/*
Basic diffusion and FRAP simulation
 Jonathan Ward and Francois Nedelec, Copyright EMBL Nov. 2007-2009

 
To compile on the mac:
 g++ main.cc -framework GLUT -framework OpenGL -o frap

To compile on Windows using Cygwin:
 g++ main.cc -lopengl32 -lglut32 -o frap
 
To compile on Linux:
 g++ main.cc -lglut -lopengl -o frap
*/

#include "params.h"
#ifdef __APPLE__
#  include <GLUT/glut.h>
#else
#  include "GL/glut.h"
#endif
#include <list>
#include <vector>
#include <iostream>
#include <math.h>

#include "../cmath3d/TriangleMesh.h"
#include "../cmath3d_v/TriangleMesh_v.h"


//link to the global params
extern ParamsClass params;
extern ActiveMesh mesh;

///whether the simulation is paused (=1) or not (=0)
int pauseSimulation=1;
///how big chunks of steps should be taken between drawing
int stepGranularity=1;

///OpenGL window size -> to recalculate from windows coords to scene coords
int windowSizeX=0, windowSizeY=0;

float uhel_x = 0.0, uhel_y = 0.0;
float zoom = 1.0;

bool MouseActive = false;
int last_x = 0, last_y = 0;

bool showAxes=true;
bool showFrame=false;
bool showBox=true;

bool showWholeMesh=true;
bool showVertexSurface=false;
bool showQuadricSurface=false;
bool showTEST=false;


///manage \e count steps of the simulation and then print and draw
void step(int count)
{
	while ((params.currTime < params.stopTime) && (count > 0))
	{
		//do some job

		params.currTime += params.incrTime;
		--count;
	}
	
	if (params.currTime >= params.stopTime)
	{
		std::cout << "END OF THE SIMULATION HAS BEEN REACHED\n";
		pauseSimulation=1;
	}

	std::cout << "\nnow at time: " << params.currTime << "\n";

	//ask GLUT to call the display function
	glutPostRedisplay();
}


///draws a flat frame around the playground
void displayFrame(void)
{
    glColor3f(params.sceneBorderColour.r,
	 			  params.sceneBorderColour.g,
	 			  params.sceneBorderColour.b);
    glLineWidth(1);
    glBegin(GL_LINE_LOOP);
    glVertex3f( params.sceneOffset.x , params.sceneOffset.y , params.sceneCentre.z );
    glVertex3f( params.sceneOffset.x + params.sceneSize.x , params.sceneOffset.y , params.sceneCentre.z );
    glVertex3f( params.sceneOffset.x + params.sceneSize.x , params.sceneOffset.y + params.sceneSize.y , params.sceneCentre.z );
    glVertex3f( params.sceneOffset.x , params.sceneOffset.y + params.sceneSize.y , params.sceneCentre.z );
    glEnd();
}

///draws a frame box around the playground
void displayBox(void)
{
    glColor3f(params.sceneBorderColour.r,
	 			  params.sceneBorderColour.g,
	 			  params.sceneBorderColour.b);
    glLineWidth(1);
	 //front square/plane
    glBegin(GL_LINE_LOOP);
    glVertex3f( params.sceneOffset.x                      , params.sceneOffset.y                      , params.sceneOffset.z );
    glVertex3f( params.sceneOffset.x + params.sceneSize.x , params.sceneOffset.y                      , params.sceneOffset.z );
    glVertex3f( params.sceneOffset.x + params.sceneSize.x , params.sceneOffset.y + params.sceneSize.y , params.sceneOffset.z );
    glVertex3f( params.sceneOffset.x                      , params.sceneOffset.y + params.sceneSize.y , params.sceneOffset.z );
    glEnd();

