From 9563ecb2efb2eec6d83fa4f73b75dfb4dccbc34c Mon Sep 17 00:00:00 2001 From: Tavian Barnes Date: Thu, 15 Apr 2010 15:16:07 -0400 Subject: Add plane object. --- libdimension/plane.c | 83 ++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 83 insertions(+) create mode 100644 libdimension/plane.c (limited to 'libdimension/plane.c') diff --git a/libdimension/plane.c b/libdimension/plane.c new file mode 100644 index 0000000..e475c46 --- /dev/null +++ b/libdimension/plane.c @@ -0,0 +1,83 @@ +/************************************************************************* + * Copyright (C) 2010 Tavian Barnes * + * * + * This file is part of The Dimension Library. * + * * + * The Dimension Library is free software; you can redistribute it and/ * + * or modify it under the terms of the GNU Lesser General Public License * + * as published by the Free Software Foundation; either version 3 of the * + * License, or (at your option) any later version. * + * * + * The Dimension Library 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 * + * Lesser General Public License for more details. * + * * + * You should have received a copy of the GNU Lesser General Public * + * License along with this program. If not, see * + * . * + *************************************************************************/ + +#include "dimension.h" +#include + +/* + * Plane + */ + +/* Plane object callbacks */ + +static bool dmnsn_plane_intersection_fn(const dmnsn_object *plane, + dmnsn_line line, + dmnsn_intersection *intersection); +static bool dmnsn_plane_inside_fn(const dmnsn_object *plane, + dmnsn_vector point); + +/* Allocate a new plane */ +dmnsn_object * +dmnsn_new_plane(dmnsn_vector normal) +{ + dmnsn_object *plane = dmnsn_new_object(); + + dmnsn_vector *param = dmnsn_malloc(sizeof(dmnsn_vector)); + *param = normal; + + plane->intersection_fn = &dmnsn_plane_intersection_fn; + plane->inside_fn = &dmnsn_plane_inside_fn; + plane->free_fn = &free; + plane->bounding_box.min = dmnsn_new_vector(-INFINITY, -INFINITY, -INFINITY); + plane->bounding_box.max = dmnsn_new_vector(INFINITY, INFINITY, INFINITY); + plane->ptr = param; + return plane; +} + +/* Returns the closest intersection of `line' with `plane' */ +static bool +dmnsn_plane_intersection_fn(const dmnsn_object *plane, dmnsn_line line, + dmnsn_intersection *intersection) +{ + dmnsn_vector *normal = plane->ptr; + + dmnsn_line line_trans = dmnsn_matrix_line_mul(plane->trans_inv, line); + double den = dmnsn_vector_dot(line_trans.n, *normal); + if (den != 0.0) { + double t = -dmnsn_vector_dot(line_trans.x0, *normal)/den; + if (t >= 0.0) { + intersection->ray = line; + intersection->t = t; + intersection->normal = dmnsn_matrix_normal_mul(plane->trans, *normal); + intersection->texture = plane->texture; + intersection->interior = plane->interior; + return true; + } + } + return false; +} + +/* Return whether a point is inside a plane (x**2 + y**2 + z**2 < 1.0) */ +static bool +dmnsn_plane_inside_fn(const dmnsn_object *plane, dmnsn_vector point) +{ + dmnsn_vector *normal = plane->ptr; + return dmnsn_vector_dot(point, *normal) < 0.0; +} -- cgit v1.2.3