tri-clear.c revision 32001f49 
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#define CI_OFFSET_1 16
32#define CI_OFFSET_2 32
33
34GLint Width = 250, Height = 250;
35
36GLenum doubleBuffer;
37
38static void Init(void)
39{
40   fprintf(stderr, "GL_RENDERER   = %s\n", (char *) glGetString(GL_RENDERER));
41   fprintf(stderr, "GL_VERSION    = %s\n", (char *) glGetString(GL_VERSION));
42   fprintf(stderr, "GL_VENDOR     = %s\n", (char *) glGetString(GL_VENDOR));
43   fflush(stderr);
44
45}
46
47static void Reshape(int width, int height)
48{
49
50    glViewport(0, 0, (GLint)width, (GLint)height);
51
52    glMatrixMode(GL_PROJECTION);
53    glLoadIdentity();
54    glOrtho(-1.0, 1.0, -1.0, 1.0, -0.5, 1000.0);
55    glMatrixMode(GL_MODELVIEW);
56}
57
58static void Key(unsigned char key, int x, int y)
59{
60
61    switch (key) {
62      case 27:
63	exit(1);
64      default:
65	break;
66    }
67
68    glutPostRedisplay();
69}
70
71static void Draw(void)
72{
73   glClearColor(0.0, 0.0, 1.0, 1.0);
74   glClear(GL_COLOR_BUFFER_BIT);
75
76   glBegin(GL_TRIANGLES);
77   glColor3f(0,0,.7);
78   glVertex3f( 0.9, -0.9, -30.0);
79   glColor3f(.8,0,0);
80   glVertex3f( 0.9,  0.9, -30.0);
81   glColor3f(0,.9,0);
82   glVertex3f(-0.9,  0.0, -30.0);
83   glEnd();
84
85   glEnable(GL_SCISSOR_TEST);
86   glClearColor(1, 0, 1, 0);
87   glScissor(Width / 2, Height / 2, Width - Width / 2, Height - Height / 2);
88   glClear(GL_COLOR_BUFFER_BIT);
89   glDisable(GL_SCISSOR_TEST);
90
91   glFlush();
92
93   if (doubleBuffer) {
94      glutSwapBuffers();
95   }
96}
97
98static GLenum Args(int argc, char **argv)
99{
100    GLint i;
101
102    doubleBuffer = GL_FALSE;
103
104    for (i = 1; i < argc; i++) {
105        if (strcmp(argv[i], "-sb") == 0) {
106	    doubleBuffer = GL_FALSE;
107	} else if (strcmp(argv[i], "-db") == 0) {
108	    doubleBuffer = GL_TRUE;
109	} else {
110	    fprintf(stderr, "%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(100, 0); glutInitWindowSize( Width, Height);
128
129    type = GLUT_RGB;
130    type |= (doubleBuffer) ? GLUT_DOUBLE : GLUT_SINGLE;
131    glutInitDisplayMode(type);
132
133    if (glutCreateWindow(*argv) == GL_FALSE) {
134	exit(1);
135    }
136
137    Init();
138
139    glutReshapeFunc(Reshape);
140    glutKeyboardFunc(Key);
141    glutDisplayFunc(Draw);
142    glutMainLoop();
143	return 0;
144}
145