Re: Coordinate from device to user space without a context
Donn Ingle <[email protected]>
| Newsgroups | gmane.comp.lib.cairo |
|---|---|
| Message-ID | <CAHKKYP4UymLJE=pDA+Uqr-WMea4mcFJSFf1pg5AAog0X9KdYzg@mail.gmail.com> |
Perhaps someone can give a short cairo/gtk program (in c or vala) that demonstrates the use of that formula (and/or the invert thing) - that would embiggen grokkage. :D /d On 7 November 2013 16:24, Donn <[email protected]> wrote: > On 07/11/2013 15:48, ed44 wrote: >>> >>> So, x = [18,53,17,51] See the jumps? >> >> >> Yes , i see. >> But if you use the above formula and the matrix values are constant >> there should not be any jumps. > > > I'm not seeing the bug. > 1. The matrix does change because it has to. It comes from a translate(x,y) > [line 120], then gets saved into mymatrix [line 126], > 2. then the move() method causes x,y to shift to mousex,y [called from line > 39. The method at line 58] > 3. Then a queue_draw() happens [line 420] > 4. In draw(), a call to set_matrix(cr) happens [e.g. line 305], > 5. which is back to 1 were the latest x,y is used. > > Look, both you and Bryce tell me that formula should work as expected, so > I'm happy to think there's a bug in my code. I just gotta find it! > > Thanks for your time, > \d > (code attached this time.) > > -- cairo mailing list [email protected] http://lists.cairographics.org/mailman/listinfo/cairo