How to set parameters on iPhone - ios

Question

Im sorry I wasn't sure of the terminology for this question but I hope you can understand and help me out. (Also if the terminology is wrong correct me for future reference..Thanks!)
I am trying to set parameters for my iOS game so that when you click either side of the screen the player will turn to that side.
The code I have works to make the player move although it is set to the whole screen therefore only goes in one direction...
-(void)touchesBegan:(NSSet *)touches withEvent:(UIEvent *)event{
X = -7;
Player.image = [UIImage imageNamed:#"Player Left.png"];
}
What needs to be added so that ONLY when the user touches the left side of the screen does this code run.
Thanks in advance and I hope you understand.
I am very sorry for any wrong terminology.

Answer 1

Check if touch point is in left side of screen.. e.g -
if ([touches count] == 1) {
// one finger
CGPoint touchPoint = [[touches anyObject] locationInView:self.view];
if (touchPoint.x <= [UIScreen mainScreen].bounds.size.width*0.50) {
Player.image = [UIImage imageNamed:#"Player Left.png"];
}else{
Player.image = [UIImage imageNamed:#"Player Right.png"];
}
}

Answer 2

Just define your "reactable" area by defining a CGRect. Then try to define if the touch is inside by using CGRectContainsPoint(). Something like that (not tested) :
CGRect reactable = CGRectMake(0, 0, 10, 10); // A square of 10 px
UITouch *touch = [[event allTouches] anyObject];
CGPoint touchLocation = [touch locationInView:self];
if (CGRectContainsPoint(reactable, touchLocation)
Player.image = [UIImage imageNamed:#"Player Left.png"];