo2.png"),
		core::position2d<s32>(10,10));

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

	// add some help text
	gui::IGUIStaticText* text = env->addStaticText(
		L"Press 'W' to change wireframe mode\nPress 'D' to toggle detail map",
		core::rect<s32>(10,440,250,475), true, true, 0, -1, true);

	// add camera
	scene::ICameraSceneNode* camera =
		smgr->addCameraSceneNodeFPS(0,100.0f,1200.f);

	camera->setPosition(core::vector3df(1900*2,255*2,3700*2));
	camera->setTarget(core::vector3df(2397*2,343*2,2700*2));
	camera->setFarValue(12000.0f);

	// 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
		);

	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();

	/*
	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.
	*/

	// create event receiver
	MyEventReceiver receiver(terrain);
	device->setEventReceiver(&receiver);

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

	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"));

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


	/*
	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.
**/
