gears_sdl.c

/*
 * 3-D gear wheels.  This program is in the public domain.
 *
 * Command line options:
 *    -info      print GL implementation information
 *    -exit      automatically exit after 30 seconds
 *    -noanim    turn off animation
 *
 *
 * Brian Paul
 */

/* Conversion to GLUT by Mark J. Kilgard */



#include <math.h>
#include <stdlib.h>
#include <stdio.h>
#include <string.h>
#include <GL/gl.h>
#include <SDL2/SDL.h>

#ifndef M_PI
#define M_PI 3.14159265
#endif

static GLint T0 = 0;
static GLint Frames = 0;
static GLint autoexit = 0;
static GLint win = 0;
static GLboolean Visible = GL_TRUE;
static GLboolean Animate = GL_TRUE;
static GLfloat viewDist = 40.0;


/**

  Draw a gear wheel.  You'll probably want to call this function when
  building a display list since we do a lot of trig here.
 
  Input:  inner_radius - radius of hole at center
          outer_radius - radius at center of teeth
          width - width of gear
          teeth - number of teeth
          tooth_depth - depth of tooth

 **/

static void
gear(GLfloat inner_radius, GLfloat outer_radius, GLfloat width,
  GLint teeth, GLfloat tooth_depth)
{
  GLint i;
  GLfloat r0, r1, r2;
  GLfloat angle, da;
  GLfloat u, v, len;

  r0 = inner_radius;
  r1 = outer_radius - tooth_depth / 2.0;
  r2 = outer_radius + tooth_depth / 2.0;

  da = 2.0 * M_PI / teeth / 4.0;

  glShadeModel(GL_FLAT);

  glNormal3f(0.0, 0.0, 1.0);

  /* draw front face */
  glBegin(GL_QUAD_STRIP);
  for (i = 0; i <= teeth; i++) {
    angle = i * 2.0 * M_PI / teeth;
    glVertex3f(r0 * cos(angle), r0 * sin(angle), width * 0.5);
    glVertex3f(r1 * cos(angle), r1 * sin(angle), width * 0.5);
    if (i < teeth) {
      glVertex3f(r0 * cos(angle), r0 * sin(angle), width * 0.5);
      glVertex3f(r1 * cos(angle + 3 * da), r1 * sin(angle + 3 * da), width * 0.5);
    }
  }
  glEnd();

  /* draw front sides of teeth */
  glBegin(GL_QUADS);
  da = 2.0 * M_PI / teeth / 4.0;
  for (i = 0; i < teeth; i++) {
    angle = i * 2.0 * M_PI / teeth;

    glVertex3f(r1 * cos(angle), r1 * sin(angle), width * 0.5);
    glVertex3f(r2 * cos(angle + da), r2 * sin(angle + da), width * 0.5);
    glVertex3f(r2 * cos(angle + 2 * da), r2 * sin(angle + 2 * da), width * 0.5);
    glVertex3f(r1 * cos(angle + 3 * da), r1 * sin(angle + 3 * da), width * 0.5);
  }
  glEnd();

  glNormal3f(0.0, 0.0, -1.0);

  /* draw back face */
  glBegin(GL_QUAD_STRIP);
  for (i = 0; i <= teeth; i++) {
    angle = i * 2.0 * M_PI / teeth;
    glVertex3f(r1 * cos(angle), r1 * sin(angle), -width * 0.5);
    glVertex3f(r0 * cos(angle), r0 * sin(angle), -width * 0.5);
    if (i < teeth) {
      glVertex3f(r1 * cos(angle + 3 * da), r1 * sin(angle + 3 * da), -width * 0.5);
      glVertex3f(r0 * cos(angle), r0 * sin(angle), -width * 0.5);
    }
  }
  glEnd();

  /* draw back sides of teeth */
  glBegin(GL_QUADS);
  da = 2.0 * M_PI / teeth / 4.0;
  for (i = 0; i < teeth; i++) {
    angle = i * 2.0 * M_PI / teeth;

    glVertex3f(r1 * cos(angle + 3 * da), r1 * sin(angle + 3 * da), -width * 0.5);
    glVertex3f(r2 * cos(angle + 2 * da), r2 * sin(angle + 2 * da), -width * 0.5);
    glVertex3f(r2 * cos(angle + da), r2 * sin(angle + da), -width * 0.5);
    glVertex3f(r1 * cos(angle), r1 * sin(angle), -width * 0.5);
  }
  glEnd();

