Allow .gih image pipe brushes to provide a custom thumbnail (patch incl.)
Submitted by Tommy
Link to original bug (#561770)
Description
I've started designing GIMP brushes and am impressed with the flexibility available. However I've come across the problem that the only way to choose the brush thumbnail (the icon that appears in the brush chooser) and the brush outline at the cursor is to use one of the actual brush frames.
With some animated brushes the end result doesn't look much like any of the individual frames.
A simple example is a brush I just made which spatters dots around randomly when you draw with it. It uses a large centered spot as the brush thumbnail which is not a very good preview of what the brush does.
http://mesilliac.deviantart.com/art/Spatter-animated-GIMP-brush-104173139
I thought that a good way to allow making a custom brush thumbnail would be to allow the .gih file to specify an offset for the brushes inside it, so that the first x brushes will be ignored when drawing, but the initial brush in the file is still used as the thumbnail.
It was pretty straightforward so I made a patch that allows this.
It doesn't affect the current brushes at all, they just use the default offset of 0.
The patch is against GIMP version 2.6.1 as provided by Ubuntu, but I can make one against svn if needed.