# # 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 # Unpublished-- rights reserved under the copyright laws of the # United States.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. #/ # # movelight.c # This program demonstrates when to issue lighting and # transformation commands to render a model with a light # which is moved by a modeling transformation (rotate or # translate). The light position is reset after the modeling # transformation is called. The eye position does not change. # # A sphere is drawn using a grey material characteristic. # A single light source illuminates the object. # # Interaction: pressing the left mouse button alters # the modeling transformation (x rotation) by 30 degrees. # The scene is then redrawn with the light in a new position. #/ require "opengl" require "glut" require "rational" require "mathn" $spin = 0; # Initialize material property, light source, lighting model, # and depth buffer. #/ def init GL.ClearColor(0.0, 0.0, 0.0, 0.0); GL.ShadeModel(GL::SMOOTH); GL.Enable(GL::LIGHTING); GL.Enable(GL::LIGHT0); GL.Enable(GL::DEPTH_TEST); end # Here is where the light position is reset after the modeling # transformation (glRotated) is called. This places the # light at a new position in world coordinates. The cube # represents the position of the light. #/ display = Proc.new { position = [ 0.0, 0.0, 1.5, 1.0 ]; GL.Clear(GL::COLOR_BUFFER_BIT | GL::DEPTH_BUFFER_BIT); GL.PushMatrix(); GLU.LookAt(0.0, 0.0, 5.0, 0.0, 0.0, 0.0, 0.0, 1.0, 0.0); GL.PushMatrix(); GL.Rotate($spin, 1.0, 0.0, 0.0); GL.Light(GL::LIGHT0, GL::POSITION, position); GL.Translate(0.0, 0.0, 1.5); GL.Disable(GL::LIGHTING); GL.Color(0.0, 1.0, 1.0); GLUT.WireCube(0.1); GL.Enable(GL::LIGHTING); GL.PopMatrix(); GLUT.SolidTorus(0.275, 0.85, 8, 15); GL.PopMatrix(); GL.Flush(); } reshape = Proc.new {|w, h| GL.Viewport(0, 0, w, h); GL.MatrixMode(GL::PROJECTION); GL.LoadIdentity(); # GLU.Perspective(40.0, Rational(w,h), 1.0, 20.0); GLU.Perspective(40.0, w/h, 1.0, 20.0); GL.MatrixMode(GL::MODELVIEW); GL.LoadIdentity(); } # ARGSUSED2 */ mouse = Proc.new {|button, state, x, y| case button when GLUT::LEFT_BUTTON if (state == GLUT::DOWN) $spin = ($spin + 30) % 360; GLUT.PostRedisplay(); end end } # ARGSUSED1 */ keyboard = Proc.new {|key, x, y| case key when 27 exit(0); end } GLUT.Init GLUT.InitDisplayMode(GLUT::SINGLE | GLUT::RGB | GLUT::DEPTH); GLUT.InitWindowSize(500, 500); GLUT.InitWindowPosition(100, 100); GLUT.CreateWindow($0); init(); GLUT.DisplayFunc(display); GLUT.ReshapeFunc(reshape); GLUT.MouseFunc(mouse); GLUT.KeyboardFunc(keyboard); GLUT.MainLoop();