Why does this only detect touches in the center of the CCSprites?

I am trying to let the finger drag CCSprite with the following code:

-(BOOL)ccTouchBegan:(UITouch *)touch withEvent:(UIEvent *)event {
    CGPoint location = [touch locationInView: [touch view]];
    CGPoint convertedCoordinate = [[CCDirector sharedDirector] convertToGL:location];

    CGRect redCircleRect = CGRectMake(redCircle.position.x, redCircle.position.y, redCircle.contentSize.width, redCircle.contentSize.height);
    CGRect redCircle2Rect = CGRectMake(redCircle2.position开发者_开发知识库.x, redCircle2.position.y, redCircle2.contentSize.width, redCircle2.contentSize.height);

    if(CGRectContainsPoint(redCircleRect, convertedCoordinate)) {
        //redCircle.position = ccp(convertedCoordinate.x, convertedCoordinate.y);
        NSLog(@"Touched");
        spriteIndex = 1;
    }
    else if(CGRectContainsPoint(redCircle2Rect, convertedCoordinate)) {
        //redCircle2.position = ccp(convertedCoordinate.x, convertedCoordinate.y);
        NSLog(@"Touched2");
        spriteIndex = 2;
    }
    else {
        spriteIndex = 0;
    }
    return YES;
}
-(void)ccTouchMoved:(UITouch *)touch withEvent:(UIEvent *)event {
    CGPoint location = [touch locationInView: [touch view]];
    CGPoint convertedCoordinate = [[CCDirector sharedDirector] convertToGL:location];   

    if (spriteIndex == 1) {
        redCircle.position = ccp(convertedCoordinate.x, convertedCoordinate.y);
    }
    else if (spriteIndex == 2) {
        redCircle2.position = ccp(convertedCoordinate.x, convertedCoordinate.y);
    }

    //CGRect RedCircleRect = CGRectMake(redCircle.position.x, redCircle.position.y, redCircle.contentSize.width, redCircle.contentSize.height);
    //CGRect RedCircle2Rect = CGRectMake(redCircle.position.x, redCircle.position.y, redCircle.contentSize.width, redCircle.contentSize.height);

}

My logic is as follows:

In ccTouchesBegan I get the location of the touch, convert it to the right coordinates, then make two CGRect's that are, supposedly, the same dimensions and location of the two sprites I have declared. Then, I check if the finger is touching one of those two rectangles using CGRectContainsPoint. In there, I have a global int called spriteIndex that I assign a value according to what circle was touched.

Next, in ccTouchesMoved I check if spriteIndex has been given the "index" of one of the two sprites I am trying to move, and if so, set the location of the sprite that is selected to the touch location.

The Problem:

This code only sort of works. It lets me drag the CCSprites, but only if I click the center. And the sprite is 40 by 40 pixels, so it is by no means small.

Found the answer on another forum:

CGRect redCircleRect = CGRectMake(redCircle.position.x, redCircle.position.y, redCircle.contentSize.width, redCircle.contentSize.height);
CGRect redCircle2Rect = CGRectMake(redCircle2.position.x, redCircle2.position.y, redCircle2.contentSize.width, redCircle2.contentSize.height);

should be:

CGRect redCircleRect = CGRectMake(redCircle.position.x-20.0, redCircle.position.y-20.0, 40.0, 40.0);
CGRect redCircle2Rect = CGRectMake(redCircle2.position.x-20.0, redCircle2.position.y-20.0, 40.0, 40.0);

This is because, the CGRect copies are being made from the center pointer where it should be made from the lower left.