# #/* Copyright (c) Mark J. Kilgard, 1994. */ # #/* # * (c) Copyright 1993, 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 # * Unpublished-- rights reserved under the copyright laws of the # * United States.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(TM) is a trademark of Silicon Graphics, Inc. # */ #/* # * pickdepth.c # * Picking is demonstrated in this program. In # * rendering mode, three overlapping rectangles are # * drawn. When the left mouse button is pressed, # * selection mode is entered with the picking matrix. # * Rectangles which are drawn under the cursor position # * are "picked." Pay special attention to the depth # * value range, which is returned. # */ require "opengl" require "glut" def myinit GL::ClearColor(0.0, 0.0, 0.0, 0.0); GL::DepthFunc(GL::LESS); GL::Enable(GL::DEPTH_TEST); GL::ShadeModel(GL::FLAT); GL::DepthRange(0.0, 1.0); #/* The default z mapping */ end #/* The three rectangles are drawn. In selection mode, # * each rectangle is given the same name. Note that # * each rectangle is drawn with a different z value. # */ def drawRects(mode) if (mode == GL::SELECT) GL::LoadName(1); end GL::Begin(GL::QUADS); GL::Color(1.0, 1.0, 0.0); GL::Vertex(2, 0, 0); GL::Vertex(2, 6, 0); GL::Vertex(6, 6, 0); GL::Vertex(6, 0, 0); GL::End(); if (mode == GL::SELECT) GL::LoadName(2); end GL::Begin(GL::QUADS); GL::Color(0.0, 1.0, 1.0); GL::Vertex(3, 2, -1); GL::Vertex(3, 8, -1); GL::Vertex(8, 8, -1); GL::Vertex(8, 2, -1); GL::End(); if (mode == GL::SELECT) GL::LoadName(3); end GL::Begin(GL::QUADS); GL::Color(1.0, 0.0, 1.0); GL::Vertex(0, 2, -2); GL::Vertex(0, 7, -2); GL::Vertex(5, 7, -2); GL::Vertex(5, 2, -2); GL::End(); end #/* processHits() prints out the contents of the # * selection array. # */ def processHits(hits, buffer) printf("hits = %d\n", hits); ptr = buffer.unpack("I*") p = 0 for i in 0...hits #/* for each hit */ names = ptr[p] printf(" number of names for hit = %d\n", names); p+=1; printf(" z1 is %g;", ptr[p].to_f/0xffffffff); p+=1; printf(" z2 is %g\n", ptr[p].to_f/0xffffffff); p+=1; printf(" the name is "); for j in 0...names # /* for each name */ printf("%d ", ptr[p]); p+=1 end printf("\n"); end end #/* pickRects() sets up selection mode, name stack, # * and projection matrix for picking. Then the objects # * are drawn. # */ BUFSIZE=512 pickRects = proc {|button, state, x, y| if (button == GLUT::LEFT_BUTTON && state == GLUT::DOWN) viewport = GL::GetDoublev(GL::VIEWPORT); selectBuf = GL::SelectBuffer(BUFSIZE); GL::RenderMode(GL::SELECT); GL::InitNames(); GL::PushName(~0); GL::MatrixMode(GL::PROJECTION); GL::PushMatrix(); GL::LoadIdentity(); #/* create 5x5 pixel picking region near cursor location */ GLU::PickMatrix( x, viewport[3] - y, 5.0, 5.0, viewport); GL::Ortho(0.0, 8.0, 0.0, 8.0, -0.5, 2.5); drawRects(GL::SELECT); GL::PopMatrix(); GL::Flush(); hits = GL::RenderMode(GL::RENDER); processHits(hits, selectBuf); end } display = proc { GL::Clear(GL::COLOR_BUFFER_BIT | GL::DEPTH_BUFFER_BIT); drawRects(GL::RENDER); GLUT::SwapBuffers(); } myReshape = proc {|w, h| GL::Viewport(0, 0, w, h); GL::MatrixMode(GL::PROJECTION); GL::LoadIdentity(); GL::Ortho(0.0, 8.0, 0.0, 8.0, -0.5, 2.5); GL::MatrixMode(GL::MODELVIEW); GL::LoadIdentity(); } #/* Main Loop # * Open window with initial window size, title bar, # * RGBA display mode, depth buffer, and handle input events. # */ GLUT::InitWindowSize(200, 200); GLUT::InitDisplayMode(GLUT::DOUBLE | GLUT::RGB | GLUT::DEPTH); GLUT::Init(); GLUT::CreateWindow(); myinit(); GLUT::MouseFunc(pickRects); GLUT::ReshapeFunc(myReshape); GLUT::DisplayFunc(display); GLUT::MainLoop();