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 = 300, Height = 300;
35
36GLenum doubleBuffer;
37
38/* scissor bounds */
39static GLint Left, Right, Bottom, Top;
40
41
42static void Init(void)
43{
44   fprintf(stderr, "GL_RENDERER   = %s\n", (char *) glGetString(GL_RENDERER));
45   fprintf(stderr, "GL_VERSION    = %s\n", (char *) glGetString(GL_VERSION));
46   fprintf(stderr, "GL_VENDOR     = %s\n", (char *) glGetString(GL_VENDOR));
47   fflush(stderr);
48
49    glClearColor(0.0, 0.0, 1.0, 0.0);
50}
51
52static void Reshape(int width, int height)
53{
54    glViewport(0, 0, (GLint)width, (GLint)height);
55
56    glMatrixMode(GL_PROJECTION);
57    glLoadIdentity();
58    glOrtho(-1.0, 1.0, -1.0, 1.0, -0.5, 1000.0);
59    glMatrixMode(GL_MODELVIEW);
60
61    Width = width;
62    Height = height;
63
64    Left = Width / 4;
65    Right = Width * 3 / 4;
66    Bottom = Height / 4;
67    Top = Height * 3 / 4;
68}
69
70static void Key(unsigned char key, int x, int y)
71{
72   int step = 2;
73   switch (key) {
74   case 'l':
75      Left -= step;
76      break;
77   case 'L':
78      Left += step;
79      break;
80   case 'r':
81      Right -= step;
82      break;
83   case 'R':
84      Right += step;
85      break;
86   case 'b':
87      Bottom -= step;
88      break;
89   case 'B':
90      Bottom += step;
91      break;
92   case 't':
93      Top -= step;
94      break;
95   case 'T':
96      Top += step;
97      break;
98   case 27:
99      exit(1);
100   default:
101      ;
102   }
103
104   glutPostRedisplay();
105}
106
107static void Draw(void)
108{
109   glClear(GL_COLOR_BUFFER_BIT);
110
111   glBegin(GL_TRIANGLES);
112   glColor3f(0,0,.7);
113   glVertex3f( 0.9, -0.9, -30.0);
114   glColor3f(.8,0,0);
115   glVertex3f( 0.9,  0.9, -30.0);
116   glColor3f(0,.9,0);
117   glVertex3f(-0.9,  0.0, -30.0);
118   glEnd();
119
120   printf("Scissor %d, %d .. %d, %d\n", Left, Bottom, Right, Top);
121   glScissor(Left, Bottom, Right-Left, Top-Bottom);
122   glEnable(GL_SCISSOR_TEST);
123
124   glBegin(GL_TRIANGLES);
125   glColor3f(0,0,.7);
126   glVertex3f(-0.9, -0.9, -30.0);
127   glColor3f(.8,0,0);
128   glVertex3f(-0.9,  0.9, -30.0);
129   glColor3f(0,.9,0);
130   glVertex3f( 0.9,  0.0, -30.0);
131   glEnd();
132
133   glDisable(GL_SCISSOR_TEST);
134
135   glFlush();
136
137   if (doubleBuffer) {
138      glutSwapBuffers();
139   }
140}
141
142static GLenum Args(int argc, char **argv)
143{
144    GLint i;
145
146    doubleBuffer = GL_FALSE;
147
148    for (i = 1; i < argc; i++) {
149        if (strcmp(argv[i], "-sb") == 0) {
150	    doubleBuffer = GL_FALSE;
151	} else if (strcmp(argv[i], "-db") == 0) {
152	    doubleBuffer = GL_TRUE;
153	} else {
154	    fprintf(stderr, "%s (Bad option).\n", argv[i]);
155	    return GL_FALSE;
156	}
157    }
158    return GL_TRUE;
159}
160
161int main(int argc, char **argv)
162{
163    GLenum type;
164
165    glutInit(&argc, argv);
166
167    if (Args(argc, argv) == GL_FALSE) {
168	exit(1);
169    }
170
171    glutInitWindowPosition(100, 0); glutInitWindowSize(Width, Height);
172
173    type = GLUT_RGB;
174    type |= (doubleBuffer) ? GLUT_DOUBLE : GLUT_SINGLE;
175    glutInitDisplayMode(type);
176
177    if (glutCreateWindow(*argv) == GL_FALSE) {
178	exit(1);
179    }
180
181    Init();
182
183    glutReshapeFunc(Reshape);
184    glutKeyboardFunc(Key);
185    glutDisplayFunc(Draw);
186    glutMainLoop();
187	return 0;
188}
189