text: /*
   * Copyright (c) 1991, 1992, 1993 Silicon Graphics, Inc.
   *
   * Permission to use, copy, modify, distribute, and sell this software and
   * its documentation for any purpose is hereby granted without fee, provided
   * that (i) the above copyright notices and this permission notice appear in
   * all copies of the software and related documentation, and (ii) the name of
   * Silicon Graphics may not be used in any advertising or
   * publicity relating to the software without the specific, prior written
   * permission of Silicon Graphics.
   *
   * THE SOFTWARE IS PROVIDED "AS-IS" AND WITHOUT WARRANTY OF
   * ANY KIND,
   * EXPRESS, IMPLIED OR OTHERWISE, INCLUDING WITHOUT LIMITATION, ANY
   * WARRANTY OF MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE.
   *
   * IN NO EVENT SHALL SILICON GRAPHICS BE LIABLE FOR
   * ANY SPECIAL, INCIDENTAL, INDIRECT OR CONSEQUENTIAL DAMAGES OF ANY KIND,
   * OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS,
   * WHETHER OR NOT ADVISED OF THE POSSIBILITY OF DAMAGE, AND ON ANY THEORY OF
   * LIABILITY, ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE
   * OF THIS SOFTWARE.
   */
  
  /*
   * Nov 20, 1995 use stdlib's rand()/srand() instead of random()/srand48(), etc.
   */
  
  /*
   * Modified by Li Wei(liwei@aiar.xjtu.edu.cn) to be able to run in Windows
   * 6/13
   *
   * Modified by Brian Paul to compile with Windows OR Unix.  7/23/97
   */
  
  
  #define _HPUX_SOURCE
  
  #include <math.h>
  #include "basis.h"
  
  #ifndef RAND_MAX
  #  define RAND_MAX 32767
  #endif
  
  
  #define XSIZE  100
  #define YSIZE  75
  
  #define RINGS 5
  #define BLUERING 0
  #define BLACKRING 1
  #define REDRING 2
  #define YELLOWRING 3
  #define GREENRING 4
  
  #define BACKGROUND 8
  
  
  GLenum rgb, doubleBuffer;
  
  #include "tkmap.ch"
  
  unsigned char rgb_colors[RINGS][3];
  int mapped_colors[RINGS];
  float dests[RINGS][3];
  float offsets[RINGS][3];
  float angs[RINGS];
  float rotAxis[RINGS][3];
  int iters[RINGS];
  GLuint theTorus;
  
  
  void FillTorus(float rc, int numc, float rt, int numt)
  {
      int i, j, k;
      double s, t;
      double x, y, z;
      double pi, twopi;
  
      pi = 3.14159265358979323846;
      twopi = 2 * pi;
  
      for (i = 0; i < numc; i++) {
         glBegin(GL_QUAD_STRIP);
          for (j = 0; j <= numt; j++) {
             for (k = 1; k >= 0; k--) {
                 s = (i + k) % numc + 0.5;
                 t = j % numt;
  
                 x = cos(t*twopi/numt) * cos(s*twopi/numc);
                 y = sin(t*twopi/numt) * cos(s*twopi/numc);
                 z = sin(s*twopi/numc);
                 glNormal3f(x, y, z);
  
                 x = (rt + rc * cos(s*twopi/numc)) * cos(t*twopi/numt);
                 y = (rt + rc * cos(s*twopi/numc)) * sin(t*twopi/numt);
                 z = rc * sin(s*twopi/numc);
                 glVertex3f(x, y, z);
             }
          }
         glEnd();
      }
  }
  
  float Clamp(int iters_left, float t)
  {
  
      if (iters_left < 3) {
         return 0.0;
      }
      return (iters_left-2)*t/iters_left;
  }
  
  void GLUTCALLBACK  DrawScene(void)
  {
      int i, j;
      GLboolean goIdle;
  
      goIdle = GL_TRUE;
      for (i = 0; i < RINGS; i++) {
         if (iters[i]) {
             for (j = 0; j < 3; j++) {
                 offsets[i][j] = Clamp(iters[i], offsets[i][j]);
             }
             angs[i] = Clamp(iters[i], angs[i]);
             iters[i]--;
             goIdle = GL_FALSE;
         }
      }
      if (goIdle) {
         glutIdleFunc(NULL);
      }
  
      glPushMatrix();
  
      glClear(GL_COLOR_BUFFER_BIT|GL_DEPTH_BUFFER_BIT);
      gluLookAt(0,0,10, 0,0,0, 0,1,0);
  
