[pygtk] pycairo - translate question

[Gustavo J. A. M. Carneiro]

On Seg, 2007-11-05 at 17:38 +0200, Donn wrote:
> Hi, not sure if this is the appropriate list.
> 
> Can one, within a single cairo context, do this:
> 
> while True:
>   ctx.translate(0,0) 
>   <pycairo commands to draw a square at 0,0>
>   ctx.translate(10,10)
>   <pycairo commands to draw a circle at 0,0>
>   ctx.translate(50,50)
>   <pycairo commands to draw a Black Night at 11,44>
> 
> The idea is to keep all the <drawing commands> relative to 0,0 and use 
> translate (and scale etc later) to actually move the results around the 
> canvas. I picture it a bit like a stamp that moves to (x,y) and then draws 
> the vectors in <> down at that point, then moves on.
> 
> My actual code is building a stack of pointers to draw() functions (in other 
> objects) that gets run in a tight loop: pop, draw, pop, draw, etc.
> 
> At the moment my tests are all over the place. Is there a way to reset the 
> overall transform between each <> section?

Yes.  Do stuff like this:
  ctx.save()
  ctx.translate(10,10)
  <draw stuff>  
  ctx.restore()

-- 
Gustavo J. A. M. Carneiro
INESC Porto, Telecommunications and Multimedia Unit
"The universe is always one step beyond logic." -- Frank Herbert