NSImage with multiple representation sizes
NSImage with multiple representation sizes
- Subject: NSImage with multiple representation sizes
- From: Benjamin Rister <email@hidden>
- Date: Thu, 3 Sep 2009 14:00:35 -0400
(Apologies if this ends up a duplicate…I sent the original over a week
ago, and as far as I can see it's not in either Apple's or
Cocoabuilder's archives, so I don't see any other explanation besides
it just being eaten by something.)
The core question:
Is it still the best practice to have conceptually same images of
different sizes in different files, e.g. Foo9x9.tiff, Foo32x32.tiff?
icns isn't an option because they aren't all the standard icns sizes,
and several places in the docs seem to discourage lumping them
together (e.g. with tiffutil) anyway.
The details:
We have several images that are displayed at different sizes at
various places in an application. Our artist has generated several
bitmaps for these different scales. Modeling on the concept of
an .icns file, my inclination would be to try and lump them all
together in one multi-representation file and let NSImage figure out
what the best representation is to draw from at any given point. This
not only is convenient for the various usages around the app, but also
for resolution independence (...maybe...see below).
However, man tiffutil says:
-cat allows combining multiple TIFF files into one. ... If the real
sizes (pixel size
divided by dpi) of the images being combined are not the same,
a warning
will be generated. This makes sure that NSImage can
successfully choose
the right size image out of the generated TIFF file.
And Cocoa Drawing Guide: Images, "How an Image Representation Is
Chosen" gives rules about color space, dpi, and bit depth, but there's
no rule about choosing representations based on size. (But there's
icns, right? How is that supposed to work, then?)
I'm also concerned for resolution independence that the system might
not choose the 32x32px rep to fill a 16x16pt space at a 2x scale
factor, because everything I've seen in the resolution independence
docs only talks about representations with different dpi. It would be
rather inelegant to have to have multiple representations with the
same pixels and just different metadata.
So between the resolution independence concern, and the docs seemingly
discouraging having different sized images in one file, this raises
the core question above. What's the best way to arrange this for both
drawing the image at different sizes in different places and
resolution independence?
Best,
Benjamin Rister_______________________________________________
Cocoa-dev mailing list (email@hidden)
Please do not post admin requests or moderator comments to the list.
Contact the moderators at cocoa-dev-admins(at)lists.apple.com
Help/Unsubscribe/Update your Subscription:
This email sent to email@hidden