help with speedy graphics

[Alex Tweedly]

At 11:31 14/07/2004 +0930, Monte Goulding wrote:

>Just out of interest have you tried using a single polygon graphic with
>markers and no line and just setting the points. That should be very fast.

Nope - had no idea until 5 minutes ago that that might be possible. Thanks 
to Richard and Dar, I am trying it now ....

btw My earlier reply to Dar was wrong; it's NOT necessary to duplicate each 
point to get a visible (though zero-length) line drawn - it's enough to 
simply put each vertex where a shape is wanted, with blank lines (in the 
point list) in between.

Doing this (and always keeping a base polygon in existence, so it can be 
modified and never drawn from scratch) makes it much more palatable - 70x70 
draw time is down from 700 to about 95 ticks. Still a perceptible delay - 
but one that I'd feel comfortable saying "just live with it".

(I'm porting this app from a different scripting language,. where the draw 
times are sub-second up to 5000 data points - so there's a limit to what I 
can expect people to adjust to).

Someone pointed out earlier that these polygon schemes limit me to a single 
colour. That is indeed the very opposite of what I need - the visualization 
I want is done by colours. However, I'll have typically a small number 
(~4), and rarely more than 10-15 different colours. So it won't be as fast 
as a single polygon - but it should be within the acceptable range.

I'll do a proper write-up of the schemes and times tomorrow (it's almost 
4am here :-) for the sake of the archives.

Thanks again for all the help.
-- Alex.
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