1/*
2 * Copyright (c) 1993-2003, Silicon Graphics, Inc.
3 * All Rights Reserved
4 *
5 * Permission to use, copy, modify, and distribute this software for any
6 * purpose and without fee is hereby granted, provided that the above
7 * copyright notice appear in all copies and that both the copyright
8 * notice and this permission notice appear in supporting documentation,
9 * and that the name of Silicon Graphics, Inc. not be used in
10 * advertising or publicity pertaining to distribution of the software
11 * without specific, written prior permission.
12 *
13 * THE MATERIAL EMBODIED ON THIS SOFTWARE IS PROVIDED TO YOU "AS-IS" AND
14 * WITHOUT WARRANTY OF ANY KIND, EXPRESS, IMPLIED OR OTHERWISE,
15 * INCLUDING WITHOUT LIMITATION, ANY WARRANTY OF MERCHANTABILITY OR
16 * FITNESS FOR A PARTICULAR PURPOSE.  IN NO EVENT SHALL SILICON
17 * GRAPHICS, INC.  BE LIABLE TO YOU OR ANYONE ELSE FOR ANY DIRECT,
18 * SPECIAL, INCIDENTAL, INDIRECT OR CONSEQUENTIAL DAMAGES OF ANY KIND,
19 * OR ANY DAMAGES WHATSOEVER, INCLUDING WITHOUT LIMITATION, LOSS OF
20 * PROFIT, LOSS OF USE, SAVINGS OR REVENUE, OR THE CLAIMS OF THIRD
21 * PARTIES, WHETHER OR NOT SILICON GRAPHICS, INC.  HAS BEEN ADVISED OF
22 * THE POSSIBILITY OF SUCH LOSS, HOWEVER CAUSED AND ON ANY THEORY OF
23 * LIABILITY, ARISING OUT OF OR IN CONNECTION WITH THE POSSESSION, USE
24 * OR PERFORMANCE OF THIS SOFTWARE.
25 *
26 * US Government Users Restricted Rights
27 * Use, duplication, or disclosure by the Government is subject to
28 * restrictions set forth in FAR 52.227.19(c)(2) or subparagraph
29 * (c)(1)(ii) of the Rights in Technical Data and Computer Software
30 * clause at DFARS 252.227-7013 and/or in similar or successor clauses
31 * in the FAR or the DOD or NASA FAR Supplement.  Unpublished - rights
32 * reserved under the copyright laws of the United States.
33 *
34 * Contractor/manufacturer is:
35 *	Silicon Graphics, Inc.
36 *	1500 Crittenden Lane
37 *	Mountain View, CA  94043
38 *	United State of America
39 *
40 * OpenGL(R) is a registered trademark of Silicon Graphics, Inc.
41 */
42
43/*
44 *  multisamp.c
45 *  This program draws shows how to use multisampling to
46 *  draw anti-aliased geometric primitives.  The same
47 *  display list, a pinwheel of triangles and lines of
48 *  varying widths, is rendered twice.  Multisampling is
49 *  enabled when the left side is drawn.  Multisampling is
50 *  disabled when the right side is drawn.
51 *
52 *  Pressing the 'b' key toggles drawing of the checkerboard
53 *  background.  Antialiasing is sometimes easier to see
54 *  when objects are rendered over a contrasting background.
55 */
56#include <GL/glew.h>
57#include "glut_wrap.h"
58#include <stdlib.h>
59#include <stdio.h>
60
61static int bgtoggle = 1;
62
63/*
64 *  Print out state values related to multisampling.
65 *  Create display list with "pinwheel" of lines and
66 *  triangles.
