/*
-----------------------------------------------------------------------------
This source file is part of OGRE
    (Object-oriented Graphics Rendering Engine)
For the latest info, see http://www.ogre3d.org/

Copyright (c) 2000-2009 Torus Knot Software Ltd
Also see acknowledgements in Readme.html

You may use this sample code for anything you like, it is not covered by the
same license as the rest of the engine.
-----------------------------------------------------------------------------
*/
/* Static water simulation by eru
 * Started 29.05.2003, 20:54:37
 */

#include "SdkSample.h"
#include "SamplePlugin.h"

#include "OgreBillboardParticleRenderer.h"
#include "WaterMesh.h"

#include <iostream>
using namespace Ogre;
using namespace OgreBites;


// Mesh stuff
#define MESH_NAME "WaterMesh"
#define ENTITY_NAME "WaterEntity"
#define MATERIAL_PREFIX "Examples/Water"
#define MATERIAL_NAME "Examples/Water0"
#define COMPLEXITY 64 		// watch out - number of polys is 2*ACCURACY*ACCURACY !
#define PLANE_SIZE 3000.0f
#define CIRCLES_MATERIAL "Examples/Water/Circles"

/* Some global variables */
SceneNode *headNode ;
Overlay* waterOverlay ;
ParticleSystem *particleSystem ;
ParticleEmitter *particleEmitter ;
SceneManager *sceneMgr ;

void prepareCircleMaterial()
{
	char *bmap = new char[256 * 256 * 4] ;
	memset(bmap, 127, 256 * 256 * 4);
	for(int b=0;b<16;b++) {
		int x0 = b % 4 ;
		int y0 = b >> 2 ;
		Real radius = 4.0f + 1.4 * (float) b ;
		for(int x=0;x<64;x++) {
			for(int y=0;y<64;y++) {
				Real dist = Math::Sqrt((x-32)*(x-32)+(y-32)*(y-32)); // 0..ca.45
				dist = fabs(dist -radius -2) / 2.0f ;
				dist = dist * 255.0f;
				if (dist>255)
					dist=255 ;
				int colour = 255-(int)dist ;
				colour = (int)( ((Real)(15-b))/15.0f * (Real) colour );

				bmap[4*(256*(y+64*y0)+x+64*x0)+0]=colour ;
				bmap[4*(256*(y+64*y0)+x+64*x0)+1]=colour ;
				bmap[4*(256*(y+64*y0)+x+64*x0)+2]=colour ;
				bmap[4*(256*(y+64*y0)+x+64*x0)+3]=colour ;
			}
		}
	}

	DataStreamPtr imgstream(new MemoryDataStream(bmap, 256 * 256 * 4));
	//~ Image img;
	//~ img.loadRawData( imgstream, 256, 256, PF_A8R8G8B8 );
	//~ TextureManager::getSingleton().loadImage( CIRCLES_MATERIAL , img );
	TextureManager::getSingleton().loadRawData(CIRCLES_MATERIAL,
        ResourceGroupManager::DEFAULT_RESOURCE_GROUP_NAME,
		imgstream, 256, 256, PF_A8R8G8B8);
	MaterialPtr material =
		MaterialManager::getSingleton().create( CIRCLES_MATERIAL,
        ResourceGroupManager::DEFAULT_RESOURCE_GROUP_NAME);
	TextureUnitState *texLayer = material->getTechnique(0)->getPass(0)->createTextureUnitState( CIRCLES_MATERIAL );
	texLayer->setTextureAddressingMode( TextureUnitState::TAM_CLAMP );
	material->setSceneBlending( SBT_ADD );
	material->setDepthWriteEnabled( false ) ;
    material->load();
    // finished with bmap so release the memory
    delete [] bmap;
}


