Tower.cpp

/** @file Tower.cpp
@brief This file contains member function definitions for the Tower class.

Towers have an attack area and fire a projectile when an enemy gets within range.
*/

#include "Tower.h"
#include <QPixmap>
#include <QVector>
#include <QPointF>
#include <QPolygonF>
#include "Projectile.h"
#include <QPointF>
#include <QLineF>
#include "Game.h"
#include <QTimer>
#include <QGraphicsRectItem>
#include "Enemy.h"
#include <typeinfo>

extern Game* game;

#include <QDebug>
Tower::Tower(QGraphicsItem* parent):QObject(), QGraphicsPixmapItem(parent)
{

    // set the graphics
    //setPixmap(QPixmap(":/images/naruto.png"));


    // create points vector
    QVector<QPointF> points;
    points << QPoint(1,0) << QPoint(2,0) << QPoint(3,1) << QPoint(3,2) << QPoint(2,3)
               << QPoint(1,3) << QPoint(0,2) << QPoint(0,1);

    //scale points
    int SCALE_FACTOR=140;
    for (size_t i = 0, n = points.size(); i<n; ++i){
        points[i] *= SCALE_FACTOR;
    }

    //create a polygon from these points
    QPolygonF polygon(points);

    //create the QGraphicsPolygonItem
    attack_area = new QGraphicsPolygonItem(QPolygonF(points),this);
    attack_area->setPen(QPen(Qt::DotLine));

    //move the polygon
    QPointF poly_center(1.5,1.5);
    poly_center *= SCALE_FACTOR;
    poly_center = mapToScene(poly_center);;
    QPointF tower_center(x()+40,y()+50);
    QLineF ln(poly_center,tower_center);
    attack_area->setPos(x()+ln.dx(),y()+ln.dy());

    // set attack_dest
    attack_dest = QPointF(0,0);
    has_target = false;
}

double Tower::distanceTo(QGraphicsItem *item)
{
    //QLineF ln(pos(), item->pos());
    QLineF ln(this->pos(),item->pos());

    return ln.length();
}

void Tower::fire(){
    Projectile * projectile = new Projectile();
    projectile->setPos(x()+40,y()+50);

    QLineF ln(QPointF(x()+40,y()+50),attack_dest);
    int angle = -1 * ln.angle();

    projectile->setRotation(angle);
    game->scene->addItem(projectile);
}

void Tower::aquire_target(){

    // get a list of all items colliding with attack_area
    QList<QGraphicsItem *> colliding_items = attack_area->collidingItems();

    // assume tower does not have a target, unless we find one
    has_target = false;


    // find the closest Enemy
    double closest_dist = 300;
    QPointF closest_pt(0,0);
    for (size_t i = 0, n = colliding_items.size(); i < n; ++i){

        // make sure it is an enemy
        Enemy * enemy = dynamic_cast<Enemy *>(colliding_items[i]);

        // see if distance is closer
        if (enemy){
            double this_dist = distanceTo(colliding_items[i]);
            if (this_dist < closest_dist){
                closest_dist = this_dist;
                closest_pt = colliding_items[i]->pos();
                has_target = true;
            }
        }
    }

    /*
    if (colliding_items.size() == 1){
        has_target = false;
        return;
    }

    double closest_dist = 300;
    QPointF closest_pt = QPointF(0,0);
    for (size_t i = 0, n = colliding_items.size(); i < n; i++){
        Enemy * enemy = dynamic_cast<Enemy *>(colliding_items[i]);
        if (enemy){
            double this_dist = distanceTo(enemy);
            if (this_dist < closest_dist){
                closest_dist = this_dist;
                closest_pt = colliding_items[i]->pos();
                has_target = true;
            }
        }
    }
    */

    // if has target, set the closest enemy as the attack_dest, and fire
    if (has_target){
        attack_dest = closest_pt;
        fire();
    }

}