	 //rear square/plane
    glBegin(GL_LINE_LOOP);
    glVertex3f( params.sceneOffset.x                      , params.sceneOffset.y                      , params.sceneOffset.z + params.sceneSize.z );
    glVertex3f( params.sceneOffset.x + params.sceneSize.x , params.sceneOffset.y                      , params.sceneOffset.z + params.sceneSize.z );
    glVertex3f( params.sceneOffset.x + params.sceneSize.x , params.sceneOffset.y + params.sceneSize.y , params.sceneOffset.z + params.sceneSize.z );
    glVertex3f( params.sceneOffset.x                      , params.sceneOffset.y + params.sceneSize.y , params.sceneOffset.z + params.sceneSize.z );
    glEnd();

	 //sideways "connectors"
	 glBegin(GL_LINES);
    glVertex3f( params.sceneOffset.x                      , params.sceneOffset.y                      , params.sceneOffset.z );
    glVertex3f( params.sceneOffset.x                      , params.sceneOffset.y                      , params.sceneOffset.z + params.sceneSize.z );

    glVertex3f( params.sceneOffset.x + params.sceneSize.x , params.sceneOffset.y                      , params.sceneOffset.z );
    glVertex3f( params.sceneOffset.x + params.sceneSize.x , params.sceneOffset.y                      , params.sceneOffset.z + params.sceneSize.z );

    glVertex3f( params.sceneOffset.x + params.sceneSize.x , params.sceneOffset.y + params.sceneSize.y , params.sceneOffset.z );
    glVertex3f( params.sceneOffset.x + params.sceneSize.x , params.sceneOffset.y + params.sceneSize.y , params.sceneOffset.z + params.sceneSize.z );

    glVertex3f( params.sceneOffset.x                      , params.sceneOffset.y + params.sceneSize.y , params.sceneOffset.z );
    glVertex3f( params.sceneOffset.x                      , params.sceneOffset.y + params.sceneSize.y , params.sceneOffset.z + params.sceneSize.z );
    glEnd();
}

void displayAxes(void)
{
	glLineWidth(2);
	glBegin(GL_LINES);
	glColor3f(1.0,0.0,0.0); //red   -- x axis
	glVertex3f(params.sceneCentre.x,params.sceneCentre.y,params.sceneCentre.z);
	glVertex3f(params.sceneCentre.x+params.sceneSize.x/4.f,params.sceneCentre.y,params.sceneCentre.z);

	glColor3f(0.0,1.0,0.0); //green -- y axis
	glVertex3f(params.sceneCentre.x,params.sceneCentre.y,params.sceneCentre.z);
	glVertex3f(params.sceneCentre.x,params.sceneCentre.y+params.sceneSize.y/4.f,params.sceneCentre.z);

	glColor3f(0.0,0.0,1.0); //blue  -- z axis
	glVertex3f(params.sceneCentre.x,params.sceneCentre.y,params.sceneCentre.z);
	glVertex3f(params.sceneCentre.x,params.sceneCentre.y,params.sceneCentre.z+params.sceneSize.z/4.f);
	glEnd();
	glLineWidth(1);
}


int VertexID=10;
int vertexLevels=5;
void ActiveMesh::displayVertexAndNeigs(void)
{
	//determine some reasonable number of nearest neighbors
	std::vector< std::vector<size_t> > neigsLeveled;
	ulm::getVertexNeighbours(*this,VertexID,vertexLevels,neigsLeveled);

	//make it flat...
	std::vector<size_t> neigs;
	for (unsigned int l=0; l < neigsLeveled.size(); ++l)
		for (unsigned int i=0; i < neigsLeveled[l].size(); ++i)
			neigs.push_back(neigsLeveled[l][i]);
	neigsLeveled.clear();

	/*
	std::vector<size_t> neigs;
	ulm::getVertexImmediateNeighbours(*this,VertexID,neigs);
	*/

	glPointSize(3.0f);
	glBegin(GL_POINTS);

	// centre vertex:
	glColor3f(0.0f,0.0f,1.0f);
	glVertex3f(Pos[VertexID].x,Pos[VertexID].y,Pos[VertexID].z);

