dust3d/thirdparty/carve-1.4.0/lib/geom3d.cpp

165 lines
4.4 KiB
C++

// Begin License:
// Copyright (C) 2006-2008 Tobias Sargeant (tobias.sargeant@gmail.com).
// All rights reserved.
//
// This file is part of the Carve CSG Library (http://carve-csg.com/)
//
// This file may be used under the terms of the GNU General Public
// License version 2.0 as published by the Free Software Foundation
// and appearing in the file LICENSE.GPL2 included in the packaging of
// this file.
//
// This file is provided "AS IS" with NO WARRANTY OF ANY KIND,
// INCLUDING THE WARRANTIES OF DESIGN, MERCHANTABILITY AND FITNESS FOR
// A PARTICULAR PURPOSE.
// End:
#if defined(HAVE_CONFIG_H)
# include <carve_config.h>
#endif
#include <carve/math.hpp>
#include <carve/geom3d.hpp>
#include <algorithm>
namespace carve {
namespace geom3d {
namespace {
int is_same(const std::vector<const Vector *> &a,
const std::vector<const Vector *> &b) {
if (a.size() != b.size()) return false;
const size_t S = a.size();
size_t i, j, p;
for (p = 0; p < S; ++p) {
if (a[0] == b[p]) break;
}
if (p == S) return 0;
for (i = 1, j = p + 1; j < S; ++i, ++j) if (a[i] != b[j]) goto not_fwd;
for ( j = 0; i < S; ++i, ++j) if (a[i] != b[j]) goto not_fwd;
return +1;
not_fwd:
for (i = 1, j = p - 1; j != (size_t)-1; ++i, --j) if (a[i] != b[j]) goto not_rev;
for ( j = S - 1; i < S; ++i, --j) if (a[i] != b[j]) goto not_rev;
return -1;
not_rev:
return 0;
}
}
bool planeIntersection(const Plane &a, const Plane &b, Ray &r) {
Vector N = cross(a.N, b.N);
if (N.isZero()) {
return false;
}
N.normalize();
double dot_aa = dot(a.N, a.N);
double dot_bb = dot(b.N, b.N);
double dot_ab = dot(a.N, b.N);
double determinant = dot_aa * dot_bb - dot_ab * dot_ab;
double c1 = ( a.d * dot_bb - b.d * dot_ab) / determinant;
double c2 = ( b.d * dot_aa - a.d * dot_ab) / determinant;
r.D = N;
r.v = c1 * a.N + c2 * b.N;
return true;
}
IntersectionClass rayPlaneIntersection(const Plane &p,
const Vector &v1,
const Vector &v2,
Vector &v,
double &t) {
Vector Rd = v2 - v1;
double Vd = dot(p.N, Rd);
double V0 = dot(p.N, v1) + p.d;
if (carve::math::ZERO(Vd)) {
if (carve::math::ZERO(V0)) {
return INTERSECT_BAD;
} else {
return INTERSECT_NONE;
}
}
t = -V0 / Vd;
v = v1 + t * Rd;
return INTERSECT_PLANE;
}
IntersectionClass lineSegmentPlaneIntersection(const Plane &p,
const LineSegment &line,
Vector &v) {
double t;
IntersectionClass r = rayPlaneIntersection(p, line.v1, line.v2, v, t);
if (r <= 0) return r;
if ((t < 0.0 && !equal(v, line.v1)) || (t > 1.0 && !equal(v, line.v2)))
return INTERSECT_NONE;
return INTERSECT_PLANE;
}
RayIntersectionClass rayRayIntersection(const Ray &r1,
const Ray &r2,
Vector &v1,
Vector &v2,
double &mu1,
double &mu2) {
if (!r1.OK() || !r2.OK()) return RR_DEGENERATE;
Vector v_13 = r1.v - r2.v;
double d1343 = dot(v_13, r2.D);
double d4321 = dot(r2.D, r1.D);
double d1321 = dot(v_13, r1.D);
double d4343 = dot(r2.D, r2.D);
double d2121 = dot(r1.D, r1.D);
double numer = d1343 * d4321 - d1321 * d4343;
double denom = d2121 * d4343 - d4321 * d4321;
// dc - eb
// -------
// ab - cc
// dc/eb - 1
// ---------
// a/e - cc/eb
// dc/b - e
// --------
// a - cc/b
// d/b - e/c
// ---------
// a/c - c/b
if (denom * double(1<<10) < numer) {
return RR_PARALLEL;
}
mu1 = numer / denom;
mu2 = (d1343 + d4321 * mu1) / d4343;
v1 = r1.v + mu1 * r1.D;
v2 = r2.v + mu2 * r2.D;
return (equal(v1, v2)) ? RR_INTERSECTION : RR_NO_INTERSECTION;
}
}
}