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31 * Unpublished-- rights reserved under the copyright laws of the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 *  aapoly.c
40 *  This program draws filled polygons with antialiased
41 *  edges.  The special GL_SRC_ALPHA_SATURATE blending
42 *  function is used.
43 *  Pressing the 't' key turns the antialiasing on and off.
44 */
45#include "glut_wrap.h"
46#include <stdlib.h>
47#include <stdio.h>
48
49GLboolean polySmooth = GL_TRUE;
50
51static void init(void)
52{
53   glCullFace (GL_BACK);
54   glEnable (GL_CULL_FACE);
55   glBlendFunc (GL_SRC_ALPHA_SATURATE, GL_ONE);
56   glClearColor (0.0, 0.0, 0.0, 0.0);
57}
58
59#define NFACE 6
60#define NVERT 8
61static void drawCube(GLdouble x0, GLdouble x1, GLdouble y0, GLdouble y1,
62        GLdouble z0, GLdouble z1)
63{
64   static GLfloat v[8][3];
65   static GLfloat c[8][4] = {
66      {0.0, 0.0, 0.0, 1.0}, {1.0, 0.0, 0.0, 1.0},
67      {0.0, 1.0, 0.0, 1.0}, {1.0, 1.0, 0.0, 1.0},
68      {0.0, 0.0, 1.0, 1.0}, {1.0, 0.0, 1.0, 1.0},
69      {0.0, 1.0, 1.0, 1.0}, {1.0, 1.0, 1.0, 1.0}
70   };
71
72/*  indices of front, top, left, bottom, right, back faces  */
73   static GLubyte indices[NFACE][4] = {
74      {4, 5, 6, 7}, {2, 3, 7, 6}, {0, 4, 7, 3},
75      {0, 1, 5, 4}, {1, 5, 6, 2}, {0, 3, 2, 1}
76   };
77
78   v[0][0] = v[3][0] = v[4][0] = v[7][0] = x0;
79   v[1][0] = v[2][0] = v[5][0] = v[6][0] = x1;
80   v[0][1] = v[1][1] = v[4][1] = v[5][1] = y0;
81   v[2][1] = v[3][1] = v[6][1] = v[7][1] = y1;
82   v[0][2] = v[1][2] = v[2][2] = v[3][2] = z0;
83   v[4][2] = v[5][2] = v[6][2] = v[7][2] = z1;
84
85#ifdef GL_VERSION_1_1
86   glEnableClientState (GL_VERTEX_ARRAY);
87   glEnableClientState (GL_COLOR_ARRAY);
88   glVertexPointer (3, GL_FLOAT, 0, v);
89   glColorPointer (4, GL_FLOAT, 0, c);
90   glDrawElements (GL_QUADS, NFACE*4, GL_UNSIGNED_BYTE, indices);
91   glDisableClientState (GL_VERTEX_ARRAY);
92   glDisableClientState (GL_COLOR_ARRAY);
93#else
94   printf ("If this is GL Version 1.0, ");
95   printf ("vertex arrays are not supported.\n");
96   exit(1);
97#endif
98}
99
100/*  Note:  polygons must be drawn from front to back
101 *  for proper blending.
102 */
103static void display(void)
104{
105   if (polySmooth) {
106      glClear (GL_COLOR_BUFFER_BIT);
107      glEnable (GL_BLEND);
108      glEnable (GL_POLYGON_SMOOTH);
109      glDisable (GL_DEPTH_TEST);
110   }
111   else {
112      glClear (GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
113      glDisable (GL_BLEND);
114      glDisable (GL_POLYGON_SMOOTH);
115      glEnable (GL_DEPTH_TEST);
116   }
117
118   glPushMatrix ();
119      glTranslatef (0.0, 0.0, -8.0);
120      glRotatef (30.0, 1.0, 0.0, 0.0);
121      glRotatef (60.0, 0.0, 1.0, 0.0);
122      drawCube(-0.5, 0.5, -0.5, 0.5, -0.5, 0.5);
123   glPopMatrix ();
124
125   glFlush ();
126}
127
128static void reshape(int w, int h)
129{
130   glViewport(0, 0, (GLsizei) w, (GLsizei) h);
131   glMatrixMode(GL_PROJECTION);
132   glLoadIdentity();
133   gluPerspective(30.0, (GLfloat) w/(GLfloat) h, 1.0, 20.0);
134   glMatrixMode(GL_MODELVIEW);
135   glLoadIdentity();
136}
137
138/* ARGSUSED1 */
139static void keyboard(unsigned char key, int x, int y)
140{
141   switch (key) {
142      case 't':
143      case 'T':
144         polySmooth = !polySmooth;
145         glutPostRedisplay();
146         break;
147      case 27:
148         exit(0);  /*  Escape key  */
149         break;
150      default:
151         break;
152   }
153}
154
155/*  Main Loop
156 */
157int main(int argc, char** argv)
158{
159   glutInit(&argc, argv);
160   glutInitDisplayMode (GLUT_SINGLE | GLUT_RGB
161                        | GLUT_ALPHA | GLUT_DEPTH);
162   glutInitWindowSize(200, 200);
163   glutCreateWindow(argv[0]);
164   init ();
165   glutReshapeFunc (reshape);
166   glutKeyboardFunc (keyboard);
167   glutDisplayFunc (display);
168   glutMainLoop();
169   return 0;
170}
171
172