[MACTCL] Woeful canvas performance 8.5.2

[Jasper T. <ja...@si...>]

I recently installed the ActiveTcl 8.5.2 distribution on my C2D  
Macbook in the hope that it would fix some problems in graphical  
performance that I have been having with 8.4.17. To my dismay, it was  
far, far worse! Here is a little code snippet to make 10000 items on a  
canvas...

pack [canvas .c -width 1000 -height 1000 -bg \#ffaaff]
for {set y 0} {$y < 1000} {incr y 10} {
     for {set x 0} {$x < 1000} {incr x 10} {
         .c create line $x $y [expr $x+5] [expr $y+5]
     }
}

Run this, and you will find that resizing the wish window takes about  
1 second when the whole canvas is displayed, and proportionally less  
when less of the canvas is showing. On 8.4.x you get comparable  
performance when you reduce the increments to 3, thus displaying more  
than 10 times as many items. And under Windows and Linux there is no  
noticeable delay at all even at this setting.

Does anyone have any idea why this should be? And is it being fixed?  
Could I help? I've written lots of TclTk and c++ code but done no Mac  
Carbon or Cocoa development.

	--Jasper