Rockbox Technical Forums

Support and General Use => Theming and Appearance Customization => Topic started by: GodEater on February 19, 2007, 08:31:25 AM

Title: Help with The GIMP
Post by: GodEater on February 19, 2007, 08:31:25 AM
Ok, I've been battling with The GIMP's frustrating helpfulness all morning and got nowhere, so I need some help now :

I'm trying to create a theme which uses a progress bar like this :
(http://www.rockbox.org/twiki/pub/Main/PastedImagesForFourms/pb_sample.png)

The little green circles are the only bit of the progress bar I want drawn - so I need to make the background transparent. The trouble with that is that when I render them on the background color that RB uses for transparency, I end up with an image like this :
(http://www.rockbox.org/twiki/pub/Main/PastedImagesForFourms/pb_sample_trans.png)

And that ends up displaying similarly to this :
(http://www.rockbox.org/twiki/pub/Main/PastedImagesForFourms/pb_sample_actual.png)

The problem here is the GIMP is trying to help me and anti-alias my pasted green circles onto the magenta background - but then I end up with some pixels which are mostly magenta, but not quite the one RB uses for transparency, so they end up being drawn like on the WPS. I've tried pasting the green circles over a white layer on top of the magenta layer so the anti-aliasing uses the white to mix with the green, and then removing the white background (or just switching it off prior to save). However as soon as I do this, The GIMP redoes the anti-aliasing with the magenta background again.

Now in case anyone is wondering the background my progress bar is going to be drawn over is *mostly* white, but not quite - otherwise I'd just do this with a solid background and not give myself all this pain.

So now - does anyone know The GIMP's foibles well enough to help me achieve what I'm after here ?
Title: Re: Help with The GIMP
Post by: Yotto on February 19, 2007, 12:53:11 PM
You have 3 problems here, and 2 of them are with Gimp :)

1) Make sure Opacity is 100%, Threshold is 0%, and Mode is "Normal" in the little tool area below where you pick your brushes.
2) If that doesn't do it, look through the menus for color options. I don't know what the setting is exactly, and don't think it'll matter as my Gimp doesn't have the described problem with your image unless I fiddle with the settings in #1.
3) Your circles aren't totally green.  Unless you place them on a light, or white, background, they'll still look funny when you get the magenta right.  My suggestion:  Finish the background in that area, cut that background out, and then paste your green circles onto THAT.  That way, it'll look exactly as you intend.
Title: Re: Help with The GIMP
Post by: saratoga on February 19, 2007, 12:56:51 PM
FWIW, if you're running Windows, you could always try Paint.Net.  Its free, open source, and the new 2.0 release is actually really nice to use.
Title: Re: Help with The GIMP
Post by: GodEater on February 19, 2007, 01:02:26 PM
@Yotta: Thanks, but I already sorted out how to do it with the help of a few people in #rockbox. I was simply trying to be too fancy - the secret is not to use layers at all. Just paint the green circles over a white background, and then fill in the white with the "fill" tool (oddly enough ;) ) with the Fill Similar Colors threshold down at zero (which is probably what you meant).

FWIW, the background is nearly white all the way across, so I don't need to do the background as you suggested.

@Saratoga: Linux only I'm afraid, but thanks for the suggestion.
Title: Re: Help with The GIMP
Post by: Yotto on February 19, 2007, 06:31:21 PM
Cool, glad you're all set.  I didn't know you were using layers, I would have suggested that first :)