67 */
68static void init(void)
69{
70   static GLint buf[1], sbuf[1];
71   int i, j;
72
73   glClearColor(0.0, 0.0, 0.0, 0.0);
74   glGetIntegerv (GL_SAMPLE_BUFFERS_ARB, buf);
75   printf ("number of sample buffers is %d\n", buf[0]);
76   glGetIntegerv (GL_SAMPLES_ARB, sbuf);
77   printf ("number of samples is %d\n", sbuf[0]);
78
79   glNewList (1, GL_COMPILE);
80   for (i = 0; i < 19; i++) {
81      glPushMatrix();
82      glRotatef(360.0*(float)i/19.0, 0.0, 0.0, 1.0);
83      glColor3f (1.0, 1.0, 1.0);
84      glLineWidth((i%3)+1.0);
85      glBegin (GL_LINES);
86         glVertex2f (0.25, 0.05);
87         glVertex2f (0.9, 0.2);
88      glEnd ();
89      glColor3f (0.0, 1.0, 1.0);
90      glBegin (GL_TRIANGLES);
91         glVertex2f (0.25, 0.0);
92         glVertex2f (0.9, 0.0);
93         glVertex2f (0.875, 0.10);
94      glEnd ();
95      glPopMatrix();
96   }
97   glEndList ();
98
99   glNewList (2, GL_COMPILE);
100   glColor3f (1.0, 0.5, 0.0);
101   glBegin (GL_QUADS);
102   for (i = 0; i < 16; i++) {
103      for (j = 0; j < 16; j++) {
104         if (((i + j) % 2) == 0) {
105            glVertex2f (-2.0 + (i * 0.25), -2.0 + (j * 0.25));
106            glVertex2f (-2.0 + (i * 0.25), -1.75 + (j * 0.25));
107            glVertex2f (-1.75 + (i * 0.25), -1.75 + (j * 0.25));
108            glVertex2f (-1.75 + (i * 0.25), -2.0 + (j * 0.25));
109         }
110      }
111   }
112   glEnd ();
113   glEndList ();
114}
115
116/*  Draw two sets of primitives, so that you can
117 *  compare the user of multisampling against its absence.
118 *
119 *  This code enables antialiasing and draws one display list
120 *  and disables and draws the other display list
121 */
122static void display(void)
123{
124   glClear(GL_COLOR_BUFFER_BIT);
125
126   if (bgtoggle)
127      glCallList (2);
128
129   glEnable (GL_MULTISAMPLE_ARB);
130   glPushMatrix();
131   glTranslatef (-1.0, 0.0, 0.0);
132   glCallList (1);
133   glPopMatrix();
134
135   glDisable (GL_MULTISAMPLE_ARB);
136   glPushMatrix();
137   glTranslatef (1.0, 0.0, 0.0);
138   glCallList (1);
139   glPopMatrix();
140   glutSwapBuffers();
141}
142
143static void reshape(int w, int h)
144{
145   glViewport(0, 0, w, h);
146   glMatrixMode(GL_PROJECTION);
147   glLoadIdentity();
148   if (w <= (2 * h))
149      gluOrtho2D (-2.0, 2.0,
150         -2.0*(GLfloat)h/(GLfloat)w, 2.0*(GLfloat)h/(GLfloat)w);
151   else
152      gluOrtho2D (-2.0*(GLfloat)w/(GLfloat)h,
153         2.0*(GLfloat)w/(GLfloat)h, -2.0, 2.0);
154   glMatrixMode(GL_MODELVIEW);
155   glLoadIdentity();
156}
157
158static void keyboard(unsigned char key, int x, int y)
159{
160   switch (key) {
161      case 'b':
162      case 'B':
163         bgtoggle = !bgtoggle;
164         glutPostRedisplay();
165         break;
166      case 27:  /*  Escape Key  */
167         exit(0);
168      default:
169         break;
170    }
171}
172
173/*  Main Loop
174 *  Open window with initial window size, title bar,
175 *  RGBA display mode, and handle input events.
176 */
177int main(int argc, char** argv)
178{
179   glutInit(&argc, argv);
180   glutInitDisplayMode (GLUT_DOUBLE | GLUT_RGB | GLUT_MULTISAMPLE);
181   glutInitWindowSize (600, 300);
182   glutCreateWindow (argv[0]);
183   init();
184   glutReshapeFunc (reshape);
185   glutKeyboardFunc (keyboard);
186   glutDisplayFunc (display);
187   glutMainLoop();
188   return 0;
189}
190