	// neigs:
	glColor3f(1.0f,0.0f,0.0f);
	for (unsigned int i=1; i < neigs.size(); ++i)
		glVertex3f(Pos[neigs[i]].x,Pos[neigs[i]].y,Pos[neigs[i]].z);

	glEnd();
}

void ActiveMesh::displayTEST(void)
{
	//get surface params
	float surf_coeff[10];
	//CalcQuadricSurface_Taubin(VertexID,surf_coeff);
	CalcQuadricSurface_sphere(5.0f,params.sceneCentre,surf_coeff);
	std::cout << "\nsurface: " << surf_coeff[0] << " + "
	          << surf_coeff[1] << "*x + "
	          << surf_coeff[2] << "*y + "
	          << surf_coeff[3] << "*z + "
	          << surf_coeff[4] << "*xy + "
	          << surf_coeff[5] << "*xz + "
	          << surf_coeff[6] << "*yz + "
	          << surf_coeff[7] << "*x*x + "
	          << surf_coeff[8] << "*y*y + "
	          << surf_coeff[9] << "*z*z = 0\n";

	glPointSize(2.0f);
	glBegin(GL_POINTS);
	glColor3f(0.0f,1.0f,0.0f);

		//determine triangle vertices
		const Vector3FC& v1=Pos[VertexID];
		std::cout << "v1: (" << v1.x << "," << v1.y << "," << v1.z << ")\n";

			Vector3F point=v1;

			//backup...
			Vector3F origPoint(point);

			//adapt the point
			std::cout << "dist=" <<
			GetClosestPointOnQuadricSurface(point,surf_coeff);

			//display the point
			glColor3f(0.0f,1.0f,0.0f);
			//glVertex3f(point.x,point.y,point.z);

			float tmp1,tmp2;
			if (GetPointOnQuadricSurface(v1.x,v1.y,tmp1,tmp2,surf_coeff))
			{
				glVertex3f(v1.x,v1.y,tmp1);
				glVertex3f(v1.x,v1.y,tmp2);
			}
			if (GetPointOnQuadricSurface(v1.x,v1.z,tmp1,tmp2,surf_coeff))
			{
				glVertex3f(v1.x,tmp1,v1.z);
				glVertex3f(v1.x,tmp2,v1.z);
			}
			if (GetPointOnQuadricSurface(v1.y,v1.z,tmp1,tmp2,surf_coeff))
			{
				glVertex3f(tmp1,v1.y,v1.z);
				glVertex3f(tmp2,v1.y,v1.z);
			}
			/*
			std::cout << "  (" << origPoint.x << "," << origPoint.y << "," << origPoint.z
			          << ") -> ("
			          << point.x << "," << point.y << "," << point.z << ")\n";
			*/

			glColor3f(0.0f,1.0f,1.0f);
			//glVertex3f(origPoint.x,origPoint.y,origPoint.z);

	glEnd();
}

void ActiveMesh::displayQuadricSurface(void)
{

	//zkusit nad dalsimi krivkami, paraboloid?
	//pripadne udelat jinak dopocitavani na povrch..
	//bo to nyni dava docela velke vzdalenosti pro vypocitany povrch


	//get surface params
	float surf_coeff[10];
	//CalcQuadricSurface_Taubin(VertexID,surf_coeff);
	CalcQuadricSurface_sphere(5.0f,params.sceneCentre,surf_coeff);
	std::cout << "\nsurface: " << surf_coeff[0] << " + "
	          << surf_coeff[1] << "*x + "
	          << surf_coeff[2] << "*y + "
	          << surf_coeff[3] << "*z + "
	          << surf_coeff[4] << "*xy + "
	          << surf_coeff[5] << "*xz + "
	          << surf_coeff[6] << "*yz + "
	          << surf_coeff[7] << "*x*x + "
	          << surf_coeff[8] << "*y*y + "
	          << surf_coeff[9] << "*z*z = 0\n";

	glPointSize(2.0f);
	glBegin(GL_POINTS);
	glColor3f(0.0f,1.0f,0.0f);