  /* draw outward faces of teeth */
  glBegin(GL_QUAD_STRIP);
  for (i = 0; i < teeth; i++) {
    angle = i * 2.0 * M_PI / teeth;

    glVertex3f(r1 * cos(angle), r1 * sin(angle), width * 0.5);
    glVertex3f(r1 * cos(angle), r1 * sin(angle), -width * 0.5);
    u = r2 * cos(angle + da) - r1 * cos(angle);
    v = r2 * sin(angle + da) - r1 * sin(angle);
    len = sqrt(u * u + v * v);
    u /= len;
    v /= len;
    glNormal3f(v, -u, 0.0);
    glVertex3f(r2 * cos(angle + da), r2 * sin(angle + da), width * 0.5);
    glVertex3f(r2 * cos(angle + da), r2 * sin(angle + da), -width * 0.5);
    glNormal3f(cos(angle), sin(angle), 0.0);
    glVertex3f(r2 * cos(angle + 2 * da), r2 * sin(angle + 2 * da), width * 0.5);
    glVertex3f(r2 * cos(angle + 2 * da), r2 * sin(angle + 2 * da), -width * 0.5);
    u = r1 * cos(angle + 3 * da) - r2 * cos(angle + 2 * da);
    v = r1 * sin(angle + 3 * da) - r2 * sin(angle + 2 * da);
    glNormal3f(v, -u, 0.0);
    glVertex3f(r1 * cos(angle + 3 * da), r1 * sin(angle + 3 * da), width * 0.5);
    glVertex3f(r1 * cos(angle + 3 * da), r1 * sin(angle + 3 * da), -width * 0.5);
    glNormal3f(cos(angle), sin(angle), 0.0);
  }

  glVertex3f(r1 * cos(0), r1 * sin(0), width * 0.5);
  glVertex3f(r1 * cos(0), r1 * sin(0), -width * 0.5);

  glEnd();

  glShadeModel(GL_SMOOTH);

  /* draw inside radius cylinder */
  glBegin(GL_QUAD_STRIP);
  for (i = 0; i <= teeth; i++) {
    angle = i * 2.0 * M_PI / teeth;
    glNormal3f(-cos(angle), -sin(angle), 0.0);
    glVertex3f(r0 * cos(angle), r0 * sin(angle), -width * 0.5);
    glVertex3f(r0 * cos(angle), r0 * sin(angle), width * 0.5);
  }
  glEnd();

}

static GLfloat view_rotx = 20.0, view_roty = 30.0, view_rotz = 0.0;
static GLint gear1, gear2, gear3;
static GLfloat angle = 0.0;

static void
cleanup(void)
{
   glDeleteLists(gear1, 1);
   glDeleteLists(gear2, 1);
   glDeleteLists(gear3, 1);
//    glutDestroyWindow(win);
}

static void
draw(void)
{
  glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);

  glPushMatrix();

    glTranslatef(0.0, 0.0, -viewDist);

    glRotatef(view_rotx, 1.0, 0.0, 0.0);
    glRotatef(view_roty, 0.0, 1.0, 0.0);
    glRotatef(view_rotz, 0.0, 0.0, 1.0);

    glPushMatrix();
      glTranslatef(-3.0, -2.0, 0.0);
      glRotatef(angle, 0.0, 0.0, 1.0);
      glCallList(gear1);
    glPopMatrix();

    glPushMatrix();
      glTranslatef(3.1, -2.0, 0.0);
      glRotatef(-2.0 * angle - 9.0, 0.0, 0.0, 1.0);
      glCallList(gear2);
    glPopMatrix();

    glPushMatrix();
      glTranslatef(-3.1, 4.2, 0.0);
      glRotatef(-2.0 * angle - 25.0, 0.0, 0.0, 1.0);
      glCallList(gear3);
    glPopMatrix();

  glPopMatrix();

//   glutSwapBuffers();
// SDL_GL_SwapBuffers();
  Frames++;

//   {
//     GLint t = glutGet(GLUT_ELAPSED_TIME);
//     if (t - T0 >= 5000) {
//       GLfloat seconds = (t - T0) / 1000.0;
//       GLfloat fps = Frames / seconds;
//       printf("%d frames in %6.3f seconds = %6.3f FPS\n", Frames, seconds, fps);
//       fflush(stdout);
//       T0 = t;
//       Frames = 0;
//       if ((t >= 999.0 * autoexit) && (autoexit)) {
//         cleanup();
//         exit(0);
//       }
//     }
//   }
}


static void
idle(void)
{
//   static double t0 = -1.;
//   double dt, t = glutGet(GLUT_ELAPSED_TIME) / 1000.0;
//   if (t0 < 0.0)
//     t0 = t;
//   dt = t - t0;
//   t0 = t;

