progs/redbook/smooth.c

   1 /*
   2  * Copyright (c) 1993-1997, Silicon Graphics, Inc.
   3  * ALL RIGHTS RESERVED
   4  * Permission to use, copy, modify, and distribute this software for
   5  * any purpose and without fee is hereby granted, provided that the above
   6  * copyright notice appear in all copies and that both the copyright notice
   7  * and this permission notice appear in supporting documentation, and that
   8  * the name of Silicon Graphics, Inc. not be used in advertising
   9  * or publicity pertaining to distribution of the software without specific,
  10  * written prior permission.
  11  *
  12  * THE MATERIAL EMBODIED ON THIS SOFTWARE IS PROVIDED TO YOU "AS-IS"
  13  * AND WITHOUT WARRANTY OF ANY KIND, EXPRESS, IMPLIED OR OTHERWISE,
  14  * INCLUDING WITHOUT LIMITATION, ANY WARRANTY OF MERCHANTABILITY OR
  15  * FITNESS FOR A PARTICULAR PURPOSE.  IN NO EVENT SHALL SILICON
  16  * GRAPHICS, INC.  BE LIABLE TO YOU OR ANYONE ELSE FOR ANY DIRECT,
  17  * SPECIAL, INCIDENTAL, INDIRECT OR CONSEQUENTIAL DAMAGES OF ANY
  18  * KIND, OR ANY DAMAGES WHATSOEVER, INCLUDING WITHOUT LIMITATION,
  19  * LOSS OF PROFIT, LOSS OF USE, SAVINGS OR REVENUE, OR THE CLAIMS OF
  20  * THIRD PARTIES, WHETHER OR NOT SILICON GRAPHICS, INC.  HAS BEEN
  21  * ADVISED OF THE POSSIBILITY OF SUCH LOSS, HOWEVER CAUSED AND ON
  22  * ANY THEORY OF LIABILITY, ARISING OUT OF OR IN CONNECTION WITH THE
  23  * POSSESSION, USE OR PERFORMANCE OF THIS SOFTWARE.
  24  *
  25  * US Government Users Restricted Rights
  26  * Use, duplication, or disclosure by the Government is subject to
  27  * restrictions set forth in FAR 52.227.19(c)(2) or subparagraph
  28  * (c)(1)(ii) of the Rights in Technical Data and Computer Software
  29  * clause at DFARS 252.227-7013 and/or in similar or successor
  30  * clauses in the FAR or the DOD or NASA FAR Supplement.
  31  * Unpublished-- rights reserved under the copyright laws of the
  32  * United States.  Contractor/manufacturer is Silicon Graphics,
  33  * Inc., 2011 N.  Shoreline Blvd., Mountain View, CA 94039-7311.
  34  *
  35  * OpenGL(R) is a registered trademark of Silicon Graphics, Inc.
  36  */
  37
  38 /*
  39  * smooth.c
  40  * This program demonstrates smooth shading.
  41  * A smooth shaded polygon is drawn in a 2-D projection.
  42  */
  43 #include <GL/glut.h>
  44 #include <stdlib.h>
  45
  46 static void init(void)
  47 {
  48    glClearColor (0.0, 0.0, 0.0, 0.0);
  49    glShadeModel (GL_SMOOTH);
  50 }
  51
  52 static void triangle(void)
  53 {
  54    glBegin (GL_TRIANGLES);
  55    glColor3f (1.0, 0.0, 0.0);
  56    glVertex2f (5.0, 5.0);
  57    glColor3f (0.0, 1.0, 0.0);
  58    glVertex2f (25.0, 5.0);
  59    glColor3f (0.0, 0.0, 1.0);
  60    glVertex2f (5.0, 25.0);
  61    glEnd();
  62 }
  63
  64 static void display(void)
  65 {
  66    glClear (GL_COLOR_BUFFER_BIT);
  67    triangle ();
  68    glFlush ();
  69 }
  70
  71 static void reshape (int w, int h)
  72 {
  73    glViewport (0, 0, (GLsizei) w, (GLsizei) h);
  74    glMatrixMode (GL_PROJECTION);
  75    glLoadIdentity ();
  76    if (w <= h)
  77       gluOrtho2D (0.0, 30.0, 0.0, 30.0 * (GLfloat) h/(GLfloat) w);
  78    else
  79       gluOrtho2D (0.0, 30.0 * (GLfloat) w/(GLfloat) h, 0.0, 30.0);
  80    glMatrixMode(GL_MODELVIEW);
  81 }
  82
  83 /* ARGSUSED1 */
  84 static void keyboard(unsigned char key, int x, int y)
  85 {
  86    switch (key) {
  87       case 27:
  88          exit(0);
  89          break;
  90    }
  91 }
  92
  93 int main(int argc, char** argv)
  94 {
  95    glutInit(&argc, argv);
  96    glutInitDisplayMode (GLUT_SINGLE | GLUT_RGB);
  97    glutInitWindowSize (500, 500);
  98    glutInitWindowPosition (100, 100);
  99    glutCreateWindow (argv[0]);
 100    init ();
 101    glutDisplayFunc(display);
 102    glutReshapeFunc(reshape);
 103    glutKeyboardFunc (keyboard);
 104    glutMainLoop();
 105    return 0;
 106 }