	//do the rendering, i.e., take incident triangles
	//and sample points from them and project
	//these points on the obtained surface

	//list of neigs triangle IDs
	std::vector<size_t> neigsT;
	ulm::getVertexIncidentTriangles(*this,VertexID,neigsT);

	//FOR CYCLE BEGIN
	//over all triangles
	//for (unsigned int t=0; t < neigsT.size(); ++t)
	for (unsigned int t=0; t < 1; ++t)
	{
		//determine triangle vertices
		const Vector3FC& v1=Pos[ID[3*neigsT[t] +0]];
		const Vector3FC& v2=Pos[ID[3*neigsT[t] +1]];
		const Vector3FC& v3=Pos[ID[3*neigsT[t] +2]];
		std::cout << "v1: (" << v1.x << "," << v1.y << "," << v1.z << ")\n";
		std::cout << "v2: (" << v2.x << "," << v2.y << "," << v2.z << ")\n";
		std::cout << "v3: (" << v3.x << "," << v3.y << "," << v3.z << ")\n";

		//sweep (coarsely!) across current triangle
		for (float c=0.1f; c <= 0.9f; c += 0.1f)
		for (float b=0.1f; b <= (0.9f-c); b += 0.1f)
		{
			float a=1.0f -b -c;

			Vector3F point=a*v1;
			point+=b*v2;
			point+=c*v3;

			//backup...
			Vector3F origPoint(point);

			//adapt the point
			std::cout << "dist=" <<
			GetClosestPointOnQuadricSurface(point,surf_coeff);

			//display the point
			glColor3f(0.0f,1.0f,0.0f);
			glVertex3f(point.x,point.y,point.z);
			std::cout << "  (" << origPoint.x << "," << origPoint.y << "," << origPoint.z
			          << ") -> ("
			          << point.x << "," << point.y << "," << point.z << ")\n";

			glColor3f(0.0f,1.0f,1.0f);
			glVertex3f(origPoint.x,origPoint.y,origPoint.z);
		}
	}
	//FOR CYCLE END

	glEnd();
}

void ActiveMesh::displayMesh(void)
{
	glColor3f(0.6f,0.6f,0.6f);

	long unsigned int* id=ID.data();
	for (unsigned int i=0; i < ID.size(); i+=3)
	{
		//glBegin(GL_TRIANGLES);
		glBegin(GL_LINE_LOOP);
		glNormal3f(norm[i/3].x,norm[i/3].y,norm[i/3].z);
		glVertex3f(Pos[*id].x,Pos[*id].y,Pos[*id].z); ++id;
		glVertex3f(Pos[*id].x,Pos[*id].y,Pos[*id].z); ++id;
		glVertex3f(Pos[*id].x,Pos[*id].y,Pos[*id].z); ++id;
		glEnd();
	}
}


void display(void)
{
	glClear(GL_COLOR_BUFFER_BIT);
	glLoadIdentity();
	glTranslatef(params.sceneCentre.x,params.sceneCentre.y,params.sceneCentre.z);
	glScalef(zoom,zoom,zoom);
	Vector3d<float> eye=params.sceneCentre;
	eye.x+=params.sceneSize.z*sinf(uhel_x)*cosf(uhel_y);
	eye.y+=params.sceneSize.z*sinf(uhel_y);
	eye.z+=params.sceneSize.z*cosf(uhel_x)*cosf(uhel_y);
	gluLookAt(eye.x,eye.y,eye.z, //eye
				 params.sceneCentre.x,params.sceneCentre.y,params.sceneCentre.z, //center
	          //0.0, cosf(-uhel_y), sinf(-uhel_y)); // up
	          0.0, 1.0, 0.0); // up

	glEnable(GL_FOG);
	if (showBox) displayBox();
	if (showFrame) displayFrame();
	if (showAxes) displayAxes();
	glDisable(GL_FOG);

	if (showWholeMesh) mesh.displayMesh();
	if (showVertexSurface) mesh.displayVertexAndNeigs();
	if (showQuadricSurface) mesh.displayQuadricSurface();
	if (showTEST) mesh.displayTEST();

	glFlush();
	glutSwapBuffers();
}


// called automatically after a certain amount of time
void timer(int)
{
	 //do simulation and then draw
    step(stepGranularity);