//   angle += 70.0 * dt;  /* 70 degrees per second */
//   angle = fmod(angle, 360.0); /* prevents eventual overflow */

//   glutPostRedisplay();
}

static void
update_idle_func(void)
{
//   if (Visible && Animate)
//     glutIdleFunc(idle);
//   else
//     glutIdleFunc(NULL);
}

/* change view angle, exit upon ESC */
/* ARGSUSED1 */
static void
key(unsigned char k, int x, int y)
{
  switch (k) {
  case 'z':
    view_rotz += 5.0;
    break;
  case 'Z':
    view_rotz -= 5.0;
    break;
  case 'd':
     viewDist += 1.0;
     break;
  case 'D':
     viewDist -= 1.0;
     break;
  case 'a':
     Animate = !Animate;
     update_idle_func();
     break;
  case 27:  /* Escape */
    cleanup();
    exit(0);
    break;
  default:
    return;
  }
//   glutPostRedisplay();
}

/* change view angle */
/* ARGSUSED1 */
static void
special(int k, int x, int y)
{
//   switch (k) {
//   case GLUT_KEY_UP:
//     view_rotx += 5.0;
//     break;
//   case GLUT_KEY_DOWN:
//     view_rotx -= 5.0;
//     break;
//   case GLUT_KEY_LEFT:
//     view_roty += 5.0;
//     break;
//   case GLUT_KEY_RIGHT:
//     view_roty -= 5.0;
//     break;
//   default:
//     return;
//   }
//   glutPostRedisplay();
}

/* new window size or exposure */
static void
reshape(int width, int height)
{
  GLfloat h = (GLfloat) height / (GLfloat) width;

  glViewport(0, 0, (GLint) width, (GLint) height);
  glMatrixMode(GL_PROJECTION);
  glLoadIdentity();
  glFrustum(-1.0, 1.0, -h, h, 5.0, 200.0);
  glMatrixMode(GL_MODELVIEW);
}

static void
init(int argc, char *argv[])
{
  static GLfloat pos[4] = {5.0, 5.0, 10.0, 0.0};
  static GLfloat red[4] = {0.8, 0.1, 0.0, 1.0};
  static GLfloat green[4] = {0.0, 0.8, 0.2, 1.0};
  static GLfloat blue[4] = {0.2, 0.2, 1.0, 1.0};
  GLint i;

  glLightfv(GL_LIGHT0, GL_POSITION, pos);
  glEnable(GL_CULL_FACE);
  glEnable(GL_LIGHTING);
  glEnable(GL_LIGHT0);
  glEnable(GL_DEPTH_TEST);

  /* make the gears */
  gear1 = glGenLists(1);
  glNewList(gear1, GL_COMPILE);
  glMaterialfv(GL_FRONT, GL_AMBIENT_AND_DIFFUSE, red);
  gear(1.0, 4.0, 1.0, 20, 0.7);
  glEndList();

  gear2 = glGenLists(1);
  glNewList(gear2, GL_COMPILE);
  glMaterialfv(GL_FRONT, GL_AMBIENT_AND_DIFFUSE, green);
  gear(0.5, 2.0, 2.0, 10, 0.7);
  glEndList();

  gear3 = glGenLists(1);
  glNewList(gear3, GL_COMPILE);
  glMaterialfv(GL_FRONT, GL_AMBIENT_AND_DIFFUSE, blue);
  gear(1.3, 2.0, 0.5, 10, 0.7);
  glEndList();

  glEnable(GL_NORMALIZE);

  for ( i=1; i<argc; i++ ) {
    if (strcmp(argv[i], "-info")==0) {
      printf("GL_RENDERER   = %s\n", (char *) glGetString(GL_RENDERER));
      printf("GL_VERSION    = %s\n", (char *) glGetString(GL_VERSION));
      printf("GL_VENDOR     = %s\n", (char *) glGetString(GL_VENDOR));
      printf("GL_EXTENSIONS = %s\n", (char *) glGetString(GL_EXTENSIONS));
    }
    else if ( strcmp(argv[i], "-exit")==0) {
      autoexit = 30;
      printf("Auto Exit after %i seconds.\n", autoexit );
    }
    else if (strcmp(argv[i], "-noanim") == 0) {
      Animate = GL_FALSE;
    }
  }
}


