/*
 *  legotown.cpp
 *  legotown3d
 *
 *  Created by Nico Bernold on 08.01.05.
 *  Copyright 2005 __MyCompanyName__. All rights reserved.
 *
 */

#include "heightMapViewer.h"

// constructor
HeightMapViewer::HeightMapViewer()
{
	cout << "HeightMapViewer::HeightMapViewer()" << endl;
	
	cameraPos = Vector(0,0,40);
	sightDirection = Vector(0,0,-1);

	lookAt = cameraPos + sightDirection;

	upVector = Vector(0,1,0);
	
	wireframe = false;
	mousedown = false;
	smoothShading = false;
	
}

// destructor
HeightMapViewer::~HeightMapViewer()
{
	cout << "HeightMapViewer::~HeightMapViewer()" << endl;
}

// main loop
bool HeightMapViewer::init(char* fileName)
{
        cout << "HeightMapViewer init()" << endl;
	
#ifdef FULLSCREEN
	if (!windowhandler.CreateGLWindow("height map viewer", WIDTH, HEIGHT, 32, true))
#else
	if (!windowhandler.CreateGLWindow("height map viewer", WIDTH, HEIGHT, 32, false))
#endif
	{
		cout << "could not create OpenGL-Window." << endl;
		return false;
	}

	if (terrain.loadBitmap(fileName) == false)
	{
		cout << "could not load bitmap." << endl;
		return false;
	}
	
	terrain.createDisplayLists(128, 128, 1);
	
	this->initLighting();
	SDL_EnableKeyRepeat(50,10);
	return true;
}

bool HeightMapViewer::initLighting(void)
{
  /*  glEnable(GL_LIGHTING);
  glEnable(GL_DEPTH_TEST);

  GLfloat whiteLight[] = {.2, .2, .2, 1.0};
  GLfloat light0Position[] = {10.0, 10.0, 10.0, 0.0};
  GLfloat lmodelAmbient[] = {.1, .1, .1, 1.0};

  glEnable(GL_LIGHT0);
  glLightfv(GL_LIGHT0, GL_POSITION, light0Position);
  glLightfv(GL_LIGHT0, GL_DIFFUSE, whiteLight);
  glLightfv(GL_LIGHT0, GL_SPECULAR, whiteLight);
  
	GLfloat klotz_Ka[]  = {0.2,0.2,0.2,1.0};
	GLfloat klotz_Kd[]  = {0.3,1.0,0.3,1.0};
	GLfloat klotz_Ks[]  = {0.8,0.8,0.8,1.0};
	GLfloat klotz_Ke[]  = {0.0,0.0,0.0,1.0};
	GLfloat klotz_Se    = 20;
	glMaterialfv(GL_FRONT,GL_AMBIENT,klotz_Ka);
	glMaterialfv(GL_FRONT,GL_DIFFUSE,klotz_Kd);
  */

	glShadeModel(GL_FLAT); // Enable Smooth Shading
	
	glClearColor(0.445f, 0.726f, 1.00f, 0.0f); // Blue Background
	
	glClearDepth(1.0f);  // Depth Buffer Setup
	glEnable(GL_DEPTH_TEST); // Enables Depth Testing
	glDepthFunc(GL_LEQUAL);	// The Type Of Depth Testing To Do

	glEnable(GL_CULL_FACE); // don't draw back faces
	
	glHint(GL_PERSPECTIVE_CORRECTION_HINT, GL_NICEST);  // Really Nice Perspective Calculations


	// fog behaves strange
	//glEnable(GL_FOG);
	GLfloat fog_color[4] = {0.7,0.7,0.7,1.0};
	glFogfv(GL_FOG_COLOR,fog_color);
	glFogf(GL_FOG_START, 0.0);
	glFogf(GL_FOG_END, 100.0);
	glFogi(GL_FOG_MODE,GL_LINEAR);


	glEnable(GL_NORMALIZE);
	
	// LIGHT SETTINGS
	glEnable(GL_LIGHTING);
	glEnable(GL_LIGHT0);
	
	// global parameters
	GLfloat global_Ka[]  = {0.25,0.25,0.25,1.0};
	
	// light0 parameters
	GLfloat light0_pos[] = {0.0,100.0,0.0,0.0};
	GLfloat light0_Ka[]  = {0.0,0.0,0.0,1.0};
	GLfloat light0_Kd[]  = {0.6,0.6,0.6,1.0};
	GLfloat light0_Ks[]  = {0.8,0.8,0.8,1.0};
	
	// klotz default parameters
	GLfloat klotz_Ka[]  = {0.2,0.2,0.2,1.0};
	GLfloat klotz_Kd[]  = {0.3,1.0,0.3,1.0};
	GLfloat klotz_Ks[]  = {0.8,0.8,0.8,1.0};
	GLfloat klotz_Ke[]  = {0.0,0.0,0.0,1.0};
	GLfloat klotz_Se    = 20;
	
	// set light0 options
	glLightfv(GL_LIGHT0,GL_POSITION,light0_pos);
	glLightfv(GL_LIGHT0,GL_AMBIENT,light0_Ka);
	glLightfv(GL_LIGHT0,GL_DIFFUSE,light0_Kd);
	glLightfv(GL_LIGHT0,GL_SPECULAR,light0_Ks);