    //ask GLUT to call 'timer' again in 'delay' milli-seconds:
	 //in the meantime, you can inspect the drawing :-)
    if (!pauseSimulation) glutTimerFunc(500, timer, 0);
}

void GetSceneViewSize(const int w,const int h,
							float& xVisF, float& xVisT,
							float& yVisF, float& yVisT)
{
	 //what is the desired size of the scene
	 const float xBound=params.sceneSize.x
	 				+ 2.f*params.sceneOuterBorder.x;
	 const float yBound=params.sceneSize.y
	 				+ 2.f*params.sceneOuterBorder.y;

	 xVisF = params.sceneOffset.x - params.sceneOuterBorder.x;
	 yVisF = params.sceneOffset.y - params.sceneOuterBorder.y;
	 xVisT = xBound + xVisF;
	 yVisT = yBound + yVisF;

    if ( (float)w * yBound < (float)h * xBound )		//equals to  w/h < x/y
	 {
	 	//window is closer to the rectangle than the scene shape
		  yVisF *= ((float)h / float(w)) * (xBound/yBound);
        yVisT *= ((float)h / float(w)) * (xBound/yBound);
	 }
	 else
	 {
		  xVisF *= ((float)w / float(h)) * (yBound/xBound);
        xVisT *= ((float)w / float(h)) * (yBound/xBound);
	 }
}


void printKeysHelp(void)
{
	std::cout << "\nKeys:\n";
	std::cout << "ESC or 'q': quit        ENTER: enters empty line on a console\n";
	std::cout << "' ','n','z': simulation goes/stop at various steps\n";
	std::cout << "'r': resets the view\n";
	std::cout << "'o','O': zoom in,out\n";
	std::cout << "'h': displays this help\n";
	std::cout << "'d': displays enabled features,displays status\n";
	std::cout << "'m': toggle display of the mesh\n";
	std::cout << "'v': toggle display of the vertex supporting region\n";
	std::cout << "'V': chooses another vertex\n";
	std::cout << "'s': toggle display of the fitted quadratic surface \n";
	std::cout << "'t': toggle display of the test/debug function\n";
	std::cout << "'a': toggle display of the R,G,B <-> x,y,z axes \n";
	std::cout << "'f': toggle display of the frame/plane az z=0\n";
	std::cout << "'b': toggle display of the bounding box\n";
	std::cout << "'x','X': controls for some testing\n";
	std::cout << "'i': not used\n";
}


void printDispayedFeauters(void)
{
	if (pauseSimulation) std::cout << "\nsimulation is now paused\n";
	else std::cout << "\nsimulation is now in progress\n";
	std::cout << "simulation time progress " << params.currTime/params.stopTime*100.f
		<< "%, delta time is " << params.incrTime << " minutes\n";

	std::cout << "viewing: x_ang=" << uhel_x << ", y_ang=" << uhel_y
	          << ", zoom=" << zoom << "\n";

	std::cout << "Currently displayed features:\n";
}


// called when a key is pressed
void keyboard(unsigned char key, int mx, int my)
{
	//required for calculating the mouse position within the scene coords
	float xVisF, yVisF;
	float xVisT, yVisT;
	float sx,sy;

    switch (key) {
        case 27:   //this corresponds to 'escape'
        case 'q':  //quit
            exit(EXIT_SUCCESS);
            break;
			case 13: //Enter key -- just empty lines
				std::cout << std::endl;
				break;

