1/*
2 * Copyright (c) 1991, 1992, 1993 Silicon Graphics, Inc.
3 *
4 * Permission to use, copy, modify, distribute, and sell this software and
5 * its documentation for any purpose is hereby granted without fee, provided
6 * that (i) the above copyright notices and this permission notice appear in
7 * all copies of the software and related documentation, and (ii) the name of
8 * Silicon Graphics may not be used in any advertising or
9 * publicity relating to the software without the specific, prior written
10 * permission of Silicon Graphics.
11 *
12 * THE SOFTWARE IS PROVIDED "AS-IS" AND WITHOUT WARRANTY OF
13 * ANY KIND,
14 * EXPRESS, IMPLIED OR OTHERWISE, INCLUDING WITHOUT LIMITATION, ANY
15 * WARRANTY OF MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE.
16 *
17 * IN NO EVENT SHALL SILICON GRAPHICS BE LIABLE FOR
18 * ANY SPECIAL, INCIDENTAL, INDIRECT OR CONSEQUENTIAL DAMAGES OF ANY KIND,
19 * OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS,
20 * WHETHER OR NOT ADVISED OF THE POSSIBILITY OF DAMAGE, AND ON ANY THEORY OF
21 * LIABILITY, ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE
22 * OF THIS SOFTWARE.
23 */
24
25#include <stdio.h>
26#include <string.h>
27#include <stdlib.h>
28#include <GL/glew.h>
29#include "glut_wrap.h"
30
31
32
33#define CI_OFFSET_1 16
34#define CI_OFFSET_2 32
35
36static GLuint OccQuery;
37
38GLenum doubleBuffer;
39
40static void Init(void)
41{
42   if (!glutExtensionSupported("GL_ARB_occlusion_query")) {
43      fprintf(stderr, "Sorry, this program requires GL_ARB_occlusion_query\n");
44      exit(1);
45   }
46
47   fprintf(stderr, "GL_RENDERER   = %s\n", (char *) glGetString(GL_RENDERER));
48   fprintf(stderr, "GL_VERSION    = %s\n", (char *) glGetString(GL_VERSION));
49   fprintf(stderr, "GL_VENDOR     = %s\n", (char *) glGetString(GL_VENDOR));
50   fflush(stderr);
51
52    glClearColor(0.0, 0.0, 1.0, 0.0);
53
54   glGenQueriesARB(1, &OccQuery);
55}
56
57static void Reshape(int width, int height)
58{
59
60    glViewport(0, 0, (GLint)width, (GLint)height);
61
62    glMatrixMode(GL_PROJECTION);
63    glLoadIdentity();
64    glOrtho(-1.0, 1.0, -1.0, 1.0, -0.5, 1000.0);
65    glMatrixMode(GL_MODELVIEW);
66}
67
68static void Key(unsigned char key, int x, int y)
69{
70
71    switch (key) {
72      case 27:
73	exit(1);
74      default:
75	break;
76    }
77
78    glutPostRedisplay();
79}
80
81static void Draw(void)
82{
83   GLuint passed;
84   GLint ready;
85
86   glClear(GL_COLOR_BUFFER_BIT|GL_DEPTH_BUFFER_BIT);
87
88   glEnable(GL_DEPTH_TEST);
89
90   glBeginQueryARB(GL_SAMPLES_PASSED_ARB, OccQuery);
91
92   glBegin(GL_TRIANGLES);
93   glColor3f(0,0,.7);
94   glVertex3f( 0.9, -0.9, -30.0);
95   glColor3f(.8,0,0);
96   glVertex3f( 0.9,  0.9, -30.0);
97   glColor3f(0,.9,0);
98   glVertex3f(-0.9,  0.0, -30.0);
99   glEnd();
100
101   glEndQueryARB(GL_SAMPLES_PASSED_ARB);
102
103   do {
104      /* do useful work here, if any */
105      glGetQueryObjectivARB(OccQuery, GL_QUERY_RESULT_AVAILABLE_ARB, &ready);
106   } while (!ready);
107   glGetQueryObjectuivARB(OccQuery, GL_QUERY_RESULT_ARB, &passed);
108
109   fprintf(stderr, " %d Fragments Visible\n", passed);
110
111   glFlush();
112
113   if (doubleBuffer) {
114      glutSwapBuffers();
115   }
116}
117
118static GLenum Args(int argc, char **argv)
119{
120    GLint i;
121
122    doubleBuffer = GL_FALSE;
123
124    for (i = 1; i < argc; i++) {
125        if (strcmp(argv[i], "-sb") == 0) {
126	    doubleBuffer = GL_FALSE;
127	} else if (strcmp(argv[i], "-db") == 0) {
128	    doubleBuffer = GL_TRUE;
129	} else {
130	    fprintf(stderr, "%s (Bad option).\n", argv[i]);
131	    return GL_FALSE;
132	}
133    }
134    return GL_TRUE;
135}
136
137int main(int argc, char **argv)
138{
139    GLenum type;
140
141    glutInit(&argc, argv);
142
143    if (Args(argc, argv) == GL_FALSE) {
144	exit(1);
145    }
146
147    glutInitWindowPosition(100, 0); glutInitWindowSize( 250, 250);
148
149    type = GLUT_RGB | GLUT_DEPTH;
150    type |= (doubleBuffer) ? GLUT_DOUBLE : GLUT_SINGLE;
151    glutInitDisplayMode(type);
152
153    if (glutCreateWindow(*argv) == GL_FALSE) {
154	exit(1);
155    }
156
157    glewInit();
158
159    Init();
160
161    glutReshapeFunc(Reshape);
162    glutKeyboardFunc(Key);
163    glutDisplayFunc(Draw);
164    glutMainLoop();
165	return 0;
166}
167