How to get touched node center position on Sprite Kit? - position

Question

I am using Sprite Kit in Xcode and having problem with position.
I want to drag the node and drop to target area.If not the right target than send the node back to old position.
My code is working but when I touch node (except the center of node) anywhere will be holding center point of old position.So if target is wrong the node going back as little moved because of touched point was different than center of node.
Therefore If I can get center position of touched node than I can send back with absolute position!
-(void)touchesBegan:(NSSet *)touches withEvent:(UIEvent *)event {
UITouch *touch = [touches anyObject];
CGPoint positionInScene = [touch locationInNode:self];
[self selectNodeForTouch:positionInScene];}
Than
- (void)touchesMoved:(NSSet *)touches withEvent:(UIEvent *)event {
UITouch *touch = [touches anyObject];
CGPoint positionInScene = [touch locationInNode:self];
CGPoint previousPosition = [touch previousLocationInNode:self];
CGPoint translation = CGPointMake(positionInScene.x - previousPosition.x, positionInScene.y - previousPosition.y);
[self panForTranslation:translation];
}
//
-(void)selectNodeForTouch:(CGPoint)touchLocation{
SKSpriteNode *touchedNode = (SKSpriteNode *)[self nodeAtPoint: touchLocation];
if (![_selectedNode isEqual:touchedNode.name]) {
_selectedNode =touchedNode;
if ((newPositionStone.x-28)<5 || (newPositionStone.x-28)>(5*(-1))){
NSLog(#"Great! you drop node to target ");
}
else{
NSLog(#"Didn't drop node to target");//Send back to old position
_selectedNode.position = oldPositionStone;
}
}}
Thanks in advance!

Answer 1

You need to store the object's position at the moment of touch so you can revert back to it if your drag destination fails.
Create a CGPoint variable in your #implementation like so:
#implementation MyScene
{
CGPoint objectStartPosition;
}
In the touchesBegan: set the object's current position:
objectStartPosition = newPositionStone.position;
Then in your touchesEnded: check if the node's destination is valid:
if(whatever x and y positions you need to check for in here)
{
// do whatever you need to
} else {
newPositionStone.position = objectStartPosition;
}

Answer 2

The only solution I founded fixing the node on specific position.
But wondering does Sprite Kit has method to find position of touched node?
Here is my solution
-(void)touchesBegan:(NSSet *)touches withEvent:(UIEvent *)event {
UITouch *touch = [touches anyObject];
CGPoint positionInScene = [touch locationInNode:self];
if (positionInScene.x>400.0 && positionInScene.x<430.0) {
//Fix the position to original
oldPositionStone.x = 414;
oldPositionStone.y = 25;
}
[self selectNodeForTouch:positionInScene];}
//Than
-(void)touchesEnded:(NSSet *)touches withEvent:(UIEvent *)event{
UITouch *touch = [touches anyObject];
CGPoint positionInScene = [touch locationInNode:self];
NSLog(#"Touches END %f %f",positionInScene.x,positionInScene.y);
if (positionInScene.x>15 && positionInScene.x<40) {
newPositionStone.x=28;
newPositionStone.y = 25;
if ([_selectedNode.name isEqualToString:#"stone"]) {
_selectedNode.position=newPositionStone;
}
}
else{
positionInScene = oldPositionStone;
_selectedNode.position = positionInScene;
}
[self selectNodeForTouch:positionInScene];}