		  //control execution of the simulation
        case ' ':  //pause/unpause, refresh every 10 cycles
				if (params.currTime < params.stopTime) pauseSimulation^=1;
				if (!pauseSimulation)
				{
					stepGranularity=1; //= 1 min
					timer(0);
				}
            break;
        case 'z':  //pause/unpause, refresh every 600 cycles
				if (params.currTime < params.stopTime) pauseSimulation^=1;
				if (!pauseSimulation)
				{
					stepGranularity=100; //= 10 min
					timer(0);
				}
            break;
        case 'n':  //pause, advance by one frame
				pauseSimulation=1;
				step(1);
            break;

		  //view params
        case 'r':  //set scale 1:1
				uhel_x = 0.0;
				uhel_y = 0.0;
				zoom = 1.0;
				glutReshapeWindow(int(params.imgSizeX),int(params.imgSizeY));
				glutPostRedisplay();
            break;
			case 'o':
				zoom -= 0.2f;
				if (zoom < 0.2f) zoom=0.2f;
				glutPostRedisplay();
				break;
			case 'O':
				zoom += 0.2f;
				glutPostRedisplay();
				break;

			//control hints/help
			case 'h': //print help
				printKeysHelp();
				break;
			case 'd': //print what is displayed
				printDispayedFeauters();
				break;


			//display objects
			case 'm':
				showWholeMesh^=true;
				glutPostRedisplay();
				break;
			case 'v':
				showVertexSurface^=true;
				glutPostRedisplay();
				break;
			case 'V':
				++VertexID;
				glutPostRedisplay();
				break;
			case 's':
				showQuadricSurface^=true;
				glutPostRedisplay();
				break;
			case 't':
				showTEST^=true;
				glutPostRedisplay();
				break;

			//annotation controls
			case 'a':
				showAxes^=true;
				glutPostRedisplay();
				break;
			case 'f':
				showFrame^=true;
				glutPostRedisplay();
				break;
			case 'b':
				showBox^=true;
				glutPostRedisplay();
				break;

			//some testing controls
			case 'x':
				glEnable(GL_FOG);
				glutPostRedisplay();
				break;
			case 'X':
				glDisable(GL_FOG);
				glutPostRedisplay();
				break;

			case 'i': //inspect a cell
				GetSceneViewSize(windowSizeX,windowSizeY, xVisF,xVisT,yVisF,yVisT);
				sx=(float)mx              /(float)windowSizeX * (xVisT-xVisF) + xVisF;
				sy=(float)(windowSizeY-my)/(float)windowSizeY * (yVisT-yVisF) + yVisF;

				xVisF=sx=sy; //just to avoid warning, TODO REMOVE
			/*
				for (c=agents.begin(); c != agents.end(); c++)
					if ((*c)->IsPointInCell(Vector3d<float>(sx,sy,0)))
					{
						bool wasSelected=(*c)->isSelected;
						(*c)->isSelected=true;
						(*c)->ReportState();
						(*c)->isSelected=wasSelected;
					}
			*/
				break;
    }
}


// called when a special key is pressed
void Skeyboard(int key, int mx, int my)
{
	key=mx=my; //TODO REMOVE
	mx=key;    //TODO REMOVE
/*
	//required for calculating the mouse position within the scene coords
	float xVisF, yVisF;
	float xVisT, yVisT;
	float sx,sy;

    switch (key) {
			case GLUT_KEY_LEFT:
				//rotate cell left by 30deg
				GetSceneViewSize(windowSizeX,windowSizeY, xVisF,xVisT,yVisF,yVisT);
				sx=(float)mx              /(float)windowSizeX * (xVisT-xVisF) + xVisF;
				sy=(float)(windowSizeY-my)/(float)windowSizeY * (yVisT-yVisF) + yVisF;

				for (c=agents.begin(); c != agents.end(); c++)
					if ((*c)->IsPointInCell(Vector3d<float>(sx,sy,0)))
					{
						(*c)->desiredDirection += PI/6.f;
						if ((*c)->desiredDirection > PI) 
							(*c)->desiredDirection -= 2.f*PI;
					}
				break;
			case GLUT_KEY_RIGHT:
				//rotate cell left by 30deg
				GetSceneViewSize(windowSizeX,windowSizeY, xVisF,xVisT,yVisF,yVisT);
				sx=(float)mx              /(float)windowSizeX * (xVisT-xVisF) + xVisF;
				sy=(float)(windowSizeY-my)/(float)windowSizeY * (yVisT-yVisF) + yVisF;

