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/* ScummVM - Graphic Adventure Engine
*
* ScummVM 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 3 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, see <http://www.gnu.org/licenses/>.
*
*/
#include "math/ray.h"
#include "common/util.h"
namespace Math {
Ray::Ray() {
}
Ray::Ray(const Vector3d &origin, const Vector3d &direction) :
_origin(origin),
_direction(direction) {
}
void Ray::transform(const Matrix4 &matrix) {
matrix.transform(&_origin, true);
matrix.transform(&_direction, false);
_direction.normalize();
}
void Ray::rotate(const Quaternion &rot) {
rot.transform(_origin);
rot.transform(_direction);
_direction.normalize();
}
void Ray::rotateDirection(const Quaternion &rot) {
rot.transform(_direction);
_direction.normalize();
}
void Ray::translate(const Vector3d &v) {
_origin += v;
}
bool Ray::intersectAABB(const AABB &aabb) const {
Vector3d dirFrac;
dirFrac.x() = 1.0f / _direction.x();
dirFrac.y() = 1.0f / _direction.y();
dirFrac.z() = 1.0f / _direction.z();
float t1 = (aabb.getMin().x() - _origin.x()) * dirFrac.x();
float t2 = (aabb.getMax().x() - _origin.x()) * dirFrac.x();
float t3 = (aabb.getMin().y() - _origin.y()) * dirFrac.y();
float t4 = (aabb.getMax().y() - _origin.y()) * dirFrac.y();
float t5 = (aabb.getMin().z() - _origin.z()) * dirFrac.z();
float t6 = (aabb.getMax().z() - _origin.z()) * dirFrac.z();
float tMin = MAX(MAX(MIN(t1, t2), MIN(t3, t4)), MIN(t5, t6));
float tMax = MIN(MIN(MAX(t1, t2), MAX(t3, t4)), MAX(t5, t6));
// If tMax < 0, the ray is intersecting the AABB, but the whole AABB is in the opposite direction
if (tMax < 0) {
return false;
}
// If tMin > tMax, the ray doesn't intersect the AABB
if (tMin > tMax) {
return false;
}
return true;
}
// Algorithm adapted from https://www.lighthouse3d.com/tutorials/maths/ray-triangle-intersection/
bool Ray::intersectTriangle(const Vector3d &v0, const Vector3d &v1,
const Vector3d &v2, Vector3d &vout, float &fout) const {
const Vector3d e1 = v1 - v0;
const Vector3d e2 = v2 - v0;
const Vector3d h = Vector3d::crossProduct(_direction, e2);
float a = e1.dotProduct(h);
if (fabs(a) < 1e-6f)
return false;
float f = 1.0f / a;
const Vector3d s = _origin - v0;
float u = f * s.dotProduct(h);
if (u < 0.0f || u > 1.0f)
return false;
const Vector3d q = Vector3d::crossProduct(s, e1);
float v = f * _direction.dotProduct(q);
if (v < 0.0f || u + v > 1.0f)
return false;
float t = f * e2.dotProduct(q);
if (t < 1e-6f)
return false;
fout = t;
vout = _origin + t * _direction;
return true;
}
}
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