/* =========================================================================*/
/*               WaterCircle class                                          */
/* =========================================================================*/
#define CIRCLE_SIZE 500.0
#define CIRCLE_TIME 0.5f
class WaterCircle
{
private:
	String name ;
	SceneNode *node ;
	MeshPtr mesh ;
	SubMesh *subMesh ;
	Entity *entity ;
	Real tm ;
	static bool first ;
	// some buffers shared by all circles
	static HardwareVertexBufferSharedPtr posnormVertexBuffer ;
	static HardwareIndexBufferSharedPtr indexBuffer ; // indices for 2 faces
	static HardwareVertexBufferSharedPtr *texcoordsVertexBuffers ;

	float *texBufData;
	void _prepareMesh()
	{
		int i,lvl ;

		mesh = MeshManager::getSingleton().createManual(name,
            ResourceGroupManager::DEFAULT_RESOURCE_GROUP_NAME) ;
		subMesh = mesh->createSubMesh();
		subMesh->useSharedVertices=false;

		int numVertices = 4 ;

		if (first) { // first Circle, create some static common data
			first = false ;

			// static buffer for position and normals
			posnormVertexBuffer =
				HardwareBufferManager::getSingleton().createVertexBuffer(
					6*sizeof(float), // size of one vertex data
					4, // number of vertices
					HardwareBuffer::HBU_STATIC_WRITE_ONLY, // usage
					false); // no shadow buffer
			float *posnormBufData = (float*) posnormVertexBuffer->
				lock(HardwareBuffer::HBL_DISCARD);
			for(i=0;i<numVertices;i++) {
				posnormBufData[6*i+0]=((Real)(i%2)-0.5f)*CIRCLE_SIZE; // pos X
				posnormBufData[6*i+1]=0; // pos Y
				posnormBufData[6*i+2]=((Real)(i/2)-0.5f)*CIRCLE_SIZE; // pos Z
				posnormBufData[6*i+3]=0 ; // normal X
				posnormBufData[6*i+4]=1 ; // normal Y
				posnormBufData[6*i+5]=0 ; // normal Z
			}
			posnormVertexBuffer->unlock();

			// static buffers for 16 sets of texture coordinates
			texcoordsVertexBuffers = new HardwareVertexBufferSharedPtr[16];
			for(lvl=0;lvl<16;lvl++) {
				texcoordsVertexBuffers[lvl] =
					HardwareBufferManager::getSingleton().createVertexBuffer(
						2*sizeof(float), // size of one vertex data
						numVertices, // number of vertices
						HardwareBuffer::HBU_STATIC_WRITE_ONLY, // usage
						false); // no shadow buffer
				float *texcoordsBufData = (float*) texcoordsVertexBuffers[lvl]->
					lock(HardwareBuffer::HBL_DISCARD);
				float x0 = (Real)(lvl % 4) * 0.25 ;
				float y0 = (Real)(lvl / 4) * 0.25 ;
				y0 = 0.75-y0 ; // upside down
				for(i=0;i<4;i++) {
					texcoordsBufData[i*2 + 0]=
						x0 + 0.25 * (Real)(i%2) ;
					texcoordsBufData[i*2 + 1]=
						y0 + 0.25 * (Real)(i/2) ;
				}
				texcoordsVertexBuffers[lvl]->unlock();
			}

			// Index buffer for 2 faces
			unsigned short faces[6] = {2,1,0,  2,3,1};
			indexBuffer =
				HardwareBufferManager::getSingleton().createIndexBuffer(
					HardwareIndexBuffer::IT_16BIT,
					6,
					HardwareBuffer::HBU_STATIC_WRITE_ONLY);
			indexBuffer->writeData(0,
				indexBuffer->getSizeInBytes(),
				faces,
				true); // true?
		}

		// Initialize vertex data
		subMesh->vertexData = new VertexData();
		subMesh->vertexData->vertexStart = 0;
		subMesh->vertexData->vertexCount = 4;
		// first, set vertex buffer bindings
		VertexBufferBinding *vbind = subMesh->vertexData->vertexBufferBinding ;
		vbind->setBinding(0, posnormVertexBuffer);
		vbind->setBinding(1, texcoordsVertexBuffers[0]);
		// now, set vertex buffer declaration
		VertexDeclaration *vdecl = subMesh->vertexData->vertexDeclaration ;
		vdecl->addElement(0, 0, VET_FLOAT3, VES_POSITION);
		vdecl->addElement(0, 3*sizeof(float), VET_FLOAT3, VES_NORMAL);
		vdecl->addElement(1, 0, VET_FLOAT2, VES_TEXTURE_COORDINATES);

