paysages3d/src/basics/CappedCylinder.cpp

#include "CappedCylinder.h"

#include "Vector3.h"
#include "PackStream.h"

CappedCylinder::CappedCylinder(const Vector3 &base, const Vector3 &direction, double radius, double length)
    : InfiniteCylinder(InfiniteRay(base, direction), radius), length(length),
      container(base.add(direction.scale(length * 0.5)), length * 0.5) {
}

int CappedCylinder::findRayIntersection(const InfiniteRay &ray, Vector3 *first_intersection,
                                        Vector3 *second_intersection) const {
    if (not container.checkRayIntersection(ray)) {
        // We don't hit the containing sphere at all
        return 0;
    } else {
        // TODO Apply the caps
        int count = InfiniteCylinder::findRayIntersection(ray, first_intersection, second_intersection);

        if (count == 0) {
            return 0;
        } else if (count == 2) {
            if (checkPointProjection(first_intersection)) {
                if (checkPointProjection(second_intersection)) {
                    return 2;
                } else {
                    return 1;
                }
            } else {
                if (checkPointProjection(second_intersection)) {
                    *first_intersection = *second_intersection;
                    return 1;
                } else {
                    return 0;
                }
            }
        } else {
            // count == 1
            if (checkPointProjection(first_intersection)) {
                return 1;
            } else {
                return 0;
            }
        }
    }
}

bool CappedCylinder::checkPointProjection(Vector3 *point) const {
    double proj_length = axis.getDirection().dotProduct(point->sub(axis.getOrigin()));
    return 0.0 <= proj_length && proj_length <= length;
}

void CappedCylinder::save(PackStream *stream) const {
    InfiniteCylinder::save(stream);
    stream->write(&length);
}

void CappedCylinder::load(PackStream *stream) {
    InfiniteCylinder::load(stream);
    stream->read(&length);
}