      for (i = 0; i < RINGS; i++) {
         if (rgb) {
             glColor3ubv(rgb_colors[i]);
         } else {
             glIndexi(mapped_colors[i]);
         }
         glPushMatrix();
         glTranslatef(dests[i][0]+offsets[i][0], dests[i][1]+offsets[i][1],
                      dests[i][2]+offsets[i][2]);
         glRotatef(angs[i], rotAxis[i][0], rotAxis[i][1], rotAxis[i][2]);
         glCallList(theTorus);
         glPopMatrix();
      }
  
      glPopMatrix();
  
      glFlush();
      if (doubleBuffer) {
         glutSwapBuffers();
      }
  }
  
  float MyRand(void)
  {
     return 10.0 * ( (float) rand() / (float) RAND_MAX - 0.5 );
  }
  
  void GLUTCALLBACK glut_post_redisplay_p(void)
  {
        glutPostRedisplay();
  }
  
  void ReInit(void)
  {
      int i;
      float deviation;
  
      deviation = MyRand() / 2;
      deviation = deviation * deviation;
      for (i = 0; i < RINGS; i++) {
         offsets[i][0] = MyRand();
         offsets[i][1] = MyRand();
         offsets[i][2] = MyRand();
         angs[i] = 260.0 * MyRand();
         rotAxis[i][0] = MyRand();
         rotAxis[i][1] = MyRand();
         rotAxis[i][2] = MyRand();
         iters[i] = (deviation * MyRand() + 60.0);
      }
      glutIdleFunc(glut_post_redisplay_p);
  }
  
  void Init(void)
  {
      float base, height;
      float aspect, x, y;
      int i;
  
      float top_y = 1.0;
      float bottom_y = 0.0;
      float top_z = 0.15;
      float bottom_z = 0.69;
      float spacing = 2.5;
      static float lmodel_ambient[] = {0.0, 0.0, 0.0, 0.0};
      static float lmodel_twoside[] = {GL_FALSE};
      static float lmodel_local[] = {GL_FALSE};
      static float light0_ambient[] = {0.1, 0.1, 0.1, 1.0};
      static float light0_diffuse[] = {1.0, 1.0, 1.0, 0.0};
      static float light0_position[] = {0.8660254, 0.5, 1, 0};
      static float light0_specular[] = {1.0, 1.0, 1.0, 0.0};
      static float bevel_mat_ambient[] = {0.0, 0.0, 0.0, 1.0};
      static float bevel_mat_shininess[] = {40.0};
      static float bevel_mat_specular[] = {1.0, 1.0, 1.0, 0.0};
      static float bevel_mat_diffuse[] = {1.0, 0.0, 0.0, 0.0};
  
      srand( (unsigned int) glutGet(GLUT_ELAPSED_TIME) );
  
      ReInit();
      for (i = 0; i < RINGS; i++) {
         rgb_colors[i][0] = rgb_colors[i][1] = rgb_colors[i][2] = 0;
      }
      rgb_colors[BLUERING][2] = 255;
      rgb_colors[REDRING][0] = 255;
      rgb_colors[GREENRING][1] = 255;
      rgb_colors[YELLOWRING][0] = 255;
      rgb_colors[YELLOWRING][1] = 255;
      mapped_colors[BLUERING] = COLOR_BLUE;
      mapped_colors[REDRING] = COLOR_RED;
      mapped_colors[GREENRING] = COLOR_GREEN;
      mapped_colors[YELLOWRING] = COLOR_YELLOW;
      mapped_colors[BLACKRING] = COLOR_BLACK;
  
      dests[BLUERING][0] = -spacing;
      dests[BLUERING][1] = top_y;
      dests[BLUERING][2] = top_z;
  
      dests[BLACKRING][0] = 0.0;
      dests[BLACKRING][1] = top_y;
      dests[BLACKRING][2] = top_z;
  
      dests[REDRING][0] = spacing;
      dests[REDRING][1] = top_y;
      dests[REDRING][2] = top_z;
  
      dests[YELLOWRING][0] = -spacing / 2.0;
      dests[YELLOWRING][1] = bottom_y;
      dests[YELLOWRING][2] = bottom_z;
  
      dests[GREENRING][0] = spacing / 2.0;
      dests[GREENRING][1] = bottom_y;
      dests[GREENRING][2] = bottom_z;
  
