/* Auteur: Nicolas JANEY         */
/* nicolas.janey@univ-fcomte.fr  */
/* Novembre 2005                 */
/* Illustration du trace         */
/* de cercle et de disque        */
/* par l'algorithme              */
/* de Bresenham (Midpoint)       */

#include <stdio.h>
#include <stdlib.h>
#include <math.h>

#include <GL/glut.h>
#include <GL/gl.h>
#include <GL/glu.h>

#include "ModuleCouleurs.h"
#include "ModuleMenus.h"
#include "ModuleReshape.h"
#include "ModuleFont.h"

#ifndef M_PI
#define M_PI 3.14159F
#endif

static int aff = 0;
static int r = 10;
static int yy = 0;
static int cc = 0;
static int c = 1;
static int f1;
static int fv;

void circle(int *p1,float r) {
  glColor4fv(couleurBleu());
  glBegin(GL_LINE_LOOP);
  for ( int i = 0; i < 360; i++ ) {
    float angle = i * M_PI / 180;
    float x = (float) (p1[0] + r*cos(angle));
    float y = (float) (p1[1] + r*sin(angle));
    glVertex2f(x,y); }
  glEnd();
}

void pixel(int x,int y,float *c) {
  glColor4fv(c);
  glBegin(GL_QUADS);
  glVertex2f(x-0.5F,y-0.5F);
  glVertex2f(x-0.5F,y+0.5F);
  glVertex2f(x+0.5F,y+0.5F);
  glVertex2f(x+0.5F,y-0.5F);
  glEnd();
  glColor4fv(couleurNoir());
  glBegin(GL_LINE_LOOP);
  glVertex2f(x-0.5F,y-0.5F);
  glVertex2f(x-0.5F,y+0.5F);
  glVertex2f(x+0.5F,y+0.5F);
  glVertex2f(x+0.5F,y-0.5F);
  glEnd();
}

void trame(int xi,int xf,int y,float *c) {
  for ( int i = xi; i <= xf; i++ )
    pixel(i,y,c);
}

int comptePixelsTrame(int xi,int xf) {
  return(xf-xi+1);
}

void pixelsSymetriques8(int x,int y,float *c) {
  pixel( x, y,c);
  pixel(-x, y,c);
  pixel( x,-y,c);
  pixel(-x,-y,c);
  pixel( y, x,c);
  pixel(-y, x,c);
  pixel( y,-x,c);
  pixel(-y,-x,c);
}

void pixelsSymetriques4(int x,int y,float *c) {
  pixel( x, y,c);
  pixel( x,-y,c);
  pixel( y, x,c);
  pixel(-y, x,c);
}

void pixelsSymetriques4(int cd,float *c) {
  pixel( cd, cd,c);
  pixel( cd,-cd,c);
  pixel(-cd, cd,c);
  pixel(-cd,-cd,c);
}

void cercle(float *c,int r) {
  int x,y,d;
  x = 0;
  y = r;
  d = 1 - r;
  if ( r == 0 ) {
    pixel(0,0,c);
    return; }
  pixelsSymetriques4(0,y,c);
  if ( r == 1 ) {
    return; }
  while ( y > x ) {
    if ( d < 0 )
      d += 2 * x + 3;
      else {
      d += 2 * (x - y) + 5;
      y--; }
    x++;
    if ( x < y )
      pixelsSymetriques8(x,y,c);
      else
      if ( x == y )
        pixelsSymetriques4(x,c); }
}

void cercleIncomplet(float *c,int r,int max) {
  int x,y,d;
  x = 0;
  y = r;
  d = 1 - r;
  if ( r == 0 ) {
    pixel(0,0,c);
    return; }
  pixelsSymetriques4(0,y,c);
  if ( r == 1 ) {
    return; }
  if ( r == 0 )
    return;
  int cp = 0;
  while ( ( y > x ) && ( cp < max ) ) {
    cp++;
    if ( d < 0 )
      d += 2 * x + 3;
      else {
      d += 2 * (x - y) + 5;
      y--; }
    x++;
    if ( x < y )
      pixelsSymetriques8(x,y,c);
      else
      if ( x == y )
        pixelsSymetriques4(x,c); }
}

void disque(float *c,int r) {
  int x,y,d;
  x = 0;
  y = r;
  d = 1 - r;
  if ( r == 0 ) {
    pixel(0,0,c);
    return; }
  if ( r == 1 ) {
    pixel(0,y,c);
    pixel(0,-y,c);
    return; }
  trame(-y,y,x,c);
  while ( y > x ) {
    if ( d < 0 )
      d += 2 * x + 3;
      else {
      if ( y > x ) {
        trame(-x,x,y,c);
        trame(-x,x,-y,c); }
      d += 2 * (x - y) + 5;
      y--; }
    x++;
    if ( y >= x ) {
      trame(-y,y,x,c);
      trame(-y,y,-x,c); } }
}

