/*
  Nev, ETR azonosito:
*/

#include <GL/glut.h>
#include <math.h>
#include <stdio.h>
#include <stdlib.h>

// Define a constant for the value of PI
#define GL_PI 3.1415f

static int MenuID, IdleMenu;
static int IdlePrint = 0;

static GLfloat xRot = 0.0, yRot = 0.0;

/*
  Teendok:
    - normalvektorok beallitasa
    - textura koordinatak beallitasa
*/
void CylinderApprox(int n, double radius, double height)
{
  int i, j;
  GLfloat angle;
  GLdouble stack_step, stack_actual;

  if(n < 3)
    n = 3;

  glBegin(GL_QUAD_STRIP);
  for(i = 0, angle = 0.0; i <= n; i++, angle += 2.0 * GL_PI / n)
    {
      glVertex3f(radius * cos(angle), radius * sin(angle), height / 2.0);
      glVertex3f(radius * cos(angle), radius * sin(angle), -height / 2.0);
    }
  glEnd();
}

/*
  Teendok:
    - normalvektor beallitasa
    - textura koordinatak beallitasa
*/
void Tabla()
{
  glPushMatrix();
  glTranslatef(0.0, 0.0, 1.0);

  glBegin(GL_TRIANGLES);
  glVertex3f(-6.0, -6.0, 0.0);
  glVertex3f(6.0, -6.0, 0.0);
  glVertex3f(0.0, 6.0, 0.0);
  glEnd();

  glPopMatrix();
}

// Called to draw scene
void RenderScene(void)
{
  GLfloat x,y, x2, y2, angle;  // Storage for coordinates and angles
  int iPivot = 1;		// Used to flag alternating colors 
  int i;

  // Clear the window with current clearing color
  glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);

  // >> Modellezo programresz
  glColor3f(1.0, 1.0, 1.0);
 
  glPushMatrix();
  glRotatef(xRot, 1.0f, 0.0f, 0.0f);
  glRotatef(yRot, 0.0f, 1.0f, 0.0f); 

  /*
    Tabla
    - Erre keruljon a korforgalom.bmp minta
      megfelelo resze kivagva.
    - Legyen 30%-ban atlatszo, ami ki/bekacsolhato az F1/F2-vel.
  */  
  glColor3f(1.0, 1.0, 1.0);
  glPushMatrix();
  glTranslatef(0.0, 5.0, 0.0);
  Tabla();
  glPopMatrix();

  /*
    Tartooszlop
    Erre keruljon a metal_texture2 minta.
  */
  glPushMatrix();
  glTranslatef(0.0, -5.0, 0.0);
  glRotatef(90.0, 1.0, 0.0, 0.0);
  CylinderApprox(32, 0.8, 28.0);
  glPopMatrix();

  glPopMatrix();
  
  // << Modellezo programresz
  
  // Flush drawing commands
  glutSwapBuffers();
}

// This function does any needed initialization on the rendering
// context. 
void SetupRC()
{
  // Black background
  glClearColor(0.0f, 0.0f, 0.0f, 1.0f );

  glEnable(GL_DEPTH_TEST);
}

void SpecialKeys(int key, int x, int y)
{
	if(key == GLUT_KEY_UP)
		xRot-= 5.0f;

	if(key == GLUT_KEY_DOWN)
		xRot += 5.0f;

	if(key == GLUT_KEY_LEFT)
		yRot -= 5.0f;

	if(key == GLUT_KEY_RIGHT)
		yRot += 5.0f;

	if(xRot > 356.0f)
		xRot = 0.0f;

	if(xRot < -1.0f)
		xRot = 355.0f;

	if(yRot > 356.0f)
		yRot = 0.0f;

	if(yRot < -1.0f)
		yRot = 355.0f;

	// Refresh the Window
	glutPostRedisplay();
	}
  
void ChangeSizeOrtho(int w, int h)
{
  GLfloat nRange = 25.0f;
  
  // Prevent a divide by zero
  if(h == 0)
    h = 1;
  
  // Set Viewport to window dimensions
  glViewport(0, 0, w, h);
  
  // Reset projection matrix stack
  glMatrixMode(GL_PROJECTION);
  glLoadIdentity();
  
  // Establish clipping volume (left, right, bottom, top, near, far)
  if (w <= h) 
    glOrtho (-nRange, nRange, -nRange*h/w, nRange*h/w, -nRange, nRange);
  else 
    glOrtho (-nRange*w/h, nRange*w/h, -nRange, nRange, -nRange, nRange);
  
  // Reset Model view matrix stack
  glMatrixMode(GL_MODELVIEW);
  glLoadIdentity();
}

void ChangeSizePerspective(GLsizei w, GLsizei h)
{
  GLfloat fAspect;
  
  // Prevent a divide by zero
  if(h == 0)
    h = 1;
  
  // Set Viewport to window dimensions
  glViewport(0, 0, w, h);
  
  fAspect = (GLfloat)w/(GLfloat)h;
  
  // Reset coordinate system
  glMatrixMode(GL_PROJECTION);
  glLoadIdentity();
  
  // Produce the perspective projection
  gluPerspective(60.0f,    // fovy
		 fAspect,  // aspect
		 10.0,     // zNear
		 100.0     // zFar
		 );
  gluLookAt(0.0, 0.0, 50.0, // eye
	    0.0, 0.0, 0.0,  // center
	    0.0, 1.0, 0.0   // up
	    );
  
  glMatrixMode(GL_MODELVIEW);
  glLoadIdentity();
}

void ProcessMenu(int value)
{
  switch(value)
    {
    case 1:
      printf("1. menupont kivalasztva.\n");
      break;
      
    case 2:
      printf("2. menupont kivalasztva.\n");
      break;
      
    case 3:
      printf("Idle kiiratas bekapcsolva.\n");
      IdlePrint = 1;
      break;

    case 4:
      printf("Idle kiiratas kikapcsolva.\n");
      IdlePrint = 0;
      break;
      
    case 5:
      exit(0);

    default:
      break;
    }
  
  glutPostRedisplay();
}

int main(int argc, char* argv[])
{
  // >> Inicializalas

  glutInit(&argc, argv);
  glutInitDisplayMode(GLUT_DOUBLE | GLUT_RGB | GLUT_DEPTH);
  //glutInitWindowSize(300, 300);
  glutCreateWindow("GLUT Alap");

  // << Inicializalas

  // >> Callback fuggvenyek

  glutReshapeFunc(ChangeSizeOrtho); // Parhuzamos vetites
  //glutReshapeFunc(ChangeSizePerspective); // Perspektiv vetites

  glutSpecialFunc(SpecialKeys);
  glutDisplayFunc(RenderScene);
  
  // << Callback fuggvenyek

  // >> Menu

  IdleMenu = glutCreateMenu(ProcessMenu);
  glutAddMenuEntry("Idle kiiratas bekapcsolasa", 3);
  glutAddMenuEntry("Idle kiiratas kikapcsolasa", 4);

  MenuID = glutCreateMenu(ProcessMenu);
  glutAddMenuEntry("1. menupont", 1);
  glutAddMenuEntry("2. menupont", 2);
  glutAddSubMenu("Idle fuggveny", IdleMenu);
  glutAddMenuEntry("Kilepes", 5);
  glutAttachMenu(GLUT_RIGHT_BUTTON);

  // << Menu

  SetupRC();
  glutMainLoop();
  
  return 0;
}