[Alephmodular-devel] Mumblings on buffers and drawing contexts

[Br'fin <br...@ma...>]

Mmmf, random nuisance. Trying to tie drawing commands to the drawing 
context and found myself painting myself into a corner, mildly.

Getting multiple drawing contexts for a buffer all works when you're 
accessing the exact same buffer. But there can be breakdowns if you try 
to access a drawing context for both a buffer and a clipped version of 
itself. Or worse, two different buffers which are each clipped versions 
of a third.

All of the screen_drawing.cpp stuff assumed a set_port call first. Now 
that stuff is enveloped in a drawing context. Works fine if everything 
is working with the normal working buffer. But woe unto the one who was 
trying to operate with a clipped version of the working_buffer and then 
calls those routines which then seek the drawing_context of the working 
buffer (as opposed to the clipped buffer....)

Anyhow, my choices are to either try and make it so that once a drawing 
context is declared, the current clipped buffer, the buffer that is its 
root and all other clipped buffers off that root just go right to the 
existing drawing_context. Or to just thread the current drawing_context 
down through the function stack as an argument. :)

I imagine that the latter is rightest, but don't know if I need to be 
worrying about efficiency... probably not, especially if I pass the 
drawing context as a reference anyhow.

-Jeremy Parsons