1
2 /* Copyright (c) Mark J. Kilgard, 1994. */
3
4 /*
5 * (c) Copyright 1993, Silicon Graphics, Inc.
6 * ALL RIGHTS RESERVED
7 * Permission to use, copy, modify, and distribute this software for
8 * any purpose and without fee is hereby granted, provided that the above
9 * copyright notice appear in all copies and that both the copyright notice
10 * and this permission notice appear in supporting documentation, and that
11 * the name of Silicon Graphics, Inc. not be used in advertising
12 * or publicity pertaining to distribution of the software without specific,
13 * written prior permission.
14 *
15 * THE MATERIAL EMBODIED ON THIS SOFTWARE IS PROVIDED TO YOU "AS-IS"
16 * AND WITHOUT WARRANTY OF ANY KIND, EXPRESS, IMPLIED OR OTHERWISE,
17 * INCLUDING WITHOUT LIMITATION, ANY WARRANTY OF MERCHANTABILITY OR
18 * FITNESS FOR A PARTICULAR PURPOSE. IN NO EVENT SHALL SILICON
19 * GRAPHICS, INC. BE LIABLE TO YOU OR ANYONE ELSE FOR ANY DIRECT,
20 * SPECIAL, INCIDENTAL, INDIRECT OR CONSEQUENTIAL DAMAGES OF ANY
21 * KIND, OR ANY DAMAGES WHATSOEVER, INCLUDING WITHOUT LIMITATION,
22 * LOSS OF PROFIT, LOSS OF USE, SAVINGS OR REVENUE, OR THE CLAIMS OF
23 * THIRD PARTIES, WHETHER OR NOT SILICON GRAPHICS, INC. HAS BEEN
24 * ADVISED OF THE POSSIBILITY OF SUCH LOSS, HOWEVER CAUSED AND ON
25 * ANY THEORY OF LIABILITY, ARISING OUT OF OR IN CONNECTION WITH THE
26 * POSSESSION, USE OR PERFORMANCE OF THIS SOFTWARE.
27 *
28 * US Government Users Restricted Rights
29 * Use, duplication, or disclosure by the Government is subject to
30 * restrictions set forth in FAR 52.227.19(c)(2) or subparagraph
31 * (c)(1)(ii) of the Rights in Technical Data and Computer Software
32 * clause at DFARS 252.227-7013 and/or in similar or successor
33 * clauses in the FAR or the DOD or NASA FAR Supplement.
34 * Unpublished-- rights reserved under the copyright laws of the
35 * United States. Contractor/manufacturer is Silicon Graphics,
36 * Inc., 2011 N. Shoreline Blvd., Mountain View, CA 94039-7311.
37 *
38 * OpenGL(TM) is a trademark of Silicon Graphics, Inc.
39 */
40 /*
41 * anti.c
42 * This program draws antialiased lines in RGBA mode.
43 */
44 #include <stdlib.h>
45 #include <stdio.h>
46 #include "glut_wrap.h"
47
48 /* Initialize antialiasing for RGBA mode, including alpha
49 * blending, hint, and line width. Print out implementation
50 * specific info on line width granularity and width.
51 */
myinit(void)52 static void myinit(void)
53 {
54 GLfloat values[2];
55 glGetFloatv (GL_LINE_WIDTH_GRANULARITY, values);
56 printf ("GL_LINE_WIDTH_GRANULARITY value is %3.1f\n", values[0]);
57
58 glGetFloatv (GL_LINE_WIDTH_RANGE, values);
59 printf ("GL_LINE_WIDTH_RANGE values are %3.1f %3.1f\n",
60 values[0], values[1]);
61
62 glEnable (GL_LINE_SMOOTH);
63 glEnable (GL_BLEND);
64 glBlendFunc (GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA);
65 glHint (GL_LINE_SMOOTH_HINT, GL_DONT_CARE);
66 glLineWidth (1.5);
67
68 glShadeModel(GL_FLAT);
69 glClearColor(0.0, 0.0, 0.0, 0.0);
70 glDepthFunc(GL_LESS);
71 glEnable(GL_DEPTH_TEST);
72 }
73
74 /* display() draws an icosahedron with a large alpha value, 1.0.
75 */
display(void)76 static void display(void)
77 {
78 glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
79 glColor4f (1.0, 1.0, 1.0, 1.0);
80 glutWireIcosahedron();
81 glFlush();
82 }
83
myReshape(int w,int h)84 static void myReshape(int w, int h)
85 {
86 glViewport(0, 0, w, h);
87 glMatrixMode(GL_PROJECTION);
88 glLoadIdentity();
89 gluPerspective (45.0, (GLfloat) w/(GLfloat) h, 3.0, 5.0);
90
91 glMatrixMode(GL_MODELVIEW);
92 glLoadIdentity ();
93 glTranslatef (0.0, 0.0, -4.0); /* move object into view */
94 }
95
96 static void
key(unsigned char k,int x,int y)97 key(unsigned char k, int x, int y)
98 {
99 switch (k) {
100 case 27: /* Escape */
101 exit(0);
102 break;
103 default:
104 return;
105 }
106 glutPostRedisplay();
107 }
108
109 /* Main Loop
110 * Open window with initial window size, title bar,
111 * RGBA display mode, and handle input events.
112 */
main(int argc,char ** argv)113 int main(int argc, char** argv)
114 {
115 glutInit(&argc, argv);
116 glutInitDisplayMode (GLUT_SINGLE | GLUT_RGB | GLUT_DEPTH);
117 glutCreateWindow (argv[0]);
118 myinit();
119 glutReshapeFunc (myReshape);
120 glutDisplayFunc(display);
121 glutKeyboardFunc(key);
122 glutMainLoop();
123 return 0; /* ANSI C requires main to return int. */
124 }
125