static void 
visible(int vis)
{
   Visible = vis;
   update_idle_func();
}

// int main(int argc, char *argv[])
// {
//   glutInitWindowSize(300, 300);
//   glutInit(&argc, argv);
// //   glutInitContextVersion(3, 2);
//   glutInitDisplayMode(GLUT_RGB | GLUT_DEPTH | GLUT_DOUBLE);
//   win = glutCreateWindow("Gears");
//   init(argc, argv);
// 
//   glutDisplayFunc(draw);
//   glutReshapeFunc(reshape);
//   glutKeyboardFunc(key);
//   glutSpecialFunc(special);
//   glutVisibilityFunc(visible);
//   update_idle_func();
// 
//   glutMainLoop();
//   return 0;             /* ANSI C requires main to return int. */
// }

int main(int argc, char *argv[])
{
  SDL_Window* window = 0;
    SDL_GLContext contexteOpenGL = 0;
	
    SDL_Event evenements;
    int terminer = 0;
	
	
    // Initialisation de la SDL
	
    if(SDL_Init(SDL_INIT_VIDEO) < 0)
    {
//         std::cout << "Erreur lors de l'initialisation de la SDL : " << SDL_GetError() << std::endl;
        printf("err sdl init\n");
        SDL_Quit();
		
        return -1;
    }
	
	
    // Version d'OpenGL
	
    SDL_GL_SetAttribute(SDL_GL_CONTEXT_MAJOR_VERSION, 3);
    SDL_GL_SetAttribute(SDL_GL_CONTEXT_MINOR_VERSION, 2);
// 	SDL_GL_SetAttribute(SDL_GL_CONTEXT_PROFILE_MASK, SDL_GL_CONTEXT_PROFILE_CORE);
	
    // Double Buffer
	
    SDL_GL_SetAttribute(SDL_GL_DOUBLEBUFFER, 1);
    SDL_GL_SetAttribute(SDL_GL_DEPTH_SIZE, 24);
	
	
    // Création de la fenêtre

    window = SDL_CreateWindow("Test SDL 2.0", SDL_WINDOWPOS_CENTERED, SDL_WINDOWPOS_CENTERED, 800, 600, SDL_WINDOW_SHOWN| SDL_WINDOW_OPENGL|SDL_WINDOW_RESIZABLE);

    if(window == 0)
    {
//         std::cout << "Erreur lors de la creation de la window : " << SDL_GetError() << std::endl;
         printf("err win init\n");
        SDL_Quit();

        return -1;
    }


    // Création du contexte OpenGL

    contexteOpenGL = SDL_GL_CreateContext(window);

    if(contexteOpenGL == 0)
    {
//         std::cout << SDL_GetError() << std::endl;
         printf("err sdl init%s\n", SDL_GetError());
        SDL_DestroyWindow(window);
        SDL_Quit();

        return -1;
    }
    
    printf("ERRRR=%s\n", SDL_GetError());
	glClearColor(0,1,0,0.5);
glClear(GL_COLOR_BUFFER_BIT);
SDL_GL_SwapWindow(window);

	printf("GL_RENDERER   = %s\n", (char *) glGetString(GL_RENDERER));
      printf("GL_VERSION    = %s\n", (char *) glGetString(GL_VERSION));
      printf("GL_VENDOR     = %s\n", (char *) glGetString(GL_VENDOR));
      printf("GL_EXTENSIONS = %s\n", (char *) glGetString(GL_EXTENSIONS));
    // Boucle principale
	init(argc, argv);
  reshape(800, 600);
    while(!terminer)
    {
      draw();
      SDL_GL_SwapWindow(window);
      
        SDL_WaitEvent(&evenements);
		
        if(evenements.window.event == SDL_WINDOWEVENT_CLOSE)
        terminer = 1;
        
        
        static double t0 = -1.;
  double dt, t =  SDL_GetTicks() / 1000.0;
  if (t0 < 0.0)
    t0 = t;
  dt = t - t0;
  t0 = t;

  angle += 70.0 * dt;  /* 70 degrees per second */
  angle = fmod(angle, 360.0); /* prevents eventual overflow */
    }
	
	
    // On quitte la SDL
	
    SDL_GL_DeleteContext(contexteOpenGL);
    SDL_DestroyWindow(window);
    SDL_Quit();
	
    return 0;
}