/*
 * (c) Copyright 1993, Silicon Graphics, Inc.
 * ALL RIGHTS RESERVED 
 * Permission to use, copy, modify, and distribute this software for 
 * any purpose and without fee is hereby granted, provided that the above
 * copyright notice appear in all copies and that both the copyright notice
 * and this permission notice appear in supporting documentation, and that 
 * the name of Silicon Graphics, Inc. not be used in advertising
 * or publicity pertaining to distribution of the software without specific,
 * written prior permission. 
 *
 * THE MATERIAL EMBODIED ON THIS SOFTWARE IS PROVIDED TO YOU "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, INC.  BE LIABLE TO YOU OR ANYONE ELSE FOR ANY DIRECT,
 * SPECIAL, INCIDENTAL, INDIRECT OR CONSEQUENTIAL DAMAGES OF ANY
 * KIND, OR ANY DAMAGES WHATSOEVER, INCLUDING WITHOUT LIMITATION,
 * LOSS OF PROFIT, LOSS OF USE, SAVINGS OR REVENUE, OR THE CLAIMS OF
 * THIRD PARTIES, WHETHER OR NOT SILICON GRAPHICS, INC.  HAS BEEN
 * ADVISED OF THE POSSIBILITY OF SUCH LOSS, HOWEVER CAUSED AND ON
 * ANY THEORY OF LIABILITY, ARISING OUT OF OR IN CONNECTION WITH THE
 * POSSESSION, USE OR PERFORMANCE OF THIS SOFTWARE.
 * 
 * US Government Users Restricted Rights 
 * Use, duplication, or disclosure by the Government is subject to
 * restrictions set forth in FAR 52.227.19(c)(2) or subparagraph
 * (c)(1)(ii) of the Rights in Technical Data and Computer Software
 * clause at DFARS 252.227-7013 and/or in similar or successor
 * clauses in the FAR or the DOD or NASA FAR Supplement.
 * Unpublished-- rights reserved under the copyright laws of the
 * United States.  Contractor/manufacturer is Silicon Graphics,
 * Inc., 2011 N.  Shoreline Blvd., Mountain View, CA 94039-7311.
 *
 * OpenGL(TM) is a trademark of Silicon Graphics, Inc.
 */
/*
 *  tea.c
 *  This program demonstrates two-sided lighting and compares
 *  it with one-sided lighting.  Three teapots are drawn, with
 *  a clipping plane to expose the interior of the objects.
 */

#include "windows.h"

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

#include <stdio.h>

static float anglex = 0.0F ;
static float angley = 0.0F ;

void myinit(void) {
  GLfloat light_ambient[] = { 0.0F,0.0F,0.0F,1.0F };
  GLfloat light_diffuse[] = { 1.0F,1.0F,1.0F,1.0F };
  GLfloat light_specular[] = { 1.0F,1.0F,1.0F,1.0F };
  GLfloat light_position[] = { 1.0F,1.0F,1.0F,0.0F };
  glLightfv(GL_LIGHT0,GL_AMBIENT,light_ambient);
  glLightfv(GL_LIGHT0,GL_DIFFUSE,light_diffuse);
  glLightfv(GL_LIGHT0,GL_SPECULAR,light_specular);
  glLightfv(GL_LIGHT0,GL_POSITION,light_position);
  glFrontFace(GL_CW);
  glEnable(GL_LIGHTING);
  glEnable(GL_LIGHT0);
  glEnable(GL_AUTO_NORMAL);
  glEnable(GL_NORMALIZE);
  glDepthFunc(GL_LESS);
  glEnable(GL_DEPTH_TEST);
}

void CALLBACK display(void) {
  GLdouble eqn[4] = {1.0,0.0,-1.0,1.0};
  GLfloat two_side_on[] = { GL_TRUE };
  GLfloat two_side_off[] = { GL_FALSE };
  GLfloat mat_diffuse[] = { 0.8F,0.8F,0.8F,1.0F };
  GLfloat back_diffuse[] = { 0.8F,0.2F,0.8F,1.0F };
  glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
  glPushMatrix();
  glRotatef(angley,0.0F,1.0F,0.0F) ;
  glRotatef(anglex,1.0F,0.0F,0.0F) ;
  glPushMatrix();
  glClipPlane(GL_CLIP_PLANE0,eqn);
  glEnable(GL_CLIP_PLANE0); 
  glPushMatrix();
  glTranslatef(0.0F,2.0F,0.0F);
  auxSolidTeapot(1.0);
  glPopMatrix();
  glLightModeli(GL_LIGHT_MODEL_TWO_SIDE,GL_TRUE);
  glMaterialfv(GL_FRONT_AND_BACK,GL_DIFFUSE,mat_diffuse);
  glPushMatrix();
  glTranslatef(0.0F,0.0F,0.0F);
  auxSolidTeapot(1.0);
  glPopMatrix();
  glMaterialfv(GL_FRONT,GL_DIFFUSE,mat_diffuse);
  glMaterialfv(GL_BACK,GL_DIFFUSE,back_diffuse);
  glPushMatrix();
  glTranslatef(0.0F,-2.0F,0.0F);
  auxSolidTeapot(1.0);
  glPopMatrix();
  glLightModeli(GL_LIGHT_MODEL_TWO_SIDE,GL_FALSE);
  glDisable(GL_CLIP_PLANE0);
  glPopMatrix();
  glPopMatrix();
  glFlush();
  auxSwapBuffers();
}

void CALLBACK myReshape(int w,int h) {
  glViewport(0,0,w,h);
  glMatrixMode(GL_PROJECTION);
  glLoadIdentity();
  if(w <= h) 
    glOrtho(-2.0,2.0,-2.0*(GLfloat)h/(GLfloat)w,2.0*(GLfloat)h/(GLfloat)w,-10.0,10.0);
    else 
    glOrtho(-2.0*(GLfloat)w/(GLfloat)h,2.0*(GLfloat)w/(GLfloat)h,-2.0,2.0,-10.0,10.0);
  glMatrixMode(GL_MODELVIEW);
}

void CALLBACK up(void) {
  anglex -= 2 ;
}

void CALLBACK down(void) {
  anglex += 2 ;
}

void CALLBACK left(void) {
  angley -= 2 ;
}

void CALLBACK right(void) {
  angley += 2 ;
}

void main(void) {
  auxInitDisplayMode(AUX_DOUBLE|AUX_RGB|AUX_DEPTH);
  auxInitPosition(0,0,200,300);
  auxInitWindow("Un teapot clippé");
  myinit();
  auxKeyFunc(AUX_UP,up) ;
  auxKeyFunc(AUX_DOWN,down) ;
  auxKeyFunc(AUX_LEFT,left) ;
  auxKeyFunc(AUX_RIGHT,right) ;
  auxReshapeFunc(myReshape);
  auxMainLoop(display);
}