# #/* 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 # * Unpublished-- rights reserved under the copyright laws of the # * United States.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. # */ #/* checker.c # * This program texture maps a checkerboard image onto # * two rectangles. This program clamps the texture, if # * the texture coordinates fall outside 0.0 and 1.0. # */ require "opengl" require "glut" require "mathn" #/* Create checkerboard texture */ CheckImageWidth=64 CheckImageHeight=64 $checkImage = [] def makeCheckImage for i in 0..CheckImageWidth-1 for j in 0..CheckImageHeight-1 c = if ((i&0x8==0) != (j&0x8==0)) then 255; else 0; end; $checkImage[(i+CheckImageWidth*j)*3+0] = c; $checkImage[(i+CheckImageWidth*j)*3+1] = c; $checkImage[(i+CheckImageWidth*j)*3+2] = c; end end end def myinit GL.ClearColor(0.0, 0.0, 0.0, 0.0); GL.Enable(GL::DEPTH_TEST); GL.DepthFunc(GL::LESS); makeCheckImage(); GL.PixelStore(GL::UNPACK_ALIGNMENT, 1); GL.TexImage2D(GL::TEXTURE_2D, 0, 3, CheckImageWidth, CheckImageHeight, 0, GL::RGB, GL::UNSIGNED_BYTE, $checkImage.pack("C*")); GL.TexParameter(GL::TEXTURE_2D, GL::TEXTURE_WRAP_S, GL::CLAMP); GL.TexParameter(GL::TEXTURE_2D, GL::TEXTURE_WRAP_T, GL::CLAMP); GL.TexParameter(GL::TEXTURE_2D, GL::TEXTURE_MAG_FILTER, GL::LINEAR); GL.TexParameter(GL::TEXTURE_2D, GL::TEXTURE_MIN_FILTER, GL::LINEAR); GL.TexEnv(GL::TEXTURE_ENV, GL::TEXTURE_ENV_MODE, GL::DECAL); GL.Enable(GL::TEXTURE_2D); GL.ShadeModel(GL::FLAT); end display = Proc.new { GL.Clear(GL::COLOR_BUFFER_BIT | GL::DEPTH_BUFFER_BIT); GL.Begin(GL::QUADS); GL.TexCoord(0.0, 0.0); GL.Vertex(-2.0, -1.0, 0.0); GL.TexCoord(0.0, 1.0); GL.Vertex(-2.0, 1.0, 0.0); GL.TexCoord(1.0, 1.0); GL.Vertex(0.0, 1.0, 0.0); GL.TexCoord(1.0, 0.0); GL.Vertex(0.0, -1.0, 0.0); GL.TexCoord(0.0, 0.0); GL.Vertex(1.0, -1.0, 0.0); GL.TexCoord(0.0, 1.0); GL.Vertex(1.0, 1.0, 0.0); GL.TexCoord(1.0, 1.0); GL.Vertex(2.41421, 1.0, -1.41421); GL.TexCoord(1.0, 0.0); GL.Vertex(2.41421, -1.0, -1.41421); GL.End(); GLUT.SwapBuffers(); } myReshape = Proc.new {|w, h| GL.Viewport(0, 0, w, h); GL.MatrixMode(GL::PROJECTION); GL.LoadIdentity(); GLU.Perspective(60.0, 1.0*w/h, 1.0, 30.0); GL.MatrixMode(GL::MODELVIEW); GL.LoadIdentity(); GL.Translate(0.0, 0.0, -3.6); } #int #main(int argc, char** argv) #{ GLUT.Init GLUT.InitDisplayMode(GLUT::DOUBLE | GLUT::RGB | GLUT::DEPTH); GLUT.CreateWindow("checker"); myinit(); GLUT.ReshapeFunc (myReshape); GLUT.DisplayFunc(display); GLUT.MainLoop();