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Diffstat (limited to 'progs/redbook/feedback.c')
| -rw-r--r-- | progs/redbook/feedback.c | 171 |
1 files changed, 171 insertions, 0 deletions
diff --git a/progs/redbook/feedback.c b/progs/redbook/feedback.c new file mode 100644 index 00000000000..4981854d95d --- /dev/null +++ b/progs/redbook/feedback.c @@ -0,0 +1,171 @@ +/* + * 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 + * Unpublished-- rights reserved under the copyright laws of the + * United States.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. + */ + +/* + * feedback.c + * This program demonstrates use of OpenGL feedback. First, + * a lighting environment is set up and a few lines are drawn. + * Then feedback mode is entered, and the same lines are + * drawn. The results in the feedback buffer are printed. + */ +#include <GL/glut.h> +#include <stdlib.h> +#include <stdio.h> + +/* Initialize lighting. + */ +void init(void) +{ + glEnable(GL_LIGHTING); + glEnable(GL_LIGHT0); +} + +/* Draw a few lines and two points, one of which will + * be clipped. If in feedback mode, a passthrough token + * is issued between the each primitive. + */ +void drawGeometry (GLenum mode) +{ + glBegin (GL_LINE_STRIP); + glNormal3f (0.0, 0.0, 1.0); + glVertex3f (30.0, 30.0, 0.0); + glVertex3f (50.0, 60.0, 0.0); + glVertex3f (70.0, 40.0, 0.0); + glEnd (); + if (mode == GL_FEEDBACK) + glPassThrough (1.0); + glBegin (GL_POINTS); + glVertex3f (-100.0, -100.0, -100.0); /* will be clipped */ + glEnd (); + if (mode == GL_FEEDBACK) + glPassThrough (2.0); + glBegin (GL_POINTS); + glNormal3f (0.0, 0.0, 1.0); + glVertex3f (50.0, 50.0, 0.0); + glEnd (); +} + +/* Write contents of one vertex to stdout. */ +void print3DcolorVertex (GLint size, GLint *count, + GLfloat *buffer) +{ + int i; + + printf (" "); + for (i = 0; i < 7; i++) { + printf ("%4.2f ", buffer[size-(*count)]); + *count = *count - 1; + } + printf ("\n"); +} + +/* Write contents of entire buffer. (Parse tokens!) */ +void printBuffer(GLint size, GLfloat *buffer) +{ + GLint count; + GLfloat token; + + count = size; + while (count) { + token = buffer[size-count]; count--; + if (token == GL_PASS_THROUGH_TOKEN) { + printf ("GL_PASS_THROUGH_TOKEN\n"); + printf (" %4.2f\n", buffer[size-count]); + count--; + } + else if (token == GL_POINT_TOKEN) { + printf ("GL_POINT_TOKEN\n"); + print3DcolorVertex (size, &count, buffer); + } + else if (token == GL_LINE_TOKEN) { + printf ("GL_LINE_TOKEN\n"); + print3DcolorVertex (size, &count, buffer); + print3DcolorVertex (size, &count, buffer); + } + else if (token == GL_LINE_RESET_TOKEN) { + printf ("GL_LINE_RESET_TOKEN\n"); + print3DcolorVertex (size, &count, buffer); + print3DcolorVertex (size, &count, buffer); + } + } +} + +void display(void) +{ + GLfloat feedBuffer[1024]; + GLint size; + + glMatrixMode (GL_PROJECTION); + glLoadIdentity (); + glOrtho (0.0, 100.0, 0.0, 100.0, 0.0, 1.0); + + glClearColor (0.0, 0.0, 0.0, 0.0); + glClear(GL_COLOR_BUFFER_BIT); + drawGeometry (GL_RENDER); + + glFeedbackBuffer (1024, GL_3D_COLOR, feedBuffer); + (void) glRenderMode (GL_FEEDBACK); + drawGeometry (GL_FEEDBACK); + + size = glRenderMode (GL_RENDER); + printBuffer (size, feedBuffer); +} + +/* ARGSUSED1 */ +void keyboard(unsigned char key, int x, int y) +{ + switch (key) { + case 27: + exit(0); + break; + } +} + +/* Main Loop */ +int main(int argc, char** argv) +{ + glutInit(&argc, argv); + glutInitDisplayMode(GLUT_SINGLE | GLUT_RGB); + glutInitWindowSize (100, 100); + glutInitWindowPosition (100, 100); + glutCreateWindow(argv[0]); + init(); + glutDisplayFunc(display); + glutKeyboardFunc (keyboard); + glutMainLoop(); + return 0; +} |