FormCanvas>>transformBy:clippingTo:during:smoothing


Hi Hal,

This is terrific.

I've been look into things that make squeak slow and
been somewhat stumped on ways to repair it. This sound
like a major clue.

The best place for this info would be to start a
Mantis report. (You can get a mantis acct freely and
easily). 

A good place to start is:

http://bugs.impara.de/my_view_page.php

Mantis provides a patient persistent way to focus on
an issue.
I use it to accumulate data on a problem until a
solution can be found.
It provides a place to alert the community to a
problem; 
-accumulate facts and clues from the analysis;
-publish preposed solutions and get feedback;
-get solutions havested and included into the main
stream.





> 	
>FormCanvas>>transformBy:clippingTo:during:smoothing
>Hal Eden haleden at colorado.edu 
>Mon Sep 18 21:19:33 UTC 2006 wrote:

>hi,
>
>i've been puzzling over the slow performance of
Transform*Morphs when  
>their size becomes larger. (haven't found found much
on the web  
>beyond some vague references to slowness and some
defunct threads on  
>related subjects).
>
>doing some profiling, i found that the issue is that
if the  
>transformation is more than just a translation, a new
subcanvas is  
>allocated, the area to be transformed is drawn to
that subcanvas,  
>then the result is warped to the original canvas.
>
>all well and good--for small transformation areas,
but it turns out  
>that allocating the form often takes more time than
is desirable if  
>the form is much larger than 600x600 (x32bits). on my
mac i found it  
>taking 4-6 seconds. definitely enough to put a dent
in smooth  
>interaction.
>
>i've been noodling around with a different approach,
one which stores  
>the transform in the GrafPort, so that when the
actual drawing takes  
>place, the transform is used.
>
>my results are that for a 600x800 image form, the old
way timeToRun  
>is about 4700, with the experimental way, it is round
50.
>
>i only played enough to get images working so far and
can see that it  
>would not be trivial to make it work for everything.
>
>my question is, how would i go about pursuing this
further in a way  
>that might be useful "out there"--is anyone working
on morphic  
>maintenance?

Well yes, I remain interested in improving morphic.
There are others.
There is more to be said on this but thats for another
time.
>
>or is the real culprit my VM's memory allocation?
>
>thanks,
>
>hal


__________________________________________________
Do You Yahoo!?
Tired of spam?  Yahoo! Mail has the best spam protection around 
http://mail.yahoo.com