Grid the landscape, and shortcircuit checks on the collision array if there are no nearby checked in collisions to be collided with. This is a big win for fire's ammoshove in particular. Also add a +2 that seemed missing in the check, and update fire accordingly.
#include <QScrollArea>
#include <QMainWindow>
#include <QLabel>
#include <QListWidget>
#include <QPushButton>
#include "pixlabel.h"
class MyWindow : public QMainWindow
{
Q_OBJECT
public:
MyWindow(QWidget * parent = 0, Qt::WFlags flags = 0);
private:
QScrollArea * sa_xy;
PixLabel * xy;
QPushButton * buttAdd;
QPushButton * buttCode;
QPushButton * buttSave;
QPushButton * buttLoad;
private slots:
void Code();
void Save();
void Load();
};