Game Development Reference
In-Depth Information
2.
Add the following code to the beginning of the
touchesBegan:
method
in ERGScene:
UITouch *touch = [touches anyObject];
SKSpriteNode *touchedNode = (SKSpriteNode *)[self
nodeAtPoint:[touch locationInNode:self]];
if (touchedNode.name == playerName) {
ERGPlayer *player = (ERGPlayer *) touchedNode;
player.selected = YES;
return;
}
On the first line, we get the
touch object
from the
touches
set and then try to
find if it intersects any node. To do that, we call the
nodeAtPoint:
method and
provide the location of the touch by converting
touch
to the Sprite Kit coordinates
in the
locationInNode:
method. We want to ignore taps on the background itself,
so this is why we check to make sure the player was tapped.
If we tap the player, we set
selected
to
YES
so that the
touchesMoved:
method
knows that we are dragging the character sprite. After that, we call
return
to exit
the method, as after this return statement, we have other code that we don't want
to trigger.
The next thing that we need to handle is the
touchesMoved:
method. We haven't
used that before, so type it as follows:
-(void)touchesMoved:(NSSet *)touches withEvent:(UIEvent *)event
{
UITouch *touch = [touches anyObject];
ERGPlayer *player = (ERGPlayer *)[self
childNodeWithName:playerName];
if (player.selected) {
player.position = [touch locationInNode:self];
}
}
This method (
touchesMoved:
) checks if the player is actually selected, and if it
is, the coordinates are changed to the touch location. We only want to drag the
character sprite if touches began on it.
