Overlaid icons appear jagged with "Use large icons"

[Dzondu]

OS: WinXP, SP3

Steps to reproduce:

1. Use a custom icon theme for Total Commander.
Not really sure if it happens on all, or just some of the icon themes.
I tried it on two versions of the Gant theme, one downloaded from totalcommanderDOTnet, and the othera version I converted to work on vista 64.

2. Enable the "Use large icons" effect (Display Properties -> Appearance -> Effects -> Use large icons").

Result:
Icons with overlays appear jagged or pixelated. As if commander used a smaller icon, and streched it to it's current size.
(Note that SVN's overlay seems to be somewhat smaller, while windows' share overlay stays (or, rather, appears) the same)

[Edit:] As this is my first post, I can't attach relevant screenshots.
Will attempt to, later in thread...

[ghisler(Author)]

This is normal, because TC has to resize the overlay icons by itself. Windows doesn't support overlay icons of arbitrary size.

[Dzondu]

Hm, I'm not sure if I managed to get my message across.
I'll just blame it on the lack of a proper screenshot.

My grievence here is not with the size of the actual overlay (though I'm not quite sure why it would need to be resized), it with the actual underlying folder icon.


[Edit]
Finally, the screenshot, with the jagged icons on the right:
http://i21.photobucket.com/albums/b300/nikrifle/Bug.png

Note how the normal folder icon stays the same.

[ghisler(Author)]

Well, TC has to draw the underlying icon at the size of the overlay, then draw the overlay on top, and finally resample the entire image to the required size. The overlay itself cannot be resampled because then the transparency would be lost.

[Dzondu]

Well, TC has to draw the underlying icon at the size of the overlay, then draw the overlay on top, and finally resample the entire image to the required size.

Is there no way around this?

If I understood correctly, you have access to the actual overlay .ico file, right? Couldn't one just choose the appropriate size from it and draw it on top of the regular-sized underlying icon? (assuming it is a multi-resolution .ico)

The overlay itself cannot be resampled because then the transparency would be lost.

This seems weird.
If I follow, the actual process looks like this:
1. "Draw the underlying icon at the size of the overlay" (resampling upwards, no loss of transparency)
2. Draw the overlay on top
3. Resample the entire image to the required size. (again, no loss of transparency)

Is there really no way of resizing the overlay itself, even though we CAN resize the final icon?

Again, if possible, the first solution (just choosing an appropriate size for the overlay and drawing it over the original icon) would be preffered, but surely there must be some way of resizing the overlay without loss of transparency. Is the accessible overlay in .ico format?

[ghisler(Author)]

The problem is the possible semi-transparence of these overlays. That's why they cannot simply be resampled.

[Dzondu]

Ok, than, how about the other thing I mentioned; i.e. instead of getting the overlay at the size windows is drawing it (as it has no real relevance to TC), trying to get the size that is closest to the one the user needs.

Now, I'm mentioning this assuming the overlay is available to us as a windows icon. As such, it would contain different sizes of the same image, allowing one to use whichever is most suited at the time.
In the example above, instead of resampling the overlays and folder icons, TC would simply use NormalIcon.ico's 32x32 resolution (or whatever icon size the user chose) and paste it on a regular folder icon.
TortoiseSVN' icons, for instance, contain 16x16, 32x32 and 48x48 resolutioned versions, so, as far as those are concerned, there would only be a need for resampling if the user chooses a really non-standard icon size.

Obviously, none of this can be done if we can't access the original overlay .ico, but just thougt I'd mention it, just in case.