antialias problem when transforming an object in pattern

[v1nce]

12777 ubuntu 12.04

when a path is transformed into a pattern this pattern suffers from "aliasing" problem

[attached png]
 the path on the left (30° grey lines) has been duplicated then transformed into a pattern => the aliasing become noticeable

I don't know if it matters but in the settings I choose a 16*16 oversampling bitmap.

[ScislaC (scislac)]

Confirmed with r12812, not reproduced with 0.48.4

[Tavmjong Bah (tavmjong-free)]

Patterns are turned into bitmaps which are then tiled. The only solution I see is to increase the resolution of the bitmap. The resolution is somewhat arbitrarily determined. I've increased the "scaling factor" from 1.1 to 2. (r12824 src/sp-pattern.cpp)

I also removed the oversampling preference (in r12823). It hasn't been used since the move to Cairo.

[su_v (suv-lp)]

Additional regression with r13111 (not reproduced with r13110):
The pattern in the sample file 'jitter.svg' fails to render visibly.

[su_v (suv-lp)]

@Tav - JFYI: the same change (pattern no longer renders visibly with rev >= 13111) was also observed with the original sample file of bug #953992 (“Imported pattern fill disappers while transforming”).

[su_v (suv-lp)]

Pattern renders visible again with the fix in r13120.

[su_v (suv-lp)]

Related follow-up report:
- Bug #1292459 “trunk: huge spikes of memory usage when zooming in closely on objects with bitmap pattern fill”
  <https://bugs.launchpad.net/inkscape/+bug/1292459>