cocos2d-iphone - Shooting bullets with a joystick cocos2d

Question

I have a working joystick in my cocos2d app but I cannot figure out how to make the 'player' shoot bullets out of it in the direction the joystick is pointing. I have the player moving and rotating. Also the bullets need to disappear when they hit the edges of the screen. Any help would be great. Thanks in advance.

Answer 1

您应该从操纵杆获得角度。例如，SneakyInput 有一个 degree 属性，可以让您像这样旋转子弹：
_bullet.rotation = -joystick.degrees;

你的更新方法可以是这样的：

void update:(ccTime) delta
{
    float moveAngle = _bullet.rotation;
    CGPoint deltaPos = CGPointMake(cos(moveAngle) * velocity, sin(moveAngle) * velocity);
    _bullet.position = ccpAdd(self.position, deltaPos);
}