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

#include "texture.h"

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

GLuint texture1;

static GLfloat xRot = 0.0;
static GLfloat zRot = 0.0;

static int N = 8;

void ConeApprox(int n, double radius, double height)
{
  int i;
  GLfloat angle;
  GLfloat f;

  if(n < 3)
    n = 3;
  
  glBegin(GL_TRIANGLE_FAN);
  glTexCoord2f( 0.5, 1.0 ); glVertex3f( 0.0, 0.0, height / 2.0 );
  for( i = 0, angle = 0.0, f = 0.0; i <= n; i++, angle += 2.0 * GL_PI / n, f += 1.0 / n )
  {
    glTexCoord2f( f, 0.0 );
    glVertex3f ( radius * cos( angle ), radius * sin( angle ), -height / 2.0 );
  }
  glEnd();
}

// Called to draw scene
void RenderScene(void)
{
  // Clear the window with current clearing color
  glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);

  // >> Modellezo programresz

  glPushMatrix();
  glRotatef(xRot, 1.0, 0.0, 0.0);
  glRotatef(zRot, 0.0, 0.0, 1.0);

  glColor3f(1.0, 1.0, 1.0);
  ConeApprox(N, 10.0, 20.0);
  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);

  texture1 = TextureLoad("kup_textura2.bmp", GL_FALSE, GL_LINEAR, GL_LINEAR, GL_REPEAT);
  
  glEnable(GL_TEXTURE_2D);
  glBindTexture(GL_TEXTURE_2D, texture1);
}

void SpecialKeys(int key, int x, int y)
{
  // ...
  int state;

  if(key == GLUT_KEY_UP)
    xRot-= 5.0f;
  
  if(key == GLUT_KEY_DOWN)
    xRot += 5.0f;
  
  if(key == GLUT_KEY_LEFT)
    zRot -= 5.0f;
  
  if(key == GLUT_KEY_RIGHT)
    zRot += 5.0f;
  
  if(xRot > 356.0f)
    xRot = 0.0f;
  
  if(xRot < -1.0f)
    xRot = 355.0f;
  
  if(zRot > 356.0f)
    zRot = 0.0f;
  
  if(zRot < -1.0f)
    zRot = 355.0f;

  if(key == GLUT_KEY_F1)
    N ++;

  if((key == GLUT_KEY_F2) && (N > 3))
    N --;

  /*
  printf("Funkciobillentyu lenyomva, kodja %d, pozicio (%d,%d). ", key, x, y);
  state = glutGetModifiers();
  if(state & GLUT_ACTIVE_SHIFT)
    printf("SHIFT lenyomva. ");
  if(state & GLUT_ACTIVE_CTRL)
    printf("CTRL lenyomva. ");
  if(state & GLUT_ACTIVE_ALT)
    printf("ALT lenyomva. ");
  printf("\n");
  fflush(stdout);

  // Refresh the Window
  glutPostRedisplay();
  */
}

void Keyboard(unsigned char key, int x, int y)
{
  // ...
  int state;

  /*
  printf("Billentyu lenyomva, kodja %c, pozicio (%d,%d). ", key, x, y);
  state = glutGetModifiers();
  if(state & GLUT_ACTIVE_SHIFT)
    printf("SHIFT lenyomva. ");
  if(state & GLUT_ACTIVE_CTRL)
    printf("CTRL lenyomva. ");
  if(state & GLUT_ACTIVE_ALT)
    printf("ALT lenyomva. ");
  printf("\n");
  fflush(stdout);


  glutPostRedisplay();
  */
}

void Timer(int value)
{
//  printf("Timer esemeny (%d)\n", value);
  
  glutPostRedisplay();
  glutTimerFunc(50, Timer, value + 1);
}

void Idle()
{

  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();
}

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

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

  // << Inicializalas

  // >> Callback fuggvenyek

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

  glutSpecialFunc(SpecialKeys);
//  glutKeyboardFunc(Keyboard);
  glutDisplayFunc(RenderScene);
  glutTimerFunc(1000, Timer, 1); // 1 mp mulva meghivodik a Timer() fuggveny
  //glutIdleFunc(Idle); // Idle(), ha nem tortenik semmi
  
  // << Callback fuggvenyek

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