void disqueIncomplet(float *c,int r,int max) {
  int x,y,d;
  x = 0;
  y = r;
  d = 1 - r;
  if ( r == 0 ) {
    pixel(0,0,c);
    return; }
  if ( r == 1 ) {
    pixel(0,y,c);
    pixel(0,-y,c);
    return; }
  trame(-y,y,x,c);
  int cp = 0;
  while ( ( y > x ) && ( cp < max ) ) {
    cp++;
    if ( d < 0 )
      d += 2 * x + 3;
      else {
      if ( y > x ) {
        trame(-x,x,y,c);
        trame(-x,x,-y,c); }
      d += 2 * (x - y) + 5;
      y--; }
    x++;
    if ( y >= x ) {
      trame(-y,y,x,c);
      trame(-y,y,-x,c); } }
}

void display() {
  int p[] = { 0,0 };
  glClear(GL_COLOR_BUFFER_BIT|GL_DEPTH_BUFFER_BIT);
  glPushMatrix();
  switch (aff) {
    case 0 : if ( ( cc == 1 ) || ( cc == 2 ) )
               disque(couleurVert(),r);
             if ( ( cc == 0 ) || ( cc == 2 ) )
               cercle(couleurRouge(),r);
             if ( c )
               circle(p,r);
             break;
    case 1 : if ( ( cc == 1 ) || ( cc == 2 ) )
               disqueIncomplet(couleurVert(),r,yy);
             if ( ( cc == 0 ) || ( cc == 2 ) )
               cercleIncomplet(couleurRouge(),r,yy);
             if ( c )
               circle(p,r);
             break; }
  glPopMatrix();
  glFlush();
  glutSwapBuffers();
}

void myinit() {
  glShadeModel(GL_SMOOTH);
  glClearColor(0.8F,0.8F,0.8F,1.0F);
}

void postRedisplay() {
  glutPostWindowRedisplay(f1);
  glutPostWindowRedisplay(fv);
}

void key(unsigned char key,int x,int y) {
  switch ( key ) {
    case 'r'  : r--;
                if ( r < 0 )
                  r = 0;
                postRedisplay();
                break;
    case 'R'  : r++;
                if ( r > 28 )
                  r = 28;
                postRedisplay();
                break;
    case 'c'  :
    case 'C'  : c = !c;
                postRedisplay();
                break;
    case ' '  : cc = (cc+1)%3;
                postRedisplay();
                break;
    case 43   : yy++;
                if ( yy == 60 )
                  yy = 0;
                postRedisplay();
                break;
    case 45   : yy--;
                if ( yy == -1 )
                  yy = 0;
                postRedisplay();
                break;
    case 0x0D : yy = 0;
                aff = !aff;
                postRedisplay();
                break;
    case 0x1B : exit(0);
                break; }
}

int comptePixelsCercle(int r) {
  int x,y,d;
  x = 0;
  y = r;
  d = 1 - r;
  if ( r == 0 ) {
    return(1); }
  if ( r == 1 ) {
    return(4); }
  int cpt = 4;
  while ( y > x ) {
    if ( d < 0 )
      d += 2 * x + 3;
      else {
      d += 2 * (x - y) + 5;
      y--; }
    x++;
    if ( x < y )
      cpt += 8;
      else
      if ( x == y )
        cpt += 4; }
  return(cpt);
}

int comptePixelsCercleIncomplet(int r,int max) {
  int x,y,d;
  x = 0;
  y = r;
  d = 1 - r;
  if ( r == 0 ) {
    return(1); }
  if ( r == 1 ) {
    return(4); }
  int cpt = 4;
  int cp = 0;
  while ( ( y > x ) && ( cp < max ) ) {
    cp++;
    if ( d < 0 )
      d += 2 * x + 3;
      else {
      d += 2 * (x - y) + 5;
      y--; }
    x++;
    if ( x < y )
      cpt += 8;
      else
      if ( x == y )
        cpt += 4; }
  return(cpt);
}

int comptePixelsDisque(int r) {
  int x,y,d;
  x = 0;
  y = r;
  d = 1 - r;
  if ( r == 0 ) {
    return(1); }
  if ( r == 1 ) {
    return(5); }
  int cpt = comptePixelsTrame(-y,y);
  while ( y > x ) {
    if ( d < 0 )
      d += 2 * x + 3;
      else {
      if ( y > x ) {
        cpt += comptePixelsTrame(-x,x);
        cpt += comptePixelsTrame(-x,x); }
      d += 2 * (x - y) + 5;
      y--; }
    x++;
    if ( y >= x ) {
      cpt += comptePixelsTrame(-y,y);
      cpt += comptePixelsTrame(-y,y); } }
  return(cpt);
}

