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authorTavian Barnes <tavianator@tavianator.com>2014-08-19 17:10:03 -0400
committerTavian Barnes <tavianator@tavianator.com>2015-10-25 11:03:56 -0400
commit7b09710392d35fb55b52031d447a542d99fc6b4b (patch)
tree270eb927ee8c52ceeb99926ebf4843704775a610 /libdimension/sphere.c
parent200c86b91ea7063d35be3bffc11c5da53c054653 (diff)
downloaddimension-7b09710392d35fb55b52031d447a542d99fc6b4b.tar.xz
Modularize the libdimension codebase.
Diffstat (limited to 'libdimension/sphere.c')
-rw-r--r--libdimension/sphere.c114
1 files changed, 0 insertions, 114 deletions
diff --git a/libdimension/sphere.c b/libdimension/sphere.c
deleted file mode 100644
index d8fae05..0000000
--- a/libdimension/sphere.c
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@@ -1,114 +0,0 @@
-/*************************************************************************
- * Copyright (C) 2009-2014 Tavian Barnes <tavianator@tavianator.com> *
- * *
- * 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 *
- * <http://www.gnu.org/licenses/>. *
- *************************************************************************/
-
-/**
- * @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;
-}