				for (c=agents.begin(); c != agents.end(); c++)
					if ((*c)->IsPointInCell(Vector3d<float>(sx,sy,0)))
					{
						(*c)->desiredDirection -= PI/6.f;
						if ((*c)->desiredDirection < -PI) 
							(*c)->desiredDirection += 2.f*PI;
					}
				break;
    }
*/
}

void mouse(int button, int state, int x, int y)
{
	if (state == GLUT_DOWN) MouseActive = true;
	else if (state == GLUT_UP) MouseActive = false;	
	
	last_x=button; //TODO REMOVE
	last_x = x;
	last_y = y;	
}

void MouseMotion(int x, int y) 
{
	if (MouseActive)
	{
		uhel_x -= (float(x - last_x) * 0.01f);
		uhel_y += (float(y - last_y) * 0.01f);
		
		last_x = x;
		last_y = y;

		glutPostRedisplay();
	}
}


// called when the window is reshaped, arguments are the new window size
void reshape(int w, int h)
{
    glViewport(0, 0, w, h);
    glMatrixMode(GL_PROJECTION);
    glLoadIdentity();

	 //remember the new window size...
	 windowSizeX=w; windowSizeY=h;

	 //what will be the final view port
    float xVisF, yVisF;
    float xVisT, yVisT;

	 GetSceneViewSize(w,h,xVisF,xVisT,yVisF,yVisT);
    
    //glOrtho(xVisF, xVisT, yVisF, yVisT, params.sceneCentre.z-params.sceneSize.z,params.sceneCentre.z+params.sceneSize.z);
    glOrtho(xVisF, xVisT, yVisF, yVisT, -1000,1000);
    glMatrixMode(GL_MODELVIEW);
}


void initializeGL(void)
{
	 int Argc=1;
	 char msg[]="meshSurface GUI";
	 char *Argv[10];
	 Argv[0]=msg;

    glutInit(&Argc, Argv);

    glutInitDisplayMode(GLUT_DOUBLE | GLUT_RGBA);
    //glutInitDisplayMode(GLUT_DOUBLE | GLUT_RGBA | GLUT_DEPTH);
    glutInitWindowSize(800, 800); 
    glutInitWindowPosition(600, 100);
    glutCreateWindow(Argv[0]);

    glutKeyboardFunc(keyboard);
    glutSpecialFunc(Skeyboard);
    glutDisplayFunc(display);
    glutReshapeFunc(reshape);

    glutMouseFunc(mouse);
    glutMotionFunc(MouseMotion);

    glClearColor(0.0, 0.0, 0.0, 0.0);

	 //enables alfa-blending for every object/drawing
    glEnable(GL_BLEND);
    glBlendFunc(GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA);

    glEnable(GL_POINT_SMOOTH);
    //glEnable(GL_CULL_FACE);
	 //glEnable(GL_DEPTH_TEST);

	 //enable fog:
	 //glEnable(GL_FOG);
	 glFogi(GL_FOG_MODE,GL_LINEAR);
	 GLfloat fogColor[4]={0.4f*params.sceneBorderColour.r,
	                      0.4f*params.sceneBorderColour.g,
	                      0.4f*params.sceneBorderColour.b,
								 1.0f}; //has no effect
	 glFogfv(GL_FOG_COLOR,fogColor);
	 //density is not required in linear mode
	 //glFogf(GL_FOG_DENSITY,0.3f);
	 //glHint(GL_FOG_HINT,GL_NICEST); //TODO adjust later

	 glFogf(GL_FOG_START,params.sceneOffset.z);
	 glFogf(GL_FOG_END,params.sceneOffset.z+params.sceneSize.z);
}

void loopGL(void)
{
	glutMainLoop();
}

void closeGL(void)
{
}