	// MATERIAL SETTINGS
	glMaterialfv(GL_FRONT,GL_AMBIENT,klotz_Ka);
	glMaterialfv(GL_FRONT,GL_DIFFUSE,klotz_Kd);
	//glMaterialfv(GL_FRONT,GL_SPECULAR,klotz_Ks);
	//glMaterialfv(GL_FRONT,GL_EMISSION,klotz_Ke);
	//glMaterialf(GL_FRONT,GL_SHININESS,klotz_Se);


}


bool HeightMapViewer::run()
{
	cout << "HeightMapViewer run()" << endl;

	bool done = false;
	SDL_Event event;

	float angleX;
	float angleY;
	
	while(!done)
	{
		/* Check for events */
		while (SDL_PollEvent(&event))
		{
			switch (event.type)
			{
				case SDL_MOUSEMOTION:
					if (mousedown==true)
					{
						angleX = PI / 180 * event.motion.xrel * 0.2;
						angleY = PI / 180 * event.motion.yrel * 0.2;

						// Quaternion(angle,axis)
						rotator = Quaternion(-angleX,Vector(0,1,0));
						sightDirection = rotator.apply(sightDirection);

						rotator = Quaternion(angleY,perpendicular(sightDirection));
						
						sightDirection = rotator.apply(sightDirection);
						
						updateView();						
					}
					break;
				case SDL_MOUSEBUTTONDOWN:
					mousedown = true;
					break;
				case SDL_MOUSEBUTTONUP:
					mousedown = false;
					break;
					
				case SDL_KEYDOWN:

					switch(event.key.keysym.sym)
					{
						case SDLK_UP:
							// move in direction of sight
							cameraPos = cameraPos + sightDirection * 0.7;							
							updateView();
							break;

						case SDLK_DOWN:
							// move in direction of sight
							cameraPos = cameraPos - sightDirection * 0.7;
							updateView();
							break;
							
						case SDLK_LEFT:
							cameraPos = cameraPos + perpendicular(sightDirection) * 0.7;
							updateView();
							break;
							
						case SDLK_RIGHT:
							cameraPos = cameraPos - perpendicular(sightDirection) * 0.7;
							updateView();
							break;
							
						case SDLK_s:
							smoothShading = !smoothShading;
							if (smoothShading) 	glShadeModel(GL_SMOOTH);
							else glShadeModel(GL_FLAT);
							break;
							
						case SDLK_w:
							wireframe = !wireframe;
							if (wireframe) glPolygonMode(GL_FRONT_AND_BACK,GL_LINE);
							else glPolygonMode(GL_FRONT_AND_BACK,GL_FILL);
							break;
							
						case SDLK_r:
							// reset view vectors
							//cameraPos = Vector(0,0,40);
							//sightDirection = Vector(0,0,-1);							
							cameraPos = Vector(73.9871,172.496,286.137);
							sightDirection = Vector(0.23429,-0.736527,-0.625574);

							updateView();
							break;

						case SDLK_h:
							cout << "HELP\n"
							<< "display list count:    " << terrain.displayListCount << endl
							<< "first display list at: " << terrain.displayListStart << endl
							<< "camera position:       " << "(" << cameraPos.x << "," << cameraPos.y << "," << cameraPos.z << ")" << endl
							<< "sightDirection:        " << "(" << sightDirection.x << "," << sightDirection.y << "," << sightDirection.z << ")" << endl
							<< endl;
							
							break;
							
						case SDLK_ESCAPE:
						case SDLK_q:
							done = 1;
							break;
							
						default:
							break;
					}	
					break;
					
				case SDL_QUIT:
					done = 1;
					break;
					
				default:
					break;
			}
		}
		
		drawScene();

		SDL_GL_SwapBuffers();	

		SDL_Delay(1);
	}
	
	return true;
}

void HeightMapViewer::updateView()
{
	// be sure to use up to date lookAt-vector
	lookAt = cameraPos + sightDirection;
	upVector = sightDirection.cross(perpendicular(sightDirection));
	
	glMatrixMode(GL_PROJECTION); // Select The Projection Matrix
	glLoadIdentity();
	
	// Calculate The Aspect Ratio Of The Window
	gluPerspective(45.0f,(GLfloat)WIDTH/(GLfloat)HEIGHT,0.5f,300.0f);
	gluLookAt (cameraPos.x,cameraPos.y,cameraPos.z,
			   lookAt.x,lookAt.y,lookAt.z,
			   upVector.x,upVector.y,upVector.z);
	
	glMatrixMode(GL_MODELVIEW); // Select The Modelview Matrix
	glLoadIdentity(); // Reset The Modelview Matrix
}

void HeightMapViewer::drawScene()
{	
	glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);

	glPushMatrix();
	{
		//glTranslatef(0.0,1.0,0.0);
		glScalef(1,0.2,1);
	
		for (int i=0; i<terrain.displayListCount; i++)
		{
			glCallList(terrain.displayListStart + i);
		}
	}
	glPopMatrix();
	
	glColor3f(0.0,1.0,0.0);
	//	glutWireCube(1.0);
	
	glColor3f(0.0,0.0,1.0);
	glBegin(GL_POINTS);
	for (float z=0;z<10;z++)
		for (float x=0;x<10;x++)
			glVertex3f(x,0,z);
	glEnd();
	
}



/**
   \brief returns a vector that is perpendicular and lies in the xz-plane
 */
Vector perpendicular (Vector perpendic)
{
	Vector r;
	
	r.x =  perpendic.z;
	r.z = -perpendic.x;
	
	r.normalize();
	
	return r;	
}