      base = 2.0;
      height = 2.0;
      theTorus = glGenLists(1);
      glNewList(theTorus, GL_COMPILE);
      FillTorus(0.1, 8, 1.0, 25);
      glEndList();
  
      x = (float)XSIZE;
      y = (float)YSIZE;
      aspect = x / y;
      glEnable(GL_CULL_FACE);
      glCullFace(GL_BACK);
      glEnable(GL_DEPTH_TEST);
      glClearDepth(1.0);
  
      if (rgb) {
         glClearColor(0.5, 0.5, 0.5, 0.0);
         glLightfv(GL_LIGHT0, GL_AMBIENT, light0_ambient);
         glLightfv(GL_LIGHT0, GL_DIFFUSE, light0_diffuse);
         glLightfv(GL_LIGHT0, GL_SPECULAR, light0_specular);
         glLightfv(GL_LIGHT0, GL_POSITION, light0_position);
         glEnable(GL_LIGHT0);
  
         glLightModelfv(GL_LIGHT_MODEL_LOCAL_VIEWER, lmodel_local);
         glLightModelfv(GL_LIGHT_MODEL_TWO_SIDE, lmodel_twoside);
         glLightModelfv(GL_LIGHT_MODEL_AMBIENT, lmodel_ambient);
         glEnable(GL_LIGHTING);
  
         glMaterialfv(GL_FRONT, GL_AMBIENT, bevel_mat_ambient);
         glMaterialfv(GL_FRONT, GL_SHININESS, bevel_mat_shininess);
         glMaterialfv(GL_FRONT, GL_SPECULAR, bevel_mat_specular);
         glMaterialfv(GL_FRONT, GL_DIFFUSE, bevel_mat_diffuse);
  
         glColorMaterial(GL_FRONT_AND_BACK, GL_DIFFUSE);
         glEnable(GL_COLOR_MATERIAL);
         glShadeModel(GL_SMOOTH);
      } else {
         glClearIndex(BACKGROUND);
         glShadeModel(GL_FLAT);
      }
  
      glMatrixMode(GL_PROJECTION);
      gluPerspective(45, 1.33, 0.1, 100.0);
      glMatrixMode(GL_MODELVIEW);
  }
  
  void GLUTCALLBACK  Reshape(int width, int height)
  {
  
      glViewport(0, 0, width, height);
  }
  
  void GLUTCALLBACK  Key(unsigned char key, int x, int y)
  {
  
      switch (key) {
        case 27:
         exit(1);
        case 32:
         ReInit();
         break;
      }
  }
  
  GLenum Args(int argc, char **argv)
  {
      GLint i;
  
      rgb = GL_TRUE;
      doubleBuffer = GL_FALSE;
  
      for (i = 1; i < argc; i++) {
         if (strcmp(argv[i], "-ci") == 0) {
             rgb = GL_FALSE;
         } else if (strcmp(argv[i], "-rgb") == 0) {
             rgb = GL_TRUE;
         } else if (strcmp(argv[i], "-sb") == 0) {
             doubleBuffer = GL_FALSE;
         } else if (strcmp(argv[i], "-db") == 0) {
             doubleBuffer = GL_TRUE;
         } else if (strcmp(argv[i], "-?") == 0) {
             printf("Usage: olympic.exe [-ci|-rgb] [-sb|-db] [-?]\n");
         } else {
             printf("%s (Bad option).\n", argv[i]);
             return GL_FALSE;
         }
      }
   doubleBuffer = GL_TRUE;
      return GL_TRUE;
  }
  
  int maininit(int argc, char **argv)
  {
      GLenum type;
  
      glutInit(&argc, argv);
  
      if (Args(argc, argv) == GL_FALSE) {
         exit(1);
      }
  
  #if USE_MESA
      printf("Press Space or Esc\n"); fflush(stdout);
  #endif
      glutInitWindowPosition(0, 0); glutInitWindowSize( 400, 300);
  
      type = GLUT_DEPTH;
      type |= (rgb) ? GLUT_RGB : GLUT_INDEX;
      type |= (doubleBuffer) ? GLUT_DOUBLE : GLUT_SINGLE;
  
      glutInitDisplayMode(type);
  
      if (glutCreateWindow("Olympic") == GL_FALSE) {
          exit(1);
      }
  
      InitMap();
  
      Init();
  
      glutReshapeFunc(Reshape);
      glutKeyboardFunc(Key);
      glutDisplayFunc(DrawScene);
      glutIdleFunc(glut_post_redisplay_p);
  
      glutMainLoop();
         return 0;
  }
  