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 <stdlib.h>
27#include <string.h>
28#include <math.h>
29#include "glut_wrap.h"
30
31
32static void Init(void)
33{
34   glShadeModel(GL_FLAT);
35    glClearColor(0.0, 0.0, 0.0, 0.0);
36
37    glClearStencil(0);
38    glStencilMask(1);
39    glEnable(GL_STENCIL_TEST);
40}
41
42static void Reshape(int width, int height)
43{
44
45    glViewport(0, 0, (GLint)width, (GLint)height);
46
47    glMatrixMode(GL_PROJECTION);
48    glLoadIdentity();
49    glOrtho(-5.0, 5.0, -5.0, 5.0, -5.0, 5.0);
50    glMatrixMode(GL_MODELVIEW);
51}
52
53static void Key(unsigned char key, int x, int y)
54{
55
56    switch (key) {
57      case 27:
58	exit(1);
59    }
60}
61
62static void Draw(void)
63{
64
65    glClear(GL_COLOR_BUFFER_BIT|GL_STENCIL_BUFFER_BIT);
66
67    glStencilFunc(GL_ALWAYS, 1, 1);
68    glStencilOp(GL_KEEP, GL_KEEP, GL_REPLACE);
69
70    glColor3ub(200, 0, 0);
71    glBegin(GL_POLYGON);
72	glVertex3i(-4, -4, 0);
73	glVertex3i( 4, -4, 0);
74	glVertex3i( 0,  4, 0);
75    glEnd();
76
77    glStencilFunc(GL_EQUAL, 1, 1);
78    glStencilOp(GL_INCR, GL_KEEP, GL_DECR);
79
80    glColor3ub(0, 200, 0);
81    glBegin(GL_POLYGON);
82	glVertex3i(3, 3, 0);
83	glVertex3i(-3, 3, 0);
84	glVertex3i(-3, -3, 0);
85	glVertex3i(3, -3, 0);
86    glEnd();
87
88    glStencilFunc(GL_EQUAL, 1, 1);
89    glStencilOp(GL_KEEP, GL_KEEP, GL_KEEP);
90
91    glColor3ub(0, 0, 200);
92    glBegin(GL_POLYGON);
93	glVertex3i(3, 3, 0);
94	glVertex3i(-3, 3, 0);
95	glVertex3i(-3, -3, 0);
96	glVertex3i(3, -3, 0);
97    glEnd();
98
99    glFlush();
100}
101
102static GLenum Args(int argc, char **argv)
103{
104    GLint i;
105
106
107    for (i = 1; i < argc; i++) {
108	if (strcmp(argv[i], "-dr") == 0) {
109	} else {
110	    printf("%s (Bad option).\n", argv[i]);
111	    return GL_FALSE;
112	}
113    }
114    return GL_TRUE;
115}
116
117int main(int argc, char **argv)
118{
119    GLenum type;
120
121    glutInit(&argc, argv);
122
123    if (Args(argc, argv) == GL_FALSE) {
124	exit(1);
125    }
126
127    glutInitWindowPosition(0, 0); glutInitWindowSize( 300, 300);
128
129    type = GLUT_RGB | GLUT_SINGLE | GLUT_STENCIL;
130    glutInitDisplayMode(type);
131
132    if (glutCreateWindow("Stencil Test") == GL_FALSE) {
133	exit(1);
134    }
135
136    Init();
137
138    glutReshapeFunc(Reshape);
139    glutKeyboardFunc(Key);
140    glutDisplayFunc(Draw);
141    glutMainLoop();
142	return 0;
143}
144