Hi,
Seen the bugreport.
And as I said in the other reference:
It is quite hard to put your finger on when and what.
Still buzzing ... got a tool to create patterns from entities in the pipeline.
I speak from experience, made many hundred hatches, large ones, complex patterns and with huge offsets or spans.
At a certain point you stop with putting more in one and the same dxf because of the lagging.
Or run dozens of tests with one single squared-out boundary and one hatch pattern and hope it doesn't time out.
The case you present is one of the category 'Focusing'.
Moving the cursor over a drawing or zooming with the mouse-wheel are both mouse actions.
Using + / - on the keyboard is that not.
Try both together what is hard to evaluate.
Try pointing inside and lift your mouse when zooming with the mouse-wheel.
Qcad constantly updates the focus to the nearest entity on mouse actions.
Solid hatches get the focus when you sit inside the boundary and no other entity is in the vicinity.
Patterned hatches get the focus when you are near one of the hatch segments.
In doing so, one can select entities covered by a hatch as long as you know exact where to point at.
Patterned have also a reference point where an individual line segment touches an entity at the boundary.
I can't come up with a pratical use for them.
That are a vast amount of evaluations to be made just to figure out if any counts as focus.
Viewports add another layer of: am I ... or am I not focused? But then focusing as one whole.
And it seems that even when locking the layer(s) with the hatches, hatch segments are evaluated in viewports.
Focusing or not is changing the displayed color.
That of the viewport, with all its hatches, with all their line segments ...
The lagging is the computational effort to evaluate all this and set or clear the focus.
The math is extremely fast, the problem is the quantity.
A solution in your case could be locking layer 'A--L$3A__V-ports'.
Then mouse zooming acts the same as if you where pointing in the void.
But you figured that out yourself. (Bugreport)
This is not the end of the story:
-Size - Position - Complexity
-Selected - Selection changes
-Moving - Pasting and their preview
But also layer manipulations and their properties.
Even hiding or frezing a layer with a laggy hatch!?
cccplex wrote: ↑Sun Jun 14, 2020 5:01 pm
Or is having a central reference point that much easier for the renderer?
Yes, about always ... It's less effort and still pretty accurate.
https://qcad.org/rsforum/viewtopic.php?f=30&t=6887
Halfway the first page ... (Read all if you like).
In the file dXshift Fix.dxf one can see how segment 101 is rendered in:
- the neigbouring 'Tile' ->35th clone & 34th repetition
- an equal tile at position (10000,10000) ->710000th clone & 690286th repetition
Central,
No, if you don't want the hatches with the same pattern to shift regarding the others.
Keep it near, that is the message.
Regards,
CVH