| /* |
| Copyright 2005-2010 Intel Corporation. All Rights Reserved. |
| |
| This file is part of Threading Building Blocks. |
| |
| Threading Building Blocks is free software; you can redistribute it |
| and/or modify it under the terms of the GNU General Public License |
| version 2 as published by the Free Software Foundation. |
| |
| Threading Building Blocks is distributed in the hope that it will be |
| useful, but WITHOUT ANY WARRANTY; without even the implied warranty |
| of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| GNU General Public License for more details. |
| |
| You should have received a copy of the GNU General Public License |
| along with Threading Building Blocks; if not, write to the Free Software |
| Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA |
| |
| As a special exception, you may use this file as part of a free software |
| library without restriction. Specifically, if other files instantiate |
| templates or use macros or inline functions from this file, or you compile |
| this file and link it with other files to produce an executable, this |
| file does not by itself cause the resulting executable to be covered by |
| the GNU General Public License. This exception does not however |
| invalidate any other reasons why the executable file might be covered by |
| the GNU General Public License. |
| */ |
| |
| /* |
| The original source for this example is |
| Copyright (c) 1994-2008 John E. Stone |
| All rights reserved. |
| |
| Redistribution and use in source and binary forms, with or without |
| modification, are permitted provided that the following conditions |
| are met: |
| 1. Redistributions of source code must retain the above copyright |
| notice, this list of conditions and the following disclaimer. |
| 2. Redistributions in binary form must reproduce the above copyright |
| notice, this list of conditions and the following disclaimer in the |
| documentation and/or other materials provided with the distribution. |
| 3. The name of the author may not be used to endorse or promote products |
| derived from this software without specific prior written permission. |
| |
| THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS |
| OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED |
| WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE |
| ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY |
| DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL |
| DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS |
| OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) |
| HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT |
| LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY |
| OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF |
| SUCH DAMAGE. |
| */ |
| |
| /* |
| * ring.c - This file contains the functions for dealing with rings. |
| * |
| * $Id: ring.cpp,v 1.1.1.1 2012/03/29 17:22:19 uid42307 Exp $ |
| */ |
| |
| #include "machine.h" |
| #include "types.h" |
| #include "macros.h" |
| #include "vector.h" |
| #include "intersect.h" |
| #include "util.h" |
| |
| #define RING_PRIVATE |
| #include "ring.h" |
| |
| static object_methods ring_methods = { |
| (void (*)(void *, void *))(ring_intersect), |
| (void (*)(void *, void *, void *, void *))(ring_normal), |
| ring_bbox, |
| free |
| }; |
| |
| object * newring(void * tex, vector ctr, vector norm, flt inrad, flt outrad) { |
| ring * r; |
| |
| r=(ring *) rt_getmem(sizeof(ring)); |
| memset(r, 0, sizeof(ring)); |
| r->methods = &ring_methods; |
| |
| r->tex = (texture *)tex; |
| r->ctr = ctr; |
| r->norm = norm; |
| r->inrad = inrad; |
| r->outrad= outrad; |
| |
| return (object *) r; |
| } |
| |
| static int ring_bbox(void * obj, vector * min, vector * max) { |
| ring * r = (ring *) obj; |
| |
| min->x = r->ctr.x - r->outrad; |
| min->y = r->ctr.y - r->outrad; |
| min->z = r->ctr.z - r->outrad; |
| max->x = r->ctr.x + r->outrad; |
| max->y = r->ctr.y + r->outrad; |
| max->z = r->ctr.z + r->outrad; |
| |
| return 1; |
| } |
| |
| static void ring_intersect(ring * rng, ray * ry) { |
| flt d; |
| flt t,td; |
| vector hit, pnt; |
| |
| d = -VDot(&(rng->ctr), &(rng->norm)); |
| |
| t=-(d+VDot(&(rng->norm), &(ry->o))); |
| td=VDot(&(rng->norm),&(ry->d)); |
| if (td != 0.0) { |
| t= t / td; |
| if (t>=0.0) { |
| hit=Raypnt(ry, t); |
| VSUB(hit, rng->ctr, pnt); |
| VDOT(td, pnt, pnt); |
| td=sqrt(td); |
| if ((td > rng->inrad) && (td < rng->outrad)) |
| add_intersection(t,(object *) rng, ry); |
| } |
| } |
| } |
| |
| static void ring_normal(ring * rng, vector * pnt, ray * incident, vector * N) { |
| *N=rng->norm; |
| VNorm(N); |
| if (VDot(N, &(incident->d)) > 0.0) { |
| N->x=-N->x; |
| N->y=-N->y; |
| N->z=-N->z; |
| } |
| } |
| |