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/* ResidualVM - A 3D game interpreter
*
* ResidualVM is the legal property of its developers, whose names
* are too numerous to list here. Please refer to the COPYRIGHT
* file distributed with this source distribution.
*
* 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.
*
*/
#include "math/line2d.h"
#include "math/rect2d.h"
namespace Math {
Line2d::Line2d() :
_a(0), _b(0), _c(0) {
}
Line2d::Line2d(const Vector2d &direction, const Vector2d &point) {
Vector2d d = direction;
if (fabsf(d.getX()) > 0.0001f) {
_a = d.getY() / d.getX();
_b = -1;
} else {
_a = 1;
_b = 0;
}
if (_b == 0) {
_c = -point.getX();
} else {
_c = point.getY() - (d.getY() / d.getX()) * point.getX();
}
}
Line2d Line2d::getPerpendicular(const Vector2d &point) const {
Vector2d v(1, _b / _a);
return Line2d(v, point);
}
Vector2d Line2d::getDirection() const {
return Vector2d(1, _a);
}
float Line2d::getDistanceTo(const Vector2d &point, Vector2d *intersection) const {
float dist = fabsf(_a * point.getX() + _b * point.getY() + _c) / sqrt(_a * _a + _b * _b);
if (intersection) {
intersectsLine(getPerpendicular(point), intersection);
}
return dist;
}
bool Line2d::intersectsLine(const Line2d &line, Vector2d *pos) const {
// if (*this == line) {
// return false;
// }
float a = _a;
float b = _b;
float c = _c;
float d = line._a;
float e = line._b;
float f = line._c;
float x, y;
const float det = a * e - b * d;
if (fabsf(det) < 0.0001f) {
return false;
}
x = (-c * e + b * f) / det;
y = (-a * f + c * d) / det;
if (pos)
*pos = Vector2d(x, y);
return true;
}
bool Line2d::containsPoint(const Vector2d &point) const {
float n = _a * point.getX() + _b * point.getY() + _c;
return (n < 0.0001 && n > -0.0001);
}
float Line2d::getYatX(float x) const {
return -(_a * x + _c) / _b;
}
Common::Debug &operator<<(Common::Debug &dbg, const Math::Line2d &line) {
if (fabsf(line._a) < 0.0001f) {
dbg.nospace() << "Line2d: <y = " << (-line._a / line._b) << " * x + " << -line._c / line._b << ">";
} else {
dbg.nospace() << "Line2d: <x = " << (-line._b / line._a) << " * y + " << -line._c / line._a << ">";
}
return dbg.space();
}
Segment2d::Segment2d() {
}
Segment2d::Segment2d(const Vector2d &b, const Vector2d &e) :
_begin(b), _end(e) {
}
Segment2d::Segment2d(const Segment2d &other) {
*this = other;
}
Vector2d Segment2d::begin() const {
return _begin;
}
Vector2d Segment2d::end() const {
return _end;
}
Vector2d Segment2d::middle() const {
return (_begin + _end) / 2.f;
}
Line2d Segment2d::getLine() const {
float y = _end.getY() - _begin.getY();
float x = _end.getX() - _begin.getX();
Vector2d v(x, y);
return Line2d(v, _begin);
}
Line2d Segment2d::getPerpendicular(const Vector2d &point) const {
return getLine().getPerpendicular(point);
}
bool Segment2d::intersectsSegment(const Segment2d &other, Vector2d *pos) {
float denom = ((other._end.getY() - other._begin.getY()) * (_end.getX() - _begin.getX())) -
((other._end.getX() - other._begin.getX()) * (_end.getY() - _begin.getY()));
float d = ((_end.getY() - _begin.getY()) * (other._end.getX() - other._begin.getX())) -
((_end.getX() - _begin.getX()) * (other._end.getY() - other._begin.getY()));
float nume_a = ((other._end.getX() - other._begin.getX()) * (_begin.getY() - other._begin.getY())) -
((other._end.getY() - other._begin.getY()) * (_begin.getX() - other._begin.getX()));
float nume_b = ((_end.getX() - _begin.getX()) * (other._begin.getY() - _begin.getY())) -
((_end.getY() - _begin.getY()) * (other._begin.getX() - _begin.getX()));
if (denom == 0.0f) {
return false;
}
float ua = nume_a / denom;
float ub = nume_b / d;
if (ua < 0 || ua > 1 || ub < 0 || ub > 1) {
return false;
}
// Get the intersection point.
if (pos)
*pos = _begin + (_end - _begin) * ua;
return true;
}
bool Segment2d::intersectsLine(const Line2d &line, Vector2d *pos) {
Vector2d p;
if (getLine().intersectsLine(line, &p) && containsPoint(p)) {
if (pos)
*pos = p;
return true;
}
return false;
}
bool Segment2d::containsPoint(const Vector2d &point) const {
if (getLine().containsPoint(point)) {
return Rect2d(_begin, _end).containsPoint(point);
}
return false;
}
Segment2d &Segment2d::operator=(const Segment2d &other) {
_begin = other._begin;
_end = other._end;
return *this;
}
}
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