		// Initialize index data
		subMesh->indexData->indexBuffer = indexBuffer;
		subMesh->indexData->indexStart = 0;
		subMesh->indexData->indexCount = 6;

		// set mesh bounds
		AxisAlignedBox circleBounds(-CIRCLE_SIZE/2.0f, 0, -CIRCLE_SIZE/2.0f,
			CIRCLE_SIZE/2.0f, 0, CIRCLE_SIZE/2.0f);
		mesh->_setBounds(circleBounds);
        mesh->load();
        mesh->touch();
	}
public:
	int lvl ;
	void setTextureLevel()
	{
		subMesh->vertexData->vertexBufferBinding->setBinding(1, texcoordsVertexBuffers[lvl]);
	}
	WaterCircle(const String& name, Real x, Real y)
	{
		this->name = name ;
		_prepareMesh();
		node = static_cast<SceneNode*> (sceneMgr->getRootSceneNode()->createChild(name));
		node->translate(x*(PLANE_SIZE/COMPLEXITY), 10, y*(PLANE_SIZE/COMPLEXITY));
		entity = sceneMgr->createEntity(name, name);
		entity->setMaterialName(CIRCLES_MATERIAL);
		node->attachObject(entity);
		tm = 0 ;
		lvl = 0 ;
		setTextureLevel();
	}
	~WaterCircle()
	{
		MeshManager::getSingleton().remove(mesh->getHandle());
		sceneMgr->destroyEntity(entity->getName());
		static_cast<SceneNode*> (sceneMgr->getRootSceneNode())->removeChild(node->getName());
	}
	void animate(Real timeSinceLastFrame)
	{
		int lastlvl = lvl ;
		tm += timeSinceLastFrame ;
		lvl = (int) ( (Real)(tm)/CIRCLE_TIME * 16 );
		if (lvl<16 && lvl!=lastlvl) {
			setTextureLevel();
		}
	}
	static void clearStaticBuffers()
	{
		posnormVertexBuffer = HardwareVertexBufferSharedPtr() ;
		indexBuffer = HardwareIndexBufferSharedPtr() ;
		for(int i=0;i<16;i++) {
			texcoordsVertexBuffers[i] = HardwareVertexBufferSharedPtr() ;
		}
		delete [] texcoordsVertexBuffers;
	}
} ;
bool WaterCircle::first = true ;
HardwareVertexBufferSharedPtr WaterCircle::posnormVertexBuffer =
	HardwareVertexBufferSharedPtr() ;
HardwareIndexBufferSharedPtr WaterCircle::indexBuffer =
	HardwareIndexBufferSharedPtr() ;
HardwareVertexBufferSharedPtr* WaterCircle::texcoordsVertexBuffers = 0 ;

class _OgreSampleClassExport Sample_Water : public SdkSample
{
public:
    Sample_Water(): waterMesh(0)
    {
		mInfo["Title"] = "Water";
		mInfo["Description"] = "A demo of a simple water effect.";
		mInfo["Thumbnail"] = "thumb_water.png";
		mInfo["Category"] = "Environment";
    }
    
protected:
	WaterMesh *waterMesh ;
	Entity *waterEntity ;
	AnimationState* mAnimState;

// Just override the mandatory create scene method
    void setupContent(void)
    {
		sceneMgr = mSceneMgr ;
        // Set ambient light
        mSceneMgr->setAmbientLight(ColourValue(0.75, 0.75, 0.75));

        // Create a light
        Light* l = mSceneMgr->createLight("MainLight");
        // Accept default settings: point light, white diffuse, just set position
        // NB I could attach the light to a SceneNode if I wanted it to move automatically with
        //  other objects, but I don't
        l->setPosition(200,300,100);

