(* 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 * Unpublished-- rights reserved under the copyright laws of the * United States.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. *) (* stencil.ml * This program draws two rotated tori in a window. * A diamond in the center of the window masks out part * of the scene. Within this mask, a different model * (a sphere) is drawn in a different color. *) (* !!! NOTE !!! * * This demo is poorly written. The stencil buffer should be * redrawn in display(), not in the reshape() function. * The reason is if the window gets "damaged" then the stencil buffer * contents will be in an undefined state (reshape is not called when * a window is damaged and needs to be redrawn). If the stencil buffer * contents are undefined, the results of display() are unpredictable. * * -Brian *) (* OCaml version by Florent Monnier *) open GL open Glu open Glut let yellow_mat = 1 let blue_mat = 2 let myinit () = let yellow_diffuse = (0.7, 0.7, 0.0, 1.0) and yellow_specular = (1.0, 1.0, 1.0, 1.0) and blue_diffuse = (0.1, 0.1, 0.7, 1.0) and blue_specular = (0.1, 1.0, 1.0, 1.0) and position_one = (1.0, 1.0, 1.0, 0.0) in glNewList yellow_mat GL_COMPILE; glMaterial GL_FRONT (Material.GL_DIFFUSE yellow_diffuse); glMaterial GL_FRONT (Material.GL_SPECULAR yellow_specular); glMaterial GL_FRONT (Material.GL_SHININESS 64.0); glEndList(); glNewList blue_mat GL_COMPILE; glMaterial GL_FRONT (Material.GL_DIFFUSE blue_diffuse); glMaterial GL_FRONT (Material.GL_SPECULAR blue_specular); glMaterial GL_FRONT (Material.GL_SHININESS 45.0); glEndList(); glLight (GL_LIGHT 0) (Light.GL_POSITION position_one); glEnable GL_LIGHT0; glEnable GL_LIGHTING; glDepthFunc GL_LESS; glEnable GL_DEPTH_TEST; glClearStencil 0x0; glEnable GL_STENCIL_TEST; ;; (* Draw a sphere in a diamond-shaped section in the * middle of a window with 2 tori. *) let display() = glClear[GL_COLOR_BUFFER_BIT; GL_DEPTH_BUFFER_BIT]; glStencilOp GL_KEEP GL_KEEP GL_KEEP; (* draw blue sphere where the stencil is 1 *) glStencilFunc GL_EQUAL 0x1 0x1; glCallList blue_mat; glutSolidSphere 0.5 15 15; (* draw the tori where the stencil is not 1 *) glStencilFunc GL_NOTEQUAL 0x1 0x1; glPushMatrix(); glRotate 45.0 0.0 0.0 1.0; glRotate 45.0 0.0 1.0 0.0; glCallList yellow_mat; glutSolidTorus 0.275 0.85 15 15; glPushMatrix(); glRotate 90.0 1.0 0.0 0.0; glutSolidTorus 0.275 0.85 15 15; glPopMatrix(); glPopMatrix(); glFlush(); glutSwapBuffers(); ;; (* Whenever the window is reshaped, redefine the * coordinate system and redraw the stencil area. *) let reshape ~width:w ~height:h = glViewport 0 0 w h; glClear [GL_STENCIL_BUFFER_BIT]; (* create a diamond shaped stencil area *) glMatrixMode GL_PROJECTION; glLoadIdentity(); glOrtho(-3.0) (3.0) (-3.0) (3.0) (-1.0) (1.0); glMatrixMode GL_MODELVIEW; glLoadIdentity(); glStencilFunc GL_ALWAYS 0x1 0x1; glStencilOp GL_REPLACE GL_REPLACE GL_REPLACE; glBegin GL_QUADS; glVertex2 (-1.0) ( 0.0); glVertex2 ( 0.0) ( 1.0); glVertex2 ( 1.0) ( 0.0); glVertex2 ( 0.0) (-1.0); glEnd(); glMatrixMode GL_PROJECTION; glLoadIdentity(); gluPerspective 45.0 ((float w)/.(float h)) 3.0 7.0; glMatrixMode GL_MODELVIEW; glLoadIdentity(); glTranslate 0.0 0.0 (-5.0); ;; let keyboard ~key ~x ~y = begin match key with | '\027' -> (* Escape *) exit 0; | _ -> () end; glutPostRedisplay(); ;; (* Main Loop * Open window with initial window size, title bar, * RGBA display mode, and handle input events. *) let () = ignore(glutInit Sys.argv); glutInitDisplayMode [GLUT_DOUBLE; GLUT_RGB; GLUT_DEPTH; GLUT_STENCIL]; glutInitWindowSize 400 400; ignore(glutCreateWindow Sys.argv.(0)); myinit(); glutReshapeFunc ~reshape; glutDisplayFunc ~display; glutKeyboardFunc ~keyboard; glutMainLoop(); ;;