Question

I feel that the best way to grasp a new programming language is to make simple games.

So for my first game setup, there will only be 4 buttons (Up, Down, Left, and Right). The buttons will change the position of a single image view object. So for example, if I wanted to press Up then the object will move up by having its X Y coordinates changed. This is where I’m stuck, how do I do this?

Here’s my psuedocode:

_imgShip.frame.position.x += 1;

That line of code is inside a button press event handler so if I press Right then the value of the current X coordinate will add 1 to itself. How do I do this exactly?

Answer 1

You’re pretty close. You’re probably better off moving the center though.

_imgShip.center = CGPointMake(_imgShip.center.x + 1.0, _imgShip.center.y);

Update:
I should also note that you could translate the view. This is a bit different but opens the door to rotations and scales too which could be useful for games 🙂

_imgShip.transform = CGAffineTransformMakeTranslation(1.0, 0.0);

For starting transforms use the Make variations. But there are also ones that build on each other so if you wanted to rotate AND translate you could do something like:

_imgShip.transform = CGAffineTransformMakeTranslation(1.0, 0.0);
_imgShip.transform = CGAffineTransformRotate(_imgShip.transform, 0.785); // in radians