181 lines
5.4 KiB
C
181 lines
5.4 KiB
C
/*
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* (c) Copyright 1993, Silicon Graphics, Inc.
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* ALL RIGHTS RESERVED
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* Permission to use, copy, modify, and distribute this software for
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* any purpose and without fee is hereby granted, provided that the above
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* copyright notice appear in all copies and that both the copyright notice
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* and this permission notice appear in supporting documentation, and that
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* the name of Silicon Graphics, Inc. not be used in advertising
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* or publicity pertaining to distribution of the software without specific,
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* written prior permission.
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*
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* THE MATERIAL EMBODIED ON THIS SOFTWARE IS PROVIDED TO YOU "AS-IS"
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* AND WITHOUT WARRANTY OF ANY KIND, EXPRESS, IMPLIED OR OTHERWISE,
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* INCLUDING WITHOUT LIMITATION, ANY WARRANTY OF MERCHANTABILITY OR
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* FITNESS FOR A PARTICULAR PURPOSE. IN NO EVENT SHALL SILICON
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* GRAPHICS, INC. BE LIABLE TO YOU OR ANYONE ELSE FOR ANY DIRECT,
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* SPECIAL, INCIDENTAL, INDIRECT OR CONSEQUENTIAL DAMAGES OF ANY
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* KIND, OR ANY DAMAGES WHATSOEVER, INCLUDING WITHOUT LIMITATION,
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* LOSS OF PROFIT, LOSS OF USE, SAVINGS OR REVENUE, OR THE CLAIMS OF
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* THIRD PARTIES, WHETHER OR NOT SILICON GRAPHICS, INC. HAS BEEN
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* ADVISED OF THE POSSIBILITY OF SUCH LOSS, HOWEVER CAUSED AND ON
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* ANY THEORY OF LIABILITY, ARISING OUT OF OR IN CONNECTION WITH THE
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* POSSESSION, USE OR PERFORMANCE OF THIS SOFTWARE.
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*
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* US Government Users Restricted Rights
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* Use, duplication, or disclosure by the Government is subject to
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* restrictions set forth in FAR 52.227.19(c)(2) or subparagraph
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* (c)(1)(ii) of the Rights in Technical Data and Computer Software
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* clause at DFARS 252.227-7013 and/or in similar or successor
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* clauses in the FAR or the DOD or NASA FAR Supplement.
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* Unpublished-- rights reserved under the copyright laws of the
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* United States. Contractor/manufacturer is Silicon Graphics,
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* Inc., 2011 N. Shoreline Blvd., Mountain View, CA 94039-7311.
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*
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* OpenGL(TM) is a trademark of Silicon Graphics, Inc.
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*/
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/*
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* pickdepth.c
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* Picking is demonstrated in this program. In
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* rendering mode, three overlapping rectangles are
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* drawn. When the left mouse button is pressed,
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* selection mode is entered with the picking matrix.
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* Rectangles which are drawn under the cursor position
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* are "picked." Pay special attention to the depth
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* value range, which is returned.
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*/
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#include <windows.h>
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#include <stdio.h>
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#include <GL/gl.h>
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#include <GL/glu.h>
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#include "glaux.h"
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void myinit(void)
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{
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glClearColor (0.0, 0.0, 0.0, 0.0);
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glDepthFunc(GL_LESS);
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glEnable(GL_DEPTH_TEST);
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glShadeModel(GL_FLAT);
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glDepthRange (0.0, 1.0); /* The default z mapping */
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}
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/* The three rectangles are drawn. In selection mode,
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* each rectangle is given the same name. Note that
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* each rectangle is drawn with a different z value.
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*/
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void drawRects(GLenum mode)
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{
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if (mode == GL_SELECT)
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glLoadName (1);
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glBegin (GL_QUADS);
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glColor3f (1.0, 1.0, 0.0);
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glVertex3i (2, 0, 0);
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glVertex3i (2, 6, 0);
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glVertex3i (6, 6, 0);
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glVertex3i (6, 0, 0);
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glColor3f (0.0, 1.0, 1.0);
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glVertex3i (3, 2, -1);
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glVertex3i (3, 8, -1);
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glVertex3i (8, 8, -1);
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glVertex3i (8, 2, -1);
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glColor3f (1.0, 0.0, 1.0);
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glVertex3i (0, 2, -2);
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glVertex3i (0, 7, -2);
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glVertex3i (5, 7, -2);
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glVertex3i (5, 2, -2);
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glEnd ();
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}
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/* processHits() prints out the contents of the
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* selection array.
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*/
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void processHits (GLint hits, GLuint buffer[])
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{
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unsigned int i, j;
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GLuint names, *ptr;
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printf ("hits = %d\n", hits);
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ptr = (GLuint *) buffer;
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for (i = 0; i < hits; i++) { /* for each hit */
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names = *ptr;
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printf (" number of names for hit = %d\n", names); ptr++;
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printf (" z1 is %u;", *ptr); ptr++;
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printf (" z2 is %u\n", *ptr); ptr++;
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printf (" the name is ");
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for (j = 0; j < names; j++) { /* for each name */
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printf ("%d ", *ptr); ptr++;
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}
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printf ("\n");
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}
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}
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/* pickRects() sets up selection mode, name stack,
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* and projection matrix for picking. Then the objects
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* are drawn.
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*/
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#define BUFSIZE 512
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void pickRects(AUX_EVENTREC *event)
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{
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GLuint selectBuf[BUFSIZE];
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GLint hits;
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GLint viewport[4];
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int x, y;
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x = event->data[AUX_MOUSEX];
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y = event->data[AUX_MOUSEY];
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glGetIntegerv (GL_VIEWPORT, viewport);
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glSelectBuffer (BUFSIZE, selectBuf);
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(void) glRenderMode (GL_SELECT);
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glInitNames();
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glPushName(-1);
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glMatrixMode (GL_PROJECTION);
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glPushMatrix ();
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glLoadIdentity ();
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/* create 5x5 pixel picking region near cursor location */
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gluPickMatrix ((GLdouble) x, (GLdouble) (viewport[3] - y),
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5.0, 5.0, viewport);
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glOrtho (0.0, 8.0, 0.0, 8.0, -0.5, 2.5);
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drawRects (GL_SELECT);
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glPopMatrix ();
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glFlush ();
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hits = glRenderMode (GL_RENDER);
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processHits (hits, selectBuf);
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}
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void display(void)
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{
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glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
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drawRects (GL_RENDER);
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glFlush();
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}
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void myReshape(GLsizei w, GLsizei h)
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{
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glViewport(0, 0, w, h);
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glMatrixMode(GL_PROJECTION);
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glLoadIdentity();
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glOrtho (0.0, 8.0, 0.0, 8.0, 0.0, 2.0);
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glMatrixMode(GL_MODELVIEW);
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glLoadIdentity();
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}
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/* Main Loop
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* Open window with initial window size, title bar,
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* RGBA display mode, depth buffer, and handle input events.
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*/
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int main(int argc, char** argv)
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{
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auxInitDisplayMode (AUX_SINGLE | AUX_RGB | AUX_DEPTH16);
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auxInitPosition (0, 0, 100, 100);
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auxInitWindow (argv[0]);
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myinit ();
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auxMouseFunc (AUX_LEFTBUTTON, AUX_MOUSEDOWN, pickRects);
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auxReshapeFunc (myReshape);
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auxMainLoop(display);
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}
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