Using AffineTransform for edge detection

@shipit wrote:

Basically I don't want the user to move/scale the sprite offscreen. For moving it's super easy, here's my working solution:

bool CoordsTest::onGesturePan(TGesturePan *gesture) {
    Vec2 delta = gesture->getTranslation();
    Rect contentRect = _contentNode->getBoundingBox();
    contentRect.origin += delta;

    if (contentRect.containsPoint(_screenMinPoint) && contentRect.containsPoint(_screenMaxPoint)) {
        _contentNode->setPosition(_contentNode->getPosition() + delta);
    }

    return true;
}

It works great! Here's another way I tried that isn't working and I want to figure this out in case I want to add scale/rotation operations:

bool CoordsTest::onGesturePan(TGesturePan *gesture) {
    Vec2 delta = gesture->getTranslation();
    Rect contentRect = _contentNode->getBoundingBox();
    
    AffineTransform transform = _contentNode->getNodeToWorldAffineTransform();
    transform = AffineTransformTranslate(transform, delta.x, delta.y);
    contentRect = RectApplyAffineTransform(contentRect, transform);

    if (contentRect.containsPoint(_screenMinPoint) && contentRect.containsPoint(_screenMaxPoint)) {
        _contentNode->setPosition(_contentNode->getPosition() + delta);
    }

    return true;
}

This does not work. I think my starting transform ie _contentNode->getNodeToWorldAffineTransform() maybe wrong.

help?! thx!

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