1/*
2 * Copyright (c) 1993-1997, Silicon Graphics, Inc.
3 * ALL RIGHTS RESERVED
4 * Permission to use, copy, modify, and distribute this software for
5 * any purpose and without fee is hereby granted, provided that the above
6 * copyright notice appear in all copies and that both the copyright notice
7 * and this permission notice appear in supporting documentation, and that
8 * the name of Silicon Graphics, Inc. not be used in advertising
9 * or publicity pertaining to distribution of the software without specific,
10 * written prior permission.
11 *
12 * THE MATERIAL EMBODIED ON THIS SOFTWARE IS PROVIDED TO YOU "AS-IS"
13 * AND WITHOUT WARRANTY OF ANY KIND, EXPRESS, IMPLIED OR OTHERWISE,
14 * INCLUDING WITHOUT LIMITATION, ANY WARRANTY OF MERCHANTABILITY OR
15 * FITNESS FOR A PARTICULAR PURPOSE.  IN NO EVENT SHALL SILICON
16 * GRAPHICS, INC.  BE LIABLE TO YOU OR ANYONE ELSE FOR ANY DIRECT,
17 * SPECIAL, INCIDENTAL, INDIRECT OR CONSEQUENTIAL DAMAGES OF ANY
18 * KIND, OR ANY DAMAGES WHATSOEVER, INCLUDING WITHOUT LIMITATION,
19 * LOSS OF PROFIT, LOSS OF USE, SAVINGS OR REVENUE, OR THE CLAIMS OF
20 * THIRD PARTIES, WHETHER OR NOT SILICON GRAPHICS, INC.  HAS BEEN
21 * ADVISED OF THE POSSIBILITY OF SUCH LOSS, HOWEVER CAUSED AND ON
22 * ANY THEORY OF LIABILITY, ARISING OUT OF OR IN CONNECTION WITH THE
23 * POSSESSION, USE OR PERFORMANCE OF THIS SOFTWARE.
24 *
25 * US Government Users Restricted Rights
26 * Use, duplication, or disclosure by the Government is subject to
27 * restrictions set forth in FAR 52.227.19(c)(2) or subparagraph
28 * (c)(1)(ii) of the Rights in Technical Data and Computer Software
29 * clause at DFARS 252.227-7013 and/or in similar or successor
30 * clauses in the FAR or the DOD or NASA FAR Supplement.
31 * Unpublished-- rights reserved under the copyright laws of the
32 * United States.  Contractor/manufacturer is Silicon Graphics,
33 * Inc., 2011 N.  Shoreline Blvd., Mountain View, CA 94039-7311.
34 *
35 * OpenGL(R) is a registered trademark of Silicon Graphics, Inc.
36 */
37
38/*  image.c
39 *  This program demonstrates drawing pixels and shows the effect
40 *  of glDrawPixels(), glCopyPixels(), and glPixelZoom().
41 *  Interaction: moving the mouse while pressing the mouse button
42 *  will copy the image in the lower-left corner of the window
43 *  to the mouse position, using the current pixel zoom factors.
44 *  There is no attempt to prevent you from drawing over the original
45 *  image.  If you press the 'r' key, the original image and zoom
46 *  factors are reset.  If you press the 'z' or 'Z' keys, you change
47 *  the zoom factors.
48 */
49#include "glut_wrap.h"
50#include <stdlib.h>
51#include <stdio.h>
52
53/*	Create checkerboard image	*/
54#define	checkImageWidth 64
55#define	checkImageHeight 64
56GLubyte checkImage[checkImageHeight][checkImageWidth][3];
57
58static GLdouble zoomFactor = 1.0;
59static GLint height;
60
61static void makeCheckImage(void)
62{
63   int i, j, c;
64
65   for (i = 0; i < checkImageHeight; i++) {
66      for (j = 0; j < checkImageWidth; j++) {
67         c = (((i&0x8)==0)^((j&0x8)==0))*255;
68         checkImage[i][j][0] = (GLubyte) c;
69         checkImage[i][j][1] = (GLubyte) c;
70         checkImage[i][j][2] = (GLubyte) c;
71      }
72   }
73}
74
75static void init(void)
76{
77   glClearColor (0.0, 0.0, 0.0, 0.0);
78   glShadeModel(GL_FLAT);
79   makeCheckImage();
80   glPixelStorei(GL_UNPACK_ALIGNMENT, 1);
81}
82
83static void display(void)
84{
85   glClear(GL_COLOR_BUFFER_BIT);
86   glRasterPos2i(0, 0);
87   glDrawPixels(checkImageWidth, checkImageHeight, GL_RGB,
88                GL_UNSIGNED_BYTE, checkImage);
89   glFlush();
90}
91
92static void reshape(int w, int h)
93{
94   glViewport(0, 0, (GLsizei) w, (GLsizei) h);
95   height = (GLint) h;
96   glMatrixMode(GL_PROJECTION);
97   glLoadIdentity();
98   gluOrtho2D(0.0, (GLdouble) w, 0.0, (GLdouble) h);
99   glMatrixMode(GL_MODELVIEW);
100   glLoadIdentity();
101}
102
103static void motion(int x, int y)
104{
105   static GLint screeny;
106
107   screeny = height - (GLint) y;
108   glRasterPos2i (x, screeny);
109   glPixelZoom (zoomFactor, zoomFactor);
110   glCopyPixels (0, 0, checkImageWidth, checkImageHeight, GL_COLOR);
111   glPixelZoom (1.0, 1.0);
112   glFlush ();
113}
114
115/* ARGSUSED1 */
116static void keyboard(unsigned char key, int x, int y)
117{
118   switch (key) {
119      case 'r':
120      case 'R':
121         zoomFactor = 1.0;
122         glutPostRedisplay();
123         printf ("zoomFactor reset to 1.0\n");
124         break;
125      case 'z':
126         zoomFactor += 0.5;
127         if (zoomFactor >= 3.0)
128            zoomFactor = 3.0;
129         printf ("zoomFactor is now %4.1f\n", zoomFactor);
130         break;
131      case 'Z':
132         zoomFactor -= 0.5;
133         if (zoomFactor <= 0.5)
134            zoomFactor = 0.5;
135         printf ("zoomFactor is now %4.1f\n", zoomFactor);
136         break;
137      case 27:
138         exit(0);
139         break;
140      default:
141         break;
142   }
143}
144
145int main(int argc, char** argv)
146{
147   glutInit(&argc, argv);
148   glutInitDisplayMode(GLUT_SINGLE | GLUT_RGB);
149   glutInitWindowSize(250, 250);
150   glutInitWindowPosition(100, 100);
151   glutCreateWindow(argv[0]);
152   init();
153   glutDisplayFunc(display);
154   glutReshapeFunc(reshape);
155   glutKeyboardFunc(keyboard);
156   glutMotionFunc(motion);
157   glutMainLoop();
158   return 0;
159}
160