Files
OpenSpace/src/util/collisionhelper.cpp
2021-08-15 19:34:10 +02:00

76 lines
3.6 KiB
C++

/*****************************************************************************************
* *
* OpenSpace *
* *
* Copyright (c) 2014-2021 *
* *
* Permission is hereby granted, free of charge, to any person obtaining a copy of this *
* software and associated documentation files (the "Software"), to deal in the Software *
* without restriction, including without limitation the rights to use, copy, modify, *
* merge, publish, distribute, sublicense, and/or sell copies of the Software, and to *
* permit persons to whom the Software is furnished to do so, subject to the following *
* conditions: *
* *
* The above copyright notice and this permission notice shall be included in all copies *
* or substantial portions of the Software. *
* *
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, *
* INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A *
* PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT *
* HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF *
* CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE *
* OR THE USE OR OTHER DEALINGS IN THE SOFTWARE. *
****************************************************************************************/
#include <openspace/util/collisionhelper.h>
namespace openspace::collision {
// Source: http://paulbourke.net/geometry/circlesphere/raysphere.c
bool lineSphereIntersection(glm::dvec3 p1, glm::dvec3 p2, glm::dvec3 center,
double r, glm::dvec3& intersectionPoint)
{
double a, b, c;
const glm::dvec3 diffp = p2 - p1;
a = diffp.x * diffp.x + diffp.y * diffp.y + diffp.z * diffp.z;
b = 2.0 * (diffp.x * (p1.x - center.x) + diffp.y * (p1.y - center.y) +
diffp.z * (p1.z - center.z));
c = center.x * center.x + center.y * center.y + center.z * center.z;
c += p1.x * p1.x + p1.y * p1.y + p1.z * p1.z;
c -= 2.0 * (center.x * p1.x + center.y * p1.y + center.z * p1.z);
c -= r * r;
double intersectionTest = b * b - 4.0 * a * c;
// No intersection
if (std::abs(a) < 0 || intersectionTest < 0.0) {
return false;
}
// Intersection
else {
// Only care about the first intersection point if we have two
const double t = static_cast<double>(
(-b - std::sqrt(intersectionTest)) / (2.0 * a)
);
// Check if utside of line segment between p1 and p2
if (t <= 0 || t >= 1.0) {
return false;
}
intersectionPoint = p1 + t * diffp;
return true;
}
}
bool isPointInsideSphere(const glm::dvec3& p, const glm::dvec3& c, double r) {
const glm::dvec3 v = c - p;
const double squaredDistance = v.x * v.x + v.y * v.y + v.z * v.z;
const double squaredRadius = r * r;
return (squaredDistance <= squaredRadius);
}
} // namespace openspace::collision