Re: gEDA-user: pcb program

[Harry Eaton <haceaton@xxxxxxxxx>]

I noticed the problem is occuring during an extremely
high zoom in. pcb used to have code to clip the zoomed
lines to the screen in order to prevent integer
overflow. With the advent of hid that was removed and
now zooming in runs the risk of overflow with its
unlimited zoom capability.

It's very severe with rats because all rats seem to be
being drawn, even those that should not be visible at
all - thus virtually all of them are overflowing.

First recommendation is don't zoom in so close with
rats on.

Second thing is we should fix the drawing so that it
only draws the visible rats. I thought it already did
that.

Third is it's time to put proper clipping into the hid
drawing routines.

Interesting polygons are the only structures being
properly clipped at the moment.

The polygon clipping is "slow" when the polygons have
many thousands of verticies. I'll be improving this
situation this spring by (a) reducing a circle's
vertice count to 20 from 36 (this is still more than
many commercial packages). (b) cacheing the "diced"
polygons used for rendering and (c) Modifying the file
format to store the clipped polygon data so that file
loading is fast if the clip information is saved.

h.



 
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