Added a new option. -0 (that's a zero) or --itrans will invoke the
immotile optimization for transparency, so named because it works best
on windows that don't move around much on the desktop. It works even
better for windows that are sticky between desktops. So if you have
logging windows (running tail -f and the like) that are shaded/tinted,
you definitely want to have this. It will even benefit ordinary Eterm
windows, provided you don't move them around a lot. Eterms that do
not change desktops may be better off with the other way; Eterms that
are not shaded or tinted at all will not behave any differently.
Here's the technical explanation for those who are interested. The
old (and still the default) behavior is for Eterm to check to see if
any color modifiers are applied to the image_bg class, and if so, to
make a copy of the *entire* desktop image which is then shaded/tinted
appropriately. It then snapshots a portion of that for the actual
background. This way, if the Eterm window is moved, all the shading
and tinting will have already been done, so all it has to do is grab
another portion of the desktop and use it. However, this involves a
LOT of calculations (one per pixel of the desktop pixmap) on startup
and at every desktop switch.
The immotile optimization is intended to reverse that logic by
optimizing for windows that do not move (hence the term "immotile").
It takes the snapshot of the desktop pixmap and applies any shading
or tinting *after* taking the portion it needs. This requires much
fewer calculations on startup and when changing desktops, but the
entire set of calculations must be repeated whenever the window is
moved. This is fine for small windows or windows that don't move
very often, but that's not always the case. So it is to your
advantage to pick one or the other depending on how you use each
particular theme or window.
Two notes. One, keep in mind that the -0/--itrans option doesn't
*activate* transparency; you still need -O/--trans for that. Two,
this does not affect Eterms with no color modifiers applied to the
background. In that case, Eterm still references the existing
desktop pixmap to save memory.
SVN revision: 2191
607268f595