Re: Opening large DXF file
Posted by
dazky on
Jan 05, 2015; 10:58pm
URL: https://forum.librecad.org/Opening-large-DXF-file-tp5710920p5710921.html
Hello,
I tried in AutoCAD
2014, Windows 8.1,
Intel I5-4460S
- 2.90
GHz,
8 GB RAM
1) open a
file - 5s
2) zoom
/ pan - as small files,
without delay
3) selection
of all entities by window - 4s
4) move all entities - 5s
5) copy
of all entities - 6s
at
max. zoom
circles are shown as a hexagon
D.
Dne 5. 1. 2015 v 23:12 R. van Twisk
[via LibreCAD] napsal(a):
See,
http://forum.librecad.org/open-big-DXF-file-td5709234.html
Out of curiosity with somebody with auto cad. How fast does the
full drawing pan on screen. That is when all circles are visible?
background: We are working on a new version of LibreCAD and have
been looking in area's where we can optimise performance. One of
the way to do this is using a QuadTree (http://en.wikipedia.org/wiki/Quadtree)
However, no matter how you look at it, when all entities are drawn
on screen you will have to iterate over all entities to draw them.
Arguably you can leave small entities out and you can do this by
asking the QuadTree implementation to only return all entities
up-untill some depth level. LibreCAD 3 can do this using a level
indicator (see http://wiki.librecad.org/lc3doc/lckernel/html/classlc_1_1_quad_tree_sub.html#a5e98edfcecde70c3ec4fbea6148ce52a)
However, the drawing is constructed such that we have many many
small circles into each other not having a 'small' enough circle
to not draw it.
Also when you 'zoom in' you can ask the QuadTree to only return
the entities that are possibly visible on screen. The retrieve
function supports a 'area' that will only return all entities
within a specific area note: QuadTree does this roughly, we
have more refined functions for exact matching in
EntityContainer
I can compare ourselves with DraftSight, and the large file is
also very very slow on DS. However, I cannot compare with AutoCAD
because I don't have such license.
Just curious...