		// Create water mesh and entity
		waterMesh = new WaterMesh(MESH_NAME, PLANE_SIZE, COMPLEXITY);
		waterEntity = mSceneMgr->createEntity(ENTITY_NAME,
			MESH_NAME);
		//~ waterEntity->setMaterialName(MATERIAL_NAME);
		SceneNode *waterNode = mSceneMgr->getRootSceneNode()->createChildSceneNode();
		waterNode->attachObject(waterEntity);

        // Add a head, give it it's own node
        headNode = waterNode->createChildSceneNode();
        Entity *ent = mSceneMgr->createEntity("head", "ogrehead.mesh");
        headNode->attachObject(ent);

		// Make sure the camera track this node
        //~ mCamera->setAutoTracking(true, headNode);

		// Create the camera node, set its position & attach camera
        SceneNode* camNode = mSceneMgr->getRootSceneNode()->createChildSceneNode();
		camNode->translate(0, 500, PLANE_SIZE);
		camNode->yaw(Degree(-45));
        camNode->attachObject(mCamera);

		// Create light node
        SceneNode* lightNode = mSceneMgr->getRootSceneNode()->createChildSceneNode();
		lightNode->attachObject(l);

        // set up spline animation of light node
        Animation* anim = mSceneMgr->createAnimation("WaterLight", 20);
		NodeAnimationTrack *track ;
        TransformKeyFrame *key ;
		// create a random spline for light
		track = anim->createNodeTrack(0, lightNode);
		key = track->createNodeKeyFrame(0);
		for(int ff=1;ff<=19;ff++) {
			key = track->createNodeKeyFrame(ff);
			Vector3 lpos (
				rand()%(int)PLANE_SIZE , //- PLANE_SIZE/2,
				rand()%300+100,
				rand()%(int)PLANE_SIZE //- PLANE_SIZE/2
				);
			key->setTranslate(lpos);
		}
		key = track->createNodeKeyFrame(20);

        // Create a new animation state to track this
        mAnimState = mSceneMgr->createAnimationState("WaterLight");
        mAnimState->setEnabled(true);

        // Put in a bit of fog for the hell of it
        //mSceneMgr->setFog(FOG_EXP, ColourValue::White, 0.0002);

		// Let there be rain
        particleSystem = mSceneMgr->createParticleSystem("rain",
            "Examples/Water/Rain");
		particleEmitter = particleSystem->getEmitter(0);
        SceneNode* rNode = mSceneMgr->getRootSceneNode()->createChildSceneNode();
        rNode->translate(PLANE_SIZE/2.0f, 3000, PLANE_SIZE/2.0f);
        rNode->attachObject(particleSystem);
        // Fast-forward the rain so it looks more natural
        particleSystem->fastForward(20);
		// It can't be set in .particle file, and we need it ;)
		static_cast<BillboardParticleRenderer*>(particleSystem->getRenderer())->setBillboardOrigin(BBO_BOTTOM_CENTER);

		prepareCircleMaterial();

		setupControls();

		setDragLook(true);

		timeoutDelay = 0.0f;
	}

#define PANEL_WIDTH 200
	void setupControls()
	{
		mTrayMgr->createLabel(TL_TOPLEFT, "GeneralLabel", "General", PANEL_WIDTH);
		mTrayMgr->createCheckBox(TL_TOPLEFT, "FakeNormalsCB", "Fake normals", PANEL_WIDTH);
		mTrayMgr->createCheckBox(TL_TOPLEFT, "SkyboxCB", "Skybox", PANEL_WIDTH);
		mTrayMgr->createThickSlider(TL_TOPLEFT, "HeadDepthSlider", "Head Depth", PANEL_WIDTH, 80, 1, 3, 50)->setValue(2.0f);
		SelectMenu* waterMaterial = mTrayMgr->createThickSelectMenu(TL_TOPLEFT, "WaterMaterialMenu", "Water material", PANEL_WIDTH, 9);
		for (size_t i = 0; i < 9; i++)
		{
			waterMaterial->addItem(MATERIAL_PREFIX + StringConverter::toString(i));
		}
		waterMaterial->selectItem(8);
		mTrayMgr->createLabel(TL_TOPLEFT, "RainLabel", "Rain : [Space]", PANEL_WIDTH);
		
