Sprite is not moving in proper position based on where user taps - ios

Question

It seems when I click to go right or left, the sprite does as intended. However when I click to the bottom in hopes it goes down, it actually goes up. And when I do the same thing vice versa, it goes down. I simply just want to make it so the user can navigate the sprite around properly depending where they touch on the screen.
Code:
- (void)setCenterOfScreen:(CGPoint) position {
CGSize screenSize = [[CCDirector sharedDirector] viewSize];
int x = MAX(position.x, screenSize.width/2);
int y = MAX(position.y, screenSize.height/2);
x = MIN(x, theMap.mapSize.width * theMap.tileSize.width - screenSize.width/2);
y = MIN(y, theMap.mapSize.height * theMap.tileSize.height - screenSize.height/2);
CGPoint goodPoint = ccp(x,y);
CGPoint centerOfScreen = ccp(screenSize.width/2, screenSize.height/2);
CGPoint difference = ccpSub(centerOfScreen, goodPoint);
self.position = difference;
}
- (void) setPlayerPosition:(CGPoint)position
{
mainChar.position = position;
}
-(void) touchEnded:(UITouch *)touch withEvent:(UIEvent *)event
{
CGPoint touchLoc = [touch locationInNode:self];
touchLoc = [[CCDirector sharedDirector] convertToGL:touchLoc];
touchLoc = [self convertToNodeSpace:touchLoc];
CGPoint playerPos = mainChar.position;
CGPoint diff = ccpSub(touchLoc, playerPos);
// Move horizontal or vertical?
if (abs(diff.x) > abs(diff.y))
{
if (diff.x > 0)
{
playerPos.x += theMap.tileSize.width;
}
else
{
playerPos.x -= theMap.tileSize.width;
}
}
else
{
if (diff.y > 0)
{
playerPos.y += theMap.tileSize.height;
}
else
{
playerPos.y -= theMap.tileSize.height;
}
}
if (playerPos.x <= (theMap.mapSize.width * theMap.tileSize.width) &&
playerPos.y <= (theMap.mapSize.height * theMap.tileSize.height) &&
playerPos.y >= 0 &&
playerPos.x >= 0)
{
[self setPlayerPosition:playerPos];
}
[self setCenterOfScreen:mainChar.position];
}

Answer 1

What is moving up that should be moving down? Is it the sprite or the layer? If it is the layer and is caused by your setCenterOfScreen method then...
Where you have:
CGPoint difference = ccpSub(centerOfScreen, goodPoint);
Try:
CGPoint difference = ccpSub(goodPoint, centerOfScreen);
Just to make it easy to visualize, image the Y of centerOfScreen is 10 and the goodPoint is 5 (meaning the touch is under the center). 10 - 5 = 5. So if you are adding that delta to the layer's/scene's current Y which starts at 0 initially, it will go up and not down like you're expecting since you just essentially made the Y = 5, which moves everything up and not down. Switch them around.
Update (Edited Answer):
Based on your comment, the issue is the player. Are you using cocos v3? Why don't you just have:
CGPoint touchLoc = [touch locationInNode:self];
And leave it at that? Back in versions like v2 I would have done something like:
-(void) ccTouchesBegan:(NSSet *)touches withEvent:(UIEvent *)event
{
UITouch* touch = [touches anyObject];
CGPoint touchPos = [touch locationInView:[touch view]];
touchPos = [[CCDirector sharedDirector] convertToGL:touchPos];
// Do somthing...
}
But in v3 you wouldn't do that. The method locationInNode looks like this...
- (CGPoint) locationInNode:(CCNode*) node
{
CCDirector* dir = [CCDirector sharedDirector];
CGPoint touchLocation = [self locationInView: [self view]];
touchLocation = [dir convertToGL: touchLocation];
return [node convertToNodeSpace:touchLocation];
}
So what you are doing is screwing up the values when you call the convertToGL and convertToNodeSpace methods again after it was already called in locationInNode. locationInNode already does that work for you.
The answer to your problem, remove:
touchLoc = [[CCDirector sharedDirector] convertToGL:touchLoc];
touchLoc = [self convertToNodeSpace:touchLoc];
Hope this helps.

Answer 2

The obvious solution would be to invert the signal when updating the y:
if (diff.y > 0)
playerPos.y -= theMap.tileSize.height;
else
playerPos.y += theMap.tileSize.height;
You can also change the reference of the position of the mainChar:
mainChar.positionType = CCPositionTypeMake(CCPositionUnitPoints, CCPositionUnitPoints, CCPositionReferenceCornerTopLeft);
or
mainChar.positionType = CCPositionTypeMake(CCPositionUnitPoints, CCPositionUnitPoints, CCPositionReferenceCornerBottomLeft);
Depending of the current reference.