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blender-archive/source/blender/blenlib/intern/math_vec.cc

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/*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License
* as published by the Free Software Foundation; either version 2
* of the License, or (at your option) any later version.
*
* This program 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 this program; if not, write to the Free Software Foundation,
* Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
*/
/** \file
* \ingroup bli
*/
#include "BLI_double2.hh"
#include "BLI_double3.hh"
#include "BLI_float2.hh"
#include "BLI_float3.hh"
#include "BLI_hash.hh"
#include "BLI_math_mpq.hh"
#include "BLI_mpq2.hh"
#include "BLI_mpq3.hh"
#include "BLI_span.hh"
#include "BLI_utildefines.h"
namespace blender {
float2::isect_result float2::isect_seg_seg(const float2 &v1,
const float2 &v2,
const float2 &v3,
const float2 &v4)
{
float2::isect_result ans;
float div = (v2[0] - v1[0]) * (v4[1] - v3[1]) - (v2[1] - v1[1]) * (v4[0] - v3[0]);
if (div == 0.0f) {
ans.lambda = 0.0f;
ans.mu = 0.0f;
ans.kind = float2::isect_result::LINE_LINE_COLINEAR;
}
else {
ans.lambda = ((v1[1] - v3[1]) * (v4[0] - v3[0]) - (v1[0] - v3[0]) * (v4[1] - v3[1])) / div;
ans.mu = ((v1[1] - v3[1]) * (v2[0] - v1[0]) - (v1[0] - v3[0]) * (v2[1] - v1[1])) / div;
if (ans.lambda >= 0.0f && ans.lambda <= 1.0f && ans.mu >= 0.0f && ans.mu <= 1.0f) {
if (ans.lambda == 0.0f || ans.lambda == 1.0f || ans.mu == 0.0f || ans.mu == 1.0f) {
ans.kind = float2::isect_result::LINE_LINE_EXACT;
}
else {
ans.kind = float2::isect_result::LINE_LINE_CROSS;
}
}
else {
ans.kind = float2::isect_result::LINE_LINE_NONE;
}
}
return ans;
}
double2::isect_result double2::isect_seg_seg(const double2 &v1,
const double2 &v2,
const double2 &v3,
const double2 &v4)
{
double2::isect_result ans;
double div = (v2[0] - v1[0]) * (v4[1] - v3[1]) - (v2[1] - v1[1]) * (v4[0] - v3[0]);
if (div == 0.0) {
ans.lambda = 0.0;
ans.kind = double2::isect_result::LINE_LINE_COLINEAR;
}
else {
ans.lambda = ((v1[1] - v3[1]) * (v4[0] - v3[0]) - (v1[0] - v3[0]) * (v4[1] - v3[1])) / div;
double mu = ((v1[1] - v3[1]) * (v2[0] - v1[0]) - (v1[0] - v3[0]) * (v2[1] - v1[1])) / div;
if (ans.lambda >= 0.0 && ans.lambda <= 1.0 && mu >= 0.0 && mu <= 1.0) {
if (ans.lambda == 0.0 || ans.lambda == 1.0 || mu == 0.0 || mu == 1.0) {
ans.kind = double2::isect_result::LINE_LINE_EXACT;
}
else {
ans.kind = double2::isect_result::LINE_LINE_CROSS;
}
}
else {
ans.kind = double2::isect_result::LINE_LINE_NONE;
}
}
return ans;
}
#ifdef WITH_GMP
mpq2::isect_result mpq2::isect_seg_seg(const mpq2 &v1,
const mpq2 &v2,
const mpq2 &v3,
const mpq2 &v4)
{
mpq2::isect_result ans;
mpq_class div = (v2[0] - v1[0]) * (v4[1] - v3[1]) - (v2[1] - v1[1]) * (v4[0] - v3[0]);
if (div == 0.0) {
ans.lambda = 0.0;
ans.kind = mpq2::isect_result::LINE_LINE_COLINEAR;
}
else {
ans.lambda = ((v1[1] - v3[1]) * (v4[0] - v3[0]) - (v1[0] - v3[0]) * (v4[1] - v3[1])) / div;
/* Avoid dividing mu by div: it is expensive in multi-precision. */
mpq_class mudiv = ((v1[1] - v3[1]) * (v2[0] - v1[0]) - (v1[0] - v3[0]) * (v2[1] - v1[1]));
if (ans.lambda >= 0 && ans.lambda <= 1 &&
((div > 0 && mudiv >= 0 && mudiv <= div) || (div < 0 && mudiv <= 0 && mudiv >= div))) {
if (ans.lambda == 0 || ans.lambda == 1 || mudiv == 0 || mudiv == div) {
ans.kind = mpq2::isect_result::LINE_LINE_EXACT;
}
else {
ans.kind = mpq2::isect_result::LINE_LINE_CROSS;
}
}
else {
ans.kind = mpq2::isect_result::LINE_LINE_NONE;
}
}
return ans;
}
#endif
double3 double3::cross_poly(Span<double3> poly)
{
/* Newell's Method. */
int nv = static_cast<int>(poly.size());
if (nv < 3) {
return double3(0, 0, 0);
}
const double3 *v_prev = &poly[nv - 1];
const double3 *v_curr = &poly[0];
double3 n(0, 0, 0);
for (int i = 0; i < nv;) {
n[0] = n[0] + ((*v_prev)[1] - (*v_curr)[1]) * ((*v_prev)[2] + (*v_curr)[2]);
n[1] = n[1] + ((*v_prev)[2] - (*v_curr)[2]) * ((*v_prev)[0] + (*v_curr)[0]);
n[2] = n[2] + ((*v_prev)[0] - (*v_curr)[0]) * ((*v_prev)[1] + (*v_curr)[1]);
v_prev = v_curr;
++i;
if (i < nv) {
v_curr = &poly[i];
}
}
return n;
}
#ifdef WITH_GMP
mpq3 mpq3::cross_poly(Span<mpq3> poly)
{
/* Newell's Method. */
int nv = static_cast<int>(poly.size());
if (nv < 3) {
return mpq3(0);
}
const mpq3 *v_prev = &poly[nv - 1];
const mpq3 *v_curr = &poly[0];
mpq3 n(0);
for (int i = 0; i < nv;) {
n[0] = n[0] + ((*v_prev)[1] - (*v_curr)[1]) * ((*v_prev)[2] + (*v_curr)[2]);
n[1] = n[1] + ((*v_prev)[2] - (*v_curr)[2]) * ((*v_prev)[0] + (*v_curr)[0]);
n[2] = n[2] + ((*v_prev)[0] - (*v_curr)[0]) * ((*v_prev)[1] + (*v_curr)[1]);
v_prev = v_curr;
++i;
if (i < nv) {
v_curr = &poly[i];
}
}
return n;
}
uint64_t hash_mpq_class(const mpq_class &value)
{
/* TODO: better/faster implementation of this. */
return get_default_hash(static_cast<float>(value.get_d()));
}
uint64_t mpq2::hash() const
{
uint64_t hashx = hash_mpq_class(this->x);
uint64_t hashy = hash_mpq_class(this->y);
return hashx ^ (hashy * 33);
}
uint64_t mpq3::hash() const
{
uint64_t hashx = hash_mpq_class(this->x);
uint64_t hashy = hash_mpq_class(this->y);
uint64_t hashz = hash_mpq_class(this->z);
return hashx ^ (hashy * 33) ^ (hashz * 33 * 37);
}
#endif
} // namespace blender