		mTrayMgr->createLabel(TL_TOPRIGHT, "AdvancedLabel", "Advanced", PANEL_WIDTH);
		mTrayMgr->createThickSlider(TL_TOPRIGHT, "RippleSpeedSlider", "Ripple Speed", PANEL_WIDTH, 80, 0, 2, 50)->setValue(0.3, false);
		mTrayMgr->createThickSlider(TL_TOPRIGHT, "DistanceSlider", "Distance", PANEL_WIDTH, 80, 0.1, 5.0, 50)->setValue(0.4, false);
		mTrayMgr->createThickSlider(TL_TOPRIGHT, "ViscositySlider", "Viscosity", PANEL_WIDTH, 80, 0, 1, 50)->setValue(0.05, false);
		mTrayMgr->createThickSlider(TL_TOPRIGHT, "FrameTimeSlider", "FrameTime", PANEL_WIDTH, 80, 0, 1, 61)->setValue(0.13, false);

		mTrayMgr->showCursor();
	}

	void cleanupContent()
	{
		// If when you finish the application is still raining there
 		// are water circles that are still being processed
 		unsigned int activeCircles = this->circles.size ();

 		// Kill the active water circles
 		for (unsigned int i = 0; i < activeCircles; i++)
 			delete (this->circles[i]);

		delete waterMesh;
		waterMesh = 0;
	}

    protected:
	Real timeoutDelay ;

#define RAIN_HEIGHT_RANDOM 5
#define RAIN_HEIGHT_CONSTANT 5


	typedef vector<WaterCircle*>::type WaterCircles ;
	WaterCircles circles ;

	void processCircles(Real timeSinceLastFrame)
	{
		for(unsigned int i=0;i<circles.size();i++) {
			circles[i]->animate(timeSinceLastFrame);
		}
		bool found ;
		do {
			found = false ;
			for(WaterCircles::iterator it = circles.begin() ;
					it != circles.end();
					++it) {
				if ((*it)->lvl>=16) {
					delete (*it);
					circles.erase(it);
					found = true ;
					break ;
				}
			}
		} while (found) ;
	}

	void processParticles()
	{
		static int pindex = 0 ;
		ParticleIterator pit = particleSystem->_getIterator() ;
		while(!pit.end()) {
			Particle *particle = pit.getNext();
			Vector3 ppos = particle->position;
			if (ppos.y<=0 && particle->timeToLive>0) { // hits the water!
				// delete particle
				particle->timeToLive = 0.0f;
				// push the water
				float x = ppos.x / PLANE_SIZE * COMPLEXITY ;
				float y = ppos.z / PLANE_SIZE * COMPLEXITY ;
				float h = rand() % RAIN_HEIGHT_RANDOM + RAIN_HEIGHT_CONSTANT ;
				if (x<1) x=1 ;
				if (x>COMPLEXITY-1) x=COMPLEXITY-1;
				if (y<1) y=1 ;
				if (y>COMPLEXITY-1) y=COMPLEXITY-1;
				waterMesh->push(x,y,-h) ;
				WaterCircle *circle = new WaterCircle(
					"Circle#"+StringConverter::toString(pindex++),
					x, y);
				circles.push_back(circle);
			}
		}
	}

	void sliderMoved(Slider* slider)
	{
		if (slider->getName() == "HeadDepthSlider")
		{
			headDepth = slider->getValue();
		}
		else if (slider->getName() == "RippleSpeedSlider")
		{
			waterMesh->PARAM_C = slider->getValue();
		}
		else if (slider->getName() == "DistanceSlider")
		{
			waterMesh->PARAM_D = slider->getValue();
		}
		else if (slider->getName() == "ViscositySlider")
		{
			waterMesh->PARAM_U = slider->getValue();
		}
		else if (slider->getName() == "FrameTimeSlider")
		{
			waterMesh->PARAM_T = slider->getValue();
		}
	}

