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 "glut_wrap.h"
29
30
31 GLint Width = 250, Height = 250;
32 GLenum doubleBuffer;
33 GLint Win;
34 GLboolean Rmask = GL_TRUE, Gmask = GL_FALSE, Bmask = GL_TRUE;
35
36
Init(void)37 static void Init(void)
38 {
39 fprintf(stderr, "GL_RENDERER = %s\n", (char *) glGetString(GL_RENDERER));
40 fprintf(stderr, "GL_VERSION = %s\n", (char *) glGetString(GL_VERSION));
41 fprintf(stderr, "GL_VENDOR = %s\n", (char *) glGetString(GL_VENDOR));
42 fflush(stderr);
43 glClearColor(0.0, 0.0, 1.0, 0.0);
44 }
45
Reshape(int width,int height)46 static void Reshape(int width, int height)
47 {
48 glViewport(0, 0, (GLint)width, (GLint)height);
49 glMatrixMode(GL_PROJECTION);
50 glLoadIdentity();
51 glOrtho(-1.0, 1.0, -1.0, 1.0, -0.5, 1000.0);
52 glMatrixMode(GL_MODELVIEW);
53 }
54
Key(unsigned char key,int x,int y)55 static void Key(unsigned char key, int x, int y)
56 {
57 switch (key) {
58 case 'r':
59 Rmask = !Rmask;
60 break;
61 case 'g':
62 Gmask = !Gmask;
63 break;
64 case 'b':
65 Bmask = !Bmask;
66 break;
67 case 27:
68 glutDestroyWindow(Win);
69 exit(1);
70 default:
71 return;
72 }
73 glutPostRedisplay();
74 }
75
Draw(void)76 static void Draw(void)
77 {
78 printf("ColorMask = %d, %d, %d\n", Rmask, Gmask, Bmask);
79 glColorMask(1,1,1,1);
80
81 glClear(GL_COLOR_BUFFER_BIT);
82
83 /* right triangle: green */
84 glBegin(GL_TRIANGLES);
85 glColor3f(0,1,0);
86 glVertex3f( 0.9, -0.9, -30.0);
87 glVertex3f( 0.9, 0.9, -30.0);
88 glVertex3f(-0.9, 0.0, -30.0);
89 glEnd();
90
91 glColorMask(Rmask, Gmask, Bmask, 0);
92
93 /* left triangle: white&mask: purple middle region: white */
94 glBegin(GL_TRIANGLES);
95 glColor3f(1,1,1);
96 glVertex3f(-0.9, -0.9, -30.0);
97 glVertex3f(-0.9, 0.9, -30.0);
98 glVertex3f( 0.9, 0.0, -30.0);
99 glEnd();
100
101 glDisable(GL_SCISSOR_TEST);
102
103 glFlush();
104
105 if (doubleBuffer) {
106 glutSwapBuffers();
107 }
108 }
109
Args(int argc,char ** argv)110 static GLenum Args(int argc, char **argv)
111 {
112 GLint i;
113
114 doubleBuffer = GL_FALSE;
115
116 for (i = 1; i < argc; i++) {
117 if (strcmp(argv[i], "-sb") == 0) {
118 doubleBuffer = GL_FALSE;
119 }
120 else if (strcmp(argv[i], "-db") == 0) {
121 doubleBuffer = GL_TRUE;
122 }
123 else {
124 fprintf(stderr, "%s (Bad option).\n", argv[i]);
125 return GL_FALSE;
126 }
127 }
128 return GL_TRUE;
129 }
130
131
main(int argc,char ** argv)132 int main(int argc, char **argv)
133 {
134 GLenum type;
135
136 glutInit(&argc, argv);
137
138 if (Args(argc, argv) == GL_FALSE) {
139 exit(1);
140 }
141
142 type = GLUT_RGB;
143 type |= (doubleBuffer) ? GLUT_DOUBLE : GLUT_SINGLE;
144
145 glutInitWindowPosition(100, 0); glutInitWindowSize(Width, Height);
146 glutInitDisplayMode(type);
147 Win = glutCreateWindow(*argv);
148 Init();
149 glutReshapeFunc(Reshape);
150 glutKeyboardFunc(Key);
151 glutDisplayFunc(Draw);
152 glutMainLoop();
153 return 0;
154 }
155