/*
 * triangle.c -- A simple example of OpenGL and GLUT.
 */

#include <GL/glut.h>

/******HERE INSERTING EMITSTRING FUNCTION*********/
#define RUL_H 20
                                                                               
#define FONT                    GLUT_BITMAP_8_BY_13
#define CHAR_W                  8
#define CHAR_H                  13
#define CHAR_DESCENT            3
#define LINE_SEP                2
#define CARRIAGE_RETURN         13
#define BACK_SPACE              8

static int toggle = 1;

/* emitString(s, x, y) -- displays string s at location x,y  */
void emitString(char *s, int tx, int ty)
{
  int x,y;
                                                                               
  x = tx;
  y = ty;
  while( *s ) {
    if( *s == CARRIAGE_RETURN ) {
      x = tx;
      y += CHAR_H + LINE_SEP;
    } else {
      glRasterPos2i(x,y);
      glutBitmapCharacter(FONT,*s);
      x += CHAR_W;
   }
    ++s;
  }
}

void drawDisk() {
    GLUquadricObj *qobj;
    GLdouble innerRadius = 0;
    GLdouble outerRadius = 100;
    GLint slices = 30;
    GLint loops = 2;
                                                                                                                                   
 //   glColor3f(1, 0, 0);
    qobj = gluNewQuadric();
    gluDisk(qobj, innerRadius, outerRadius, slices, loops);
}


/************************************************/



void displayCB(void)            /* function called whenever redisplay needed */
{
  glClear(GL_COLOR_BUFFER_BIT);         /* clear the display */
  glColor3f(1.0, 1.0, 1.0);             /* set current color to white */
  glBegin(GL_POLYGON);                  /* draw filled triangle */
  glVertex2i(200,125);                  /* specify each vertex of triangle */
  glVertex2i(100,375);
  glVertex2i(300,375);
  glEnd();                              /* OpenGL draws the filled triangle */
  
  glColor3f(1, 0, 0);
 // emitString("Hello! I am an example!",100,250); 
  if(toggle) {  glPushMatrix();
      glTranslatef(200, 200, 0);
      drawDisk();
      glPopMatrix();
  }
  glFlush();                            /* Complete any pending operations */
}

void keyCB(unsigned char key, int x, int y)     /* called on key press */
{
  if( key == 'q' ) exit(0);
  else if(key == 't') {
      toggle = !(toggle);
     glutPostRedisplay();
  }
}


int main(int argc, char *argv[])
{
  int win;

  glutInit(&argc, argv);                /* initialize GLUT system */

  glutInitDisplayMode(GLUT_RGB);
  glutInitWindowSize(400,500);          /* width=400pixels height=500pixels */
  win = glutCreateWindow("Triangle");   /* create window */

  /* from this point on the current window is win */

  glClearColor(0.0,0.0,0.0,0.0);        /* set background to black */
  gluOrtho2D(0,400,0,500);              /* how object is mapped to window */
 //ortho2(XMIN - 0.5, XMAX + 0.5, YMIN - 0.5, YMAX + 0.5);
 glutDisplayFunc(displayCB);           /* set window's display callback */
  glutKeyboardFunc(keyCB);              /* set window's key callback */

  glutMainLoop();                       /* start processing events... */

  /* execution never reaches this point */

  return 0;
}