| /* |
| * 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| * Unpublished-- rights reserved under the copyright laws of the |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. |
| */ |
| |
| /* |
| * unproject.c |
| * When the left mouse button is pressed, this program |
| * reads the mouse position and determines two 3D points |
| * from which it was transformed. Very little is displayed. |
| */ |
| #include <GL/glut.h> |
| #include <stdlib.h> |
| #include <stdio.h> |
| |
| static void display(void) |
| { |
| glClear(GL_COLOR_BUFFER_BIT); |
| glFlush(); |
| } |
| |
| /* Change these values for a different transformation */ |
| static void reshape(int w, int h) |
| { |
| glViewport (0, 0, (GLsizei) w, (GLsizei) h); |
| glMatrixMode(GL_PROJECTION); |
| glLoadIdentity(); |
| gluPerspective (45.0, (GLfloat) w/(GLfloat) h, 1.0, 100.0); |
| glMatrixMode(GL_MODELVIEW); |
| glLoadIdentity(); |
| } |
| |
| static void mouse(int button, int state, int x, int y) |
| { |
| GLint viewport[4]; |
| GLdouble mvmatrix[16], projmatrix[16]; |
| GLint realy; /* OpenGL y coordinate position */ |
| GLdouble wx, wy, wz; /* returned world x, y, z coords */ |
| |
| switch (button) { |
| case GLUT_LEFT_BUTTON: |
| if (state == GLUT_DOWN) { |
| glGetIntegerv (GL_VIEWPORT, viewport); |
| glGetDoublev (GL_MODELVIEW_MATRIX, mvmatrix); |
| glGetDoublev (GL_PROJECTION_MATRIX, projmatrix); |
| /* note viewport[3] is height of window in pixels */ |
| realy = viewport[3] - (GLint) y - 1; |
| printf ("Coordinates at cursor are (%4d, %4d)\n", x, realy); |
| gluUnProject ((GLdouble) x, (GLdouble) realy, 0.0, |
| mvmatrix, projmatrix, viewport, &wx, &wy, &wz); |
| printf ("World coords at z=0.0 are (%f, %f, %f)\n", |
| wx, wy, wz); |
| gluUnProject ((GLdouble) x, (GLdouble) realy, 1.0, |
| mvmatrix, projmatrix, viewport, &wx, &wy, &wz); |
| printf ("World coords at z=1.0 are (%f, %f, %f)\n", |
| wx, wy, wz); |
| } |
| break; |
| case GLUT_RIGHT_BUTTON: |
| if (state == GLUT_DOWN) |
| exit(0); |
| break; |
| default: |
| break; |
| } |
| } |
| |
| /* ARGSUSED1 */ |
| static void keyboard(unsigned char key, int x, int y) |
| { |
| switch (key) { |
| case 27: |
| exit(0); |
| break; |
| } |
| } |
| |
| /* |
| * Open window, register input callback functions |
| */ |
| int main(int argc, char** argv) |
| { |
| glutInit(&argc, argv); |
| glutInitDisplayMode (GLUT_SINGLE | GLUT_RGB); |
| glutInitWindowSize (500, 500); |
| glutInitWindowPosition (100, 100); |
| glutCreateWindow (argv[0]); |
| glutDisplayFunc(display); |
| glutReshapeFunc(reshape); |
| glutKeyboardFunc (keyboard); |
| glutMouseFunc(mouse); |
| glutMainLoop(); |
| return 0; |
| } |