	void checkBoxToggled(CheckBox* checkBox)
	{
		if (checkBox->getName() == "FakeNormalsCB")
		{
			waterMesh->useFakeNormals = checkBox->isChecked();
		}
		else if (checkBox->getName() == "SkyboxCB")
		{
			sceneMgr->setSkyBox(checkBox->isChecked(), "Examples/SceneSkyBox2");
		}
	}

	void itemSelected(SelectMenu* menu)
	{
		//Only one menu in this demo
		const String& materialName = menu->getSelectedItem();
		MaterialPtr material = MaterialManager::getSingleton().getByName(materialName);
		if (material.isNull())
        {
			OGRE_EXCEPT(Exception::ERR_INTERNAL_ERROR,
				"Material "+materialName+"doesn't exist!",
				"WaterListener::updateMaterial");
		}
		waterEntity->setMaterialName(materialName);
	}

	/** Head animation */
	Real headDepth ;
	void animateHead(Real timeSinceLastFrame)
	{
		// sine track? :)
		static double sines[4] = {0,100,200,300};
		static const double adds[4] = {0.3,-1.6,1.1,0.5};
		static Vector3 oldPos = Vector3::UNIT_Z;
		for(int i=0;i<4;i++) {
			sines[i]+=adds[i]*timeSinceLastFrame;
		}
		Real tx = ((sin(sines[0]) + sin(sines[1])) / 4 + 0.5 ) * (float)(COMPLEXITY-2) + 1 ;
		Real ty = ((sin(sines[2]) + sin(sines[3])) / 4 + 0.5 ) * (float)(COMPLEXITY-2) + 1 ;
		waterMesh->push(tx,ty, -headDepth);
		Real step = PLANE_SIZE / COMPLEXITY ;
		headNode->resetToInitialState();
		headNode->scale(3,3,3);
		Vector3 newPos = Vector3(step*tx, headDepth, step*ty);
		Vector3 diffPos = newPos - oldPos ;
		Quaternion headRotation = Vector3::UNIT_Z.getRotationTo(diffPos);
		oldPos = newPos ;
		headNode->translate(newPos);
		headNode->rotate(headRotation);
	}

public:
    

    bool frameRenderingQueued(const FrameEvent& evt)
    {
		if( SdkSample::frameRenderingQueued(evt) == false )
		{
			// check if we are exiting, if so, clear static HardwareBuffers to avoid segfault
			WaterCircle::clearStaticBuffers();
			return false;
		}

        mAnimState->addTime(evt.timeSinceLastFrame);

		// rain
		processCircles(evt.timeSinceLastFrame);
#if OGRE_PLATFORM != OGRE_PLATFORM_IPHONE
		if (mKeyboard->isKeyDown(OIS::KC_SPACE)) {
			particleEmitter->setEmissionRate(20.0f);
		} else {
			particleEmitter->setEmissionRate(0.0f);
		}
#endif
		processParticles();


		timeoutDelay-=evt.timeSinceLastFrame ;
		if (timeoutDelay<=0)
			timeoutDelay = 0;

		animateHead(evt.timeSinceLastFrame);

		waterMesh->updateMesh(evt.timeSinceLastFrame);

		return true;
    }
};

#ifndef OGRE_STATIC_LIB

SamplePlugin* sp;
Sample* s;

extern "C" _OgreSampleExport void dllStartPlugin()
{
	s = new Sample_Water;
	sp = OGRE_NEW SamplePlugin(s->getInfo()["Title"] + " Sample");
	sp->addSample(s);
	Root::getSingleton().installPlugin(sp);
}

extern "C" _OgreSampleExport void dllStopPlugin()
{
	Root::getSingleton().uninstallPlugin(sp); 
	OGRE_DELETE sp;
	delete s;
}
#endif
