From 7b09710392d35fb55b52031d447a542d99fc6b4b Mon Sep 17 00:00:00 2001 From: Tavian Barnes Date: Tue, 19 Aug 2014 17:10:03 -0400 Subject: Modularize the libdimension codebase. --- libdimension/sphere.c | 114 -------------------------------------------------- 1 file changed, 114 deletions(-) delete mode 100644 libdimension/sphere.c (limited to 'libdimension/sphere.c') diff --git a/libdimension/sphere.c b/libdimension/sphere.c deleted file mode 100644 index d8fae05..0000000 --- a/libdimension/sphere.c +++ /dev/null @@ -1,114 +0,0 @@ -/************************************************************************* - * Copyright (C) 2009-2014 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 * - * . * - *************************************************************************/ - -/** - * @file - * Spheres. - */ - -#include "dimension-internal.h" - -/// Sphere intersection callback. -static bool -dmnsn_sphere_intersection_fn(const dmnsn_object *sphere, dmnsn_line l, - dmnsn_intersection *intersection) -{ - // Solve (x0 + nx*t)^2 + (y0 + ny*t)^2 + (z0 + nz*t)^2 == 1 - double poly[3], x[2]; - poly[2] = dmnsn_vector_dot(l.n, l.n); - poly[1] = 2.0*dmnsn_vector_dot(l.n, l.x0); - poly[0] = dmnsn_vector_dot(l.x0, l.x0) - 1.0; - - size_t n = dmnsn_polynomial_solve(poly, 2, x); - if (n == 0) { - return false; - } - - double t = x[0]; - // Optimize for the case where we're outside the sphere - if (dmnsn_likely(n == 2)) { - t = dmnsn_min(t, x[1]); - } - - intersection->t = t; - intersection->normal = dmnsn_line_point(l, t); - return true; -} - -/// Sphere inside callback. -static bool -dmnsn_sphere_inside_fn(const dmnsn_object *sphere, dmnsn_vector point) -{ - return point.x*point.x + point.y*point.y + point.z*point.z < 1.0; -} - -/// Helper for sphere bounding box calculation. -static inline double -dmnsn_implicit_dot(double row[4]) -{ - double ret = 0.0; - for (int i = 0; i < 3; ++i) { - ret += row[i]*row[i]; - } - return ret; -} - -/// Sphere bounding callback. -static dmnsn_bounding_box -dmnsn_sphere_bounding_fn(const dmnsn_object *object, dmnsn_matrix trans) -{ - // Get a tight bound using the quadric representation of a sphere. For - // details, see - // http://tavianator.com/2014/06/exact-bounding-boxes-for-spheres-ellipsoids - - dmnsn_bounding_box box; - - double cx = trans.n[0][3]; - double dx = sqrt(dmnsn_implicit_dot(trans.n[0])); - box.min.x = cx - dx; - box.max.x = cx + dx; - - double cy = trans.n[1][3]; - double dy = sqrt(dmnsn_implicit_dot(trans.n[1])); - box.min.y = cy - dy; - box.max.y = cy + dy; - - double cz = trans.n[2][3]; - double dz = sqrt(dmnsn_implicit_dot(trans.n[2])); - box.min.z = cz - dz; - box.max.z = cz + dz; - - return box; -} - -/// Sphere vtable. -static const dmnsn_object_vtable dmnsn_sphere_vtable = { - .intersection_fn = dmnsn_sphere_intersection_fn, - .inside_fn = dmnsn_sphere_inside_fn, - .bounding_fn = dmnsn_sphere_bounding_fn, -}; - -dmnsn_object * -dmnsn_new_sphere(dmnsn_pool *pool) -{ - dmnsn_object *sphere = dmnsn_new_object(pool); - sphere->vtable = &dmnsn_sphere_vtable; - return sphere; -} -- cgit v1.2.3