////  SphereShape.cpp//  libraries/shared/src////  Created by Andrew Meadows on 2014.06.17//  Copyright 2014 High Fidelity, Inc.////  Distributed under the Apache License, Version 2.0.//  See the accompanying file LICENSE or http://www.apache.org/licenses/LICENSE-2.0.html// #include <glm/gtx/norm.hpp> #include "SphereShape.h" bool SphereShape::findRayIntersection(RayIntersectionInfo& intersection) const {    float r2 = _boundingRadius * _boundingRadius;     // compute closest approach (CA)    float a = glm::dot(_translation - intersection._rayStart, intersection._rayDirection); // a = distance from ray-start to CA    float b2 = glm::distance2(_translation, intersection._rayStart + a * intersection._rayDirection); // b2 = squared distance from sphere-center to CA    if (b2 > r2) {        // ray does not hit sphere        return false;    }    float c = sqrtf(r2 - b2); // c = distance from CA to sphere surface along intersection._rayDirection    float d2 = glm::distance2(intersection._rayStart, _translation); // d2 = squared distance from sphere-center to ray-start    float distance = FLT_MAX;    if (a < 0.0f) {        // ray points away from sphere-center        if (d2 > r2) {            // ray starts outside sphere            return false;        }        // ray starts inside sphere        distance = c + a;    } else if (d2 > r2) {        // ray starts outside sphere        distance = a - c;    } else {        // ray starts inside sphere        distance = a + c;    }    if (distance > 0.0f && distance < intersection._rayLength && distance < intersection._hitDistance) {        intersection._hitDistance = distance;        intersection._hitNormal = glm::normalize(intersection._rayStart + distance * intersection._rayDirection - _translation);        intersection._hitShape = const_cast<SphereShape*>(this);        return true;    }    return false;}