Problem with svg filters turbulence display in trunk

[ivan louette]

At 100% zoom load a bitmap, apply Filters/Image paint and draw/Point engraving filter

In 0.91 it displays correctly with the same appearance as when I create it (the filters are designed to work best at 100% zoom because of a display resolution dependance of some of their primitives, convolve matrix in particular )

In trunk some annoying regular pattern appears in the turbulence while displaying at 100% zoom.

If I zoom to 141% they disappear

Or if I remain at 100% zoom and change the turbulence frequency to 1.41 in XML editor they disappear too (see my attachment).

[jazzynico (jazzynico)]

Reproduced on Windows XP (32bits), Inkscape trunk rev. 14005.
Not reproduced with 0.91.

Note that the patterns show around the 100% zoom level (from 85% to 120%), and that the pattern size decreases when the zoom level increases.
Also note that the same patterns affect the image on the right (the one with frequency set to 1.41) when zooming from 120% to 170%.

[jazzynico (jazzynico)]

The issue doesn't seem to affect exported images, but canvas rendering only.