From: Patrick Lam (plam@plam.lcs.mit.edu)
Date: Sun Jun 29 2003 - 17:01:30 EDT
On Sat, Jun 28, 2003 at 11:30:39AM +0100, Tomas Frydrych wrote:
>
> We currently draw the selection rectangles using fillRect() function,
> and this is not optimal. It would be better if we had a xorRect()
> function and use it instead. The main benefit would be that the text
> of the whole run could be drawn in a single go in a single colour.
> While the performance gain is probably negligeable, it would mean no
> need to decompose ligatures on selection boundaries. (The screen
> redraw always starts with filling the base rectangle with background
> colour, so this would not mean the dirt problems we experienced with
> the carret.)
The problem with xor drawing is that it's practically impossible to
keep a consistent state and avoid screen dirt; for instance, we happen
to not get told when the OS decides to redraw something behind our back
(not XORred). This was particularly bad with the caret but I'd expect
that selection would have this problem too.
pat
This archive was generated by hypermail 2.1.4 : Sun Jun 29 2003 - 17:13:09 EDT