You should do this using a three-level view hierarchy:
- top-level view
- scaled view
- sprite view 0
- sprite view 1
- sprite view 2
- etc.
- scaled view
Set the bounds of the scaled view to encompass the frames of all of the sprite views. Then set the transform of the scaled view so that it fits in the top-level view.
- (void)updateBoundsAndTransformOfView:(UIView *)scaledView {
CGRect scaledBounds = CGRectNull;
for (UIView *spriteView in scaledView.subviews) {
scaledBounds = CGRectUnion(scaledBounds, spriteView.frame);
}
scaledView.bounds = scaledBounds;
// Now scaledView's size is large enough to contain all of its subviews,
// and scaledView's coordinate system origin is at the left edge of the
// leftmost sprite and the top edge of the topmost sprite.
UIView *topLevelView = scaledView.superview;
CGRect topLevelBounds = topLevelView.bounds;
CGFloat xScale =topLevelBounds.size.width / scaledBounds.size.width;
CGFloat yScale = topLevelBounds.size.height / scaledBounds.size.height;
CGFloat scale = MIN(xScale, yScale);
scaledView.transform = CGAffineTransformMakeScale(scale, scale);
scaledView.center = CGPointMake(CGRectGetMidX(topLevelBounds), CGRectGetMidY(topLevelBounds));
}