[cairo] Coordinate from device to user space without a context

Donn donn.ingle at gmail.com
Thu Nov 7 15:24:29 CET 2013

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,
(code attached this time.)

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