# # 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 # Unpublished-- rights reserved under the copyright laws of the # United States.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. #/ # texgen.c # This program draws a texture mapped teapot with # automatically generated texture coordinates. The # texture is rendered as stripes on the teapot. # Initially, the object is drawn with texture coordinates # based upon the object coordinates of the vertex # and distance from the plane x = 0. Pressing the 'e' # key changes the coordinate generation to eye coordinates # of the vertex. Pressing the 'o' key switches it back # to the object coordinates. Pressing the 's' key # changes the plane to a slanted one (x + y + z = 0). # Pressing the 'x' key switches it back to x = 0. #/ require "opengl" require "glut" require "mathn" StripeImageWidth = 32 $stripeImage = [] $texName; def makeStripeImage for j in (0..StripeImageWidth-1) $stripeImage[4*j] = if (j<=4) then 255; else 0; end; $stripeImage[4*j+1] = if (j>4) then 255 else 0; end; $stripeImage[4*j+2] = 0; $stripeImage[4*j+3] = 255; end end #* planes for texture coordinate generation */ $xequalzero = [1.0, 0.0, 0.0, 0.0]; $slanted = [1.0, 1.0, 1.0, 0.0]; $currentCoeff = nil; $currentPlane = nil; $currentGenMode = nil; def init GL.ClearColor(0.0, 0.0, 0.0, 0.0); GL.Enable(GL::DEPTH_TEST); GL.ShadeModel(GL::SMOOTH); makeStripeImage(); GL.PixelStorei(GL::UNPACK_ALIGNMENT, 1); $texName = GL.GenTextures(1); GL.BindTexture(GL::TEXTURE_2D, $texName[0]); GL.TexParameteri(GL::TEXTURE_2D, GL::TEXTURE_WRAP_S, GL::REPEAT); GL.TexParameteri(GL::TEXTURE_2D, GL::TEXTURE_MAG_FILTER, GL::LINEAR); GL.TexParameteri(GL::TEXTURE_2D, GL::TEXTURE_MIN_FILTER, GL::LINEAR); GL.TexImage2D(GL::TEXTURE_2D, 0, GL::RGBA, StripeImageWidth, 1, 0, GL::RGBA, GL::UNSIGNED_BYTE, $stripeImage.pack("C*")); GL.TexEnvf(GL::TEXTURE_ENV, GL::TEXTURE_ENV_MODE, GL::MODULATE); $currentCoeff = $xequalzero; $currentGenMode = GL::OBJECT_LINEAR; $currentPlane = GL::OBJECT_PLANE; GL.TexGen(GL::S, GL::TEXTURE_GEN_MODE, $currentGenMode); GL.TexGen(GL::S, $currentPlane, $currentCoeff); GL.Enable(GL::TEXTURE_GEN_S); GL.Enable(GL::TEXTURE_2D); GL.Enable(GL::CULL_FACE); GL.Enable(GL::LIGHTING); GL.Enable(GL::LIGHT0); GL.Enable(GL::AUTO_NORMAL); GL.Enable(GL::NORMALIZE); GL.FrontFace(GL::CW); GL.CullFace(GL::BACK); GL.Material(GL::FRONT, GL::SHININESS, 64.0); end display = Proc.new { GL.Clear(GL::COLOR_BUFFER_BIT | GL::DEPTH_BUFFER_BIT); GL.PushMatrix(); GL.Rotate(45.0, 0.0, 0.0, 1.0); GL.BindTexture(GL::TEXTURE_2D, $texName[0]); GLUT.SolidTeapot(2.0); GL.PopMatrix(); GL.Flush(); } reshape = Proc.new {|w, h| GL.Viewport(0, 0, w, h); GL.MatrixMode(GL::PROJECTION); GL.LoadIdentity(); if (w <= h) GL.Ortho(-3.5, 3.5, -3.5*h/w,3.5*h/w, -3.5, 3.5); else GL.Ortho(-3.5*w/h, 3.5*w/h, -3.5, 3.5, -3.5, 3.5); end GL.MatrixMode(GL::MODELVIEW); GL.LoadIdentity(); } #* ARGSUSED1 */ keyboard = Proc.new {|key, x, y| case (key) when 'e'[0],'E'[0] $currentGenMode = GL::EYE_LINEAR; $currentPlane = GL::EYE_PLANE; GL.TexGen(GL::S, GL::TEXTURE_GEN_MODE, $currentGenMode); GL.TexGen(GL::S, $currentPlane, $currentCoeff); GLUT.PostRedisplay(); when 'o'[0], 'O'[0] $currentGenMode = GL::OBJECT_LINEAR; $currentPlane = GL::OBJECT_PLANE; GL.TexGen(GL::S, GL::TEXTURE_GEN_MODE, $currentGenMode); GL.TexGen(GL::S, $currentPlane, $currentCoeff); GLUT.PostRedisplay(); when 's'[0],'S'[0] $currentCoeff = $slanted; GL.TexGen(GL::S, $currentPlane, $currentCoeff); GLUT.PostRedisplay(); when 'x'[0],'X'[0] $currentCoeff = $xequalzero; GL.TexGen(GL::S, $currentPlane, $currentCoeff); GLUT.PostRedisplay(); when 27 exit(0); end } GLUT.Init GLUT.InitDisplayMode (GLUT::SINGLE | GLUT::RGB | GLUT::DEPTH); GLUT.InitWindowSize(256, 256); GLUT.InitWindowPosition(100, 100); GLUT.CreateWindow ($0); init(); GLUT.DisplayFunc(display); GLUT.ReshapeFunc(reshape); GLUT.KeyboardFunc(keyboard); GLUT.MainLoop();