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

#include "texture.h"

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

GLfloat xRot = -5.0f;
GLfloat yRot = 0.0f;

GLuint texture1;

double forog = 0.0;

void HengerPalast(int n, double radius1, double radius2, double height)
{
  /*
    n      - hany oldalu szabalyos sokszoggel kozelitunk (n legalább 3)
    radius - a sokszog kore irhato kor sugara
    x, y   - a sokszog kore irhato kor kozeppontjanak koordinatai
  */

  int i;
  double f;
  GLfloat angle;

  if(n < 3)
    n = 3;

  glBegin(GL_QUAD_STRIP);
  for(i = 0, angle = 0.0, f = 0.0; i <= n; i++, angle += 2.0 * GL_PI / n, f+= 1.0/n)
  {
      glTexCoord2f(f, 1.0);
      glVertex3f(radius1 * cos(angle), radius1 * sin(angle), height/2.0);
      glTexCoord2f(f, 0.0);
      glVertex3f(radius2 * cos(angle), radius2 * 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);

  glPushMatrix();
  glRotatef(xRot, 1.0f, 0.0f, 0.0f);
  glRotatef(yRot, 0.0f, 1.0f, 0.0f);

  // >> Modellezo programresz

  glEnable(GL_TEXTURE_2D);
  glBindTexture(GL_TEXTURE_2D, texture1);

  glPushMatrix();
    glTranslatef(-10, 0, 0);
    glRotatef(-forog, 0, 0, 1);
    HengerPalast(8, 5, 5, 20);
  glPopMatrix();

  glPushMatrix();
    glTranslatef(10, 0, 0);
    glRotatef(-forog, 0, 0, 1);
    HengerPalast(16, 4, 10, 10);
  glPopMatrix();

  glDisable(GL_TEXTURE_2D);

  // << Modellezo programresz

  glPopMatrix();

  // 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("DONOTENT.bmp", GL_FALSE, GL_LINEAR, GL_LINEAR, GL_REPEAT);
}

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)
    yRot -= 5.0f;

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

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

  if(xRot < 0.0f)
    xRot = 355.0f;

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

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

  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)
{
  forog += 5.0;
  if (forog > 355.0) forog = 0.0;

  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("GLUT Alap");

  // << Inicializalas

  // >> Callback fuggvenyek

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

  glutSpecialFunc(SpecialKeys);
  glutKeyboardFunc(Keyboard);
  glutDisplayFunc(RenderScene);
  glutTimerFunc(0, Timer, 1); // 1 mp mulva meghivodik a Timer() fuggveny
  //glutIdleFunc(Idle); // Idle(), ha nem tortenik semmi

  // << Callback fuggvenyek

  SetupRC();
  glutMainLoop();

  return 0;
}