PlanetFleet/guidedMissile.cpp

#include <model.h>

#include "guidedMissile.h"
#include "unit.h"
#include "guidedMissileData.h"
#include "util.h"

using namespace vb01;
using namespace std;

namespace battleship{
    GuidedMissile::GuidedMissile(Unit *unit, Vector3 pos, Vector3 target, Vector3 dirVec, Vector3 leftVec, Vector3 upVec, int id, int weaponTypeId, int weaponId) :
    Projectile(unit, nullptr, pos, dirVec, leftVec, upVec, id, weaponTypeId, weaponId) {
        speed = .05;

        for (int i = 0; i < 180; i++)
            arcLength += speed * cos(turnAngle * i);

        this->target = target;
        Vector3 targVec = Vector3(target.x - initPos.x, 0, target.z - initPos.z);
        b = targVec.getLength() / 2;
        x = -b;
        dirVec = Vector3(0,1,0);
        upVec = -targVec.norm();
        leftVec = Quaternion(PI / 2, dirVec) * dirVec;
        rayLength = 3;
        damage = 100;
    }

    void GuidedMissile::update() {
        Projectile::update();
        updateVecs();
        node->setPosition(pos);
        checkForCollision();
    }

    void GuidedMissile::updateVecs() {
        if(x < b){
            Vector3 targVec = Vector3(target.x - initPos.x, 0, target.z - initPos.z);
            pos = pos + targVec.norm() * speed;
            x += speed;
            pos.y = sqrt(1. - x * x / (b * b)) * a;
            float tanAngle = atan(-a*x/(b*b*sqrt(1.-x*x/(b*b))));
            Quaternion rotQuat = Quaternion(tanAngle, leftVec);
            Vector3 dirProj = (dirVec == Vector3::VEC_J ? upVec : Vector3(dirVec.x, 0, dirVec.z).norm());
            orientProjectile(rotQuat * targVec);
        }
        else
            pos.y -= speed;
    }
}