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Diffstat (limited to 'progs/redbook/image.c')
| -rw-r--r-- | progs/redbook/image.c | 159 |
1 files changed, 159 insertions, 0 deletions
diff --git a/progs/redbook/image.c b/progs/redbook/image.c new file mode 100644 index 00000000000..dc1a7246eba --- /dev/null +++ b/progs/redbook/image.c @@ -0,0 +1,159 @@ +/* + * 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 + * Unpublished-- rights reserved under the copyright laws of the + * United States.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; +} |