Opening large DXF file

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...


Update 1: I was just be able to test Teigha viewer and although zoom in/zoom out was faster then DraftSight (but not fluid) I noticed that when zoomed in I just see that AutoCAD renders circles are 6 lines.
Apparently this is a feature from AutoCAD and you need to hit region to show the drawing correctly again.

I know that may be some of you might want to yell use pure OpenGL! But that can open a other set of problems something that's not easy to solve.

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.

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...

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NAML

hello dazky,

thanks for testing that for us! This gives us a idea what to expect and what to lookout for.

As mentioned, it's very hard to optimise this sort of file and really doesn't represent anything you would create in the real world as a CAD type of file..

obviously, we are always interested in more performance!