int comptePixelsDisqueIncomplet(int r,int max) {
  int x,y,d;
  x = 0;
  y = r;
  d = 1 - r;
  if ( r == 0 ) {
    return(1); }
  if ( r == 1 ) {
    return(5); }
  int cpt = comptePixelsTrame(-y,y);
  int cp = 0;
  while ( ( y > x ) && ( cp < max ) ) {
    cp++;
    if ( d < 0 )
      d += 2 * x + 3;
      else {
      if ( y > x ) {
        cpt += comptePixelsTrame(-x,x);
        cpt += comptePixelsTrame(-x,x); }
      d += 2 * (x - y) + 5;
      y--; }
    x++;
    if ( y >= x ) {
      cpt += comptePixelsTrame(-y,y);
      cpt += comptePixelsTrame(-y,y); } }
  return(cpt);
}

void displayV(void) {
  glClearColor(0.0F,0.0F,0.0F,1.0F) ;
  glClear(GL_DEPTH_BUFFER_BIT|GL_COLOR_BUFFER_BIT);
  glPushMatrix();
  float pos = 1.0F;
  glColor4fv(couleurBlanc());
  placeFontCursor(5.0F,-pos*20.0F,0.0F) ;
  simpleBitmapOutput(1,REGULAR8x13,"RAYON            : %6d",r);
  pos += 1.0F;
  switch (aff) {
    case 0 : if ( ( cc == 0 ) || ( cc == 2 ) ) {
               placeFontCursor(5.0F,-pos*20.0F,0.0F) ;
               simpleBitmapOutput(1,
                                  REGULAR8x13,
                                  "2*PI*R           : %9.2f",
                                  2*M_PI*r);
               pos += 1.0F;
               placeFontCursor(5.0F,-pos*20.0F,0.0F) ;
               simpleBitmapOutput(1,
                                  REGULAR8x13,
                                  "PIXELS DU CERCLE : %6d",
                                  comptePixelsCercle(r));
               pos += 1.0F; }
             if ( ( cc == 1 ) || ( cc == 2 ) ) {
               placeFontCursor(5.0F,-pos*20.0F,0.0F) ;
               simpleBitmapOutput(1,
                                  REGULAR8x13,
                                  "PI*R*R           : %9.2f",
                                  M_PI*r*r);
               pos += 1.0F;
               placeFontCursor(5.0F,-pos*20.0F,0.0F) ;
               simpleBitmapOutput(1,
                                  REGULAR8x13,
                                  "PIXELS DU DISQUE : %6d",
                                  comptePixelsDisque(r));
               pos += 1.0F; }
             break;
    case 1 : if ( ( cc == 0 ) || ( cc == 2 ) ) {
               placeFontCursor(5.0F,-pos*20.0F,0.0F) ;
               simpleBitmapOutput(1,
                                  REGULAR8x13,
                                  "PIXELS DU CERCLE : %6d",
                                  comptePixelsCercleIncomplet(r,yy));
               pos += 1.0F; }
             if ( ( cc == 1 ) || ( cc == 2 ) ) {
               placeFontCursor(5.0F,-pos*20.0F,0.0F) ;
               simpleBitmapOutput(1,
                                  REGULAR8x13,
                                  "PIXELS DU DISQUE : %6d",
                                  comptePixelsDisqueIncomplet(r,yy));
               pos += 1.0F; }
             break; }
  glPopMatrix();
  glFlush();
  glutSwapBuffers();
}

void reshapeV(int w,int h) {
  glViewport(0,0,w,h);
  glMatrixMode(GL_PROJECTION);
  glLoadIdentity();
  glOrtho(0,w,-h,0,-1.0,1.0); 
  glMatrixMode(GL_MODELVIEW);
  glLoadIdentity();
}

int main(int argc,char **argv) {
  glutInit(&argc,argv);
  { glutInitDisplayMode(GLUT_RGBA|GLUT_DEPTH|GLUT_DOUBLE);
    glutInitWindowSize(300,300); 
    glutInitWindowPosition(50,50); 
    f1 = glutCreateWindow("Cercle et disque par Bresenham"); 
    myinit(); 
    creationMenuBasique();
    setParametresOrthoBasique(-30.0,30.0,-30.0,30.0,-40.0,40.0);
    glutReshapeFunc(reshapeOrthoBasique);
    glutKeyboardFunc(key);
    glutDisplayFunc(display); }
  { glutInitWindowSize(300,70);
    glutInitWindowPosition(50,380);
    glutInitDisplayMode(GLUT_RGBA|GLUT_DEPTH|GLUT_DOUBLE);
    fv = glutCreateWindow("Valeurs");
    creationMenuBasique();
    glutDisplayFunc(displayV);
    glutReshapeFunc(reshapeV);
    glutKeyboardFunc(key); }
  glutMainLoop();
  return(0);
}