I am working on a tower defence game and trying to shoot a projectile from a turret. The sprite of the turret I have looks like this
Also, the bullet looks like this
What I want to do is make the turret shot the bullet to a certain point (for example [code]attackDestination = QPointF(1000, 500);[/code]
for this, I have a class Bullet, with the slot move, connected to a QTimer:
[code]
void Bullet::move()
{
int stepSize = 20; // how fast the bullet moves
double angle = rotation();
double dy = stepSize * qSin(qDegreesToRadians(angle)); // The X that needs to be moved
double dx = stepSize * qCos(qDegreesToRadians(angle)); // The Y that needs to be moved
setPos(x() + dx, y() + dy);
}
[/code]
I also have a slot in the Tower class (which stands for the turret)
void Tower::attackTarget()
{
Bullet *bullet = new Bullet();
//getWidthMap() returns the width of the tower
//getHeightMap() returns the height of the tower
bullet->setPos(x() + getWidthMap() /2, y());
QLineF line(QPointF(x() + getWidthMap() /2, y()), attackDestination);
double angle =(-1) * line.angle();
bullet->setRotation(angle);
this->setRotation(90 + angle);
game->scene->addItem(bullet);
}
I have rotated the turret by +90 degrees because its initial position is vertical and it needs to form an angle (that of the line with oX) just like the bullet. The rotation happens clockwise.
The problem is with the position of the bullet relative to the turret when attacking.
Without the line this->setRotation(90 + angle); (first picture), with it (second picture)
As you can see, the bullets are starting from the initial position of the turret (when it was not rotated), because the pos() function keeps the initial X and Y. How can I fix that ?
