Re: When Should You Call cairo_surface_flush?
Lawrence D'Oliveiro <[email protected]>
| Newsgroups | gmane.comp.lib.cairo |
|---|---|
| Organization | Geek Central |
| Message-ID | <[email protected]> |
On Wed, 18 Mar 2015 22:27:32 +0100, Uli Schlachter wrote: > In the current implementation it is safe to *read* from an image > surface's data without calling flush. Writing does need a flush > before, so that snapshots get detached and surface snapshots can make > a copy of the old contents. > > However, this is an implementation detail and not guaranteed by the > API. Thank you for that. Perhaps this should be made clear in the docs <http://cairographics.org/manual/cairo-cairo-surface-t.html#cairo-surface-flush>: the sentence This function must be called before switching from drawing on the surface with cairo to drawing on it directly with native APIs. should become more like This function must be called before switching from drawing on the surface with Cairo to making any kind of accesses to its memory outside Cairo. Can we also take it as read that, if the implementation changes in future, the cairo_write_to_pngxxx calls will be updated to do any necessary flushing? Which means the flush() calls in my sample code can go? -- cairo mailing list [email protected] http://lists.cairographics.org/mailman/listinfo/cairo