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* Unpublished-- rights reserved under the copyright laws of the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