firemonkey: do we need to use multi-res Bitmap?

Question

Under delphi, we have multi-res bitmap for Timage or Tglyph. this mean that we can gave several bitmap for several screen scale.

Exemple with a screen scale of 1 i will gave a bitmap of 100x100, for the screen scale of 1.5 i will gave a bitmap of 150*150, etc..

so taking care that most screen scale are 1, 1.5, 2, 3, and 4 we must provide 4 pictures. In 99.9999 % of the case the developer will simply do a normal resize of the image (under photoshop or similar app) in the 5 of fewer screen scale (seriously is their any developer who will gave radically different image between scale 1 and scale n ?)

But the resize algo to resize picture is quite powerful and often negligible. So if we gave only one bitmap (at the most biggest scale, 4) it's must be good/powerfull and it's will reduce also the size of the app.

also from smartphone to tablet i notice that to keep a good ratio i must increase all the font size, and image by 15%. So using multires bitmap and if i want to avoid any resize (the purpose of multires bitmap as i understand) i must have 10 bitmaps per image !!

So what are the advantage of multires bitmap? did i miss something or can i safely ignore multi-res bitmap ?

Answer 1

You don't have to, but you may want to. It depends on how good you want your app to look. Higher res images will make your image look better on higher resolution screens. I've found it especially important to use multi-res images on iOS applications -- iOS doesn't seem to scale bitmaps very well sometimes, so I provide 2 versions of each image, a lower res one for the phone, and a higher res one for a tablet (iPad).