Suggestion for making QCAD "feel" faster
Moderator: andrew
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Suggestion for making QCAD "feel" faster
Please note that I'm not trying to start a software war in this thread. I have noticed that the latest version of LibreCAD feels snappier or more responsive than the latest version of QCAD. This is when I'm working with large or complex drawings. Looking more closely at how they did this, every time I press the middle mouse button to pan the viewport, the texts become rectangles. When I release the mouse, the text appears again. My suggestion is that maybe the QCAD team can look at how LibreCAD did it, since it is open source and based on Qt (and the fact that LibreCAD is a fork of QCAD), and implement the same technique. I really hope that this can help make QCAD feel faster as well.
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Re: Suggestion for making QCAD "feel" faster
Hi,
Knowing that LibreCAD was forked from QCAD Community Edition 2.0.5
I don't think that the architecture is greatly improved in regards of speed.
However, performance enhancements are an ongoing process in QCAD, sometimes at the cost of ...
At a certain point, drawings are just too complex to be well handled by QCAD.
It is more the entity count that matters, among other issues there is what is called 'Massive blocks' (Recent example)
Question: What is your preference for rendering Text entities? As paths or as text?
If there are that many Text entities to render, then perhaps it is an idea to Hide/Lock/Freeze them on a dedicated layer for the time being.
In the mean time do the same for Hatches.
To be honest: I don't pan with the middle mouse button often.
It feels unnatural to: And apply pressure, and move the mouse freely.
If I want to pan, I activate panning with ZP.
We already see placeholders when the text becomes tiny in a certain zoom state.
Your proposition is certainly valuable in the case of panning with the middle mouse button but also limited for that case.
Depending the button state there is a clear start and end for the panning mode.
For zooming or panning differently there could be an elapsed time trigger to render text back as normal.
Regards,
CVH
Knowing that LibreCAD was forked from QCAD Community Edition 2.0.5
I don't think that the architecture is greatly improved in regards of speed.
However, performance enhancements are an ongoing process in QCAD, sometimes at the cost of ...
At a certain point, drawings are just too complex to be well handled by QCAD.
It is more the entity count that matters, among other issues there is what is called 'Massive blocks' (Recent example)
Question: What is your preference for rendering Text entities? As paths or as text?
If there are that many Text entities to render, then perhaps it is an idea to Hide/Lock/Freeze them on a dedicated layer for the time being.
In the mean time do the same for Hatches.
To be honest: I don't pan with the middle mouse button often.
It feels unnatural to: And apply pressure, and move the mouse freely.
If I want to pan, I activate panning with ZP.
We already see placeholders when the text becomes tiny in a certain zoom state.
Your proposition is certainly valuable in the case of panning with the middle mouse button but also limited for that case.
Depending the button state there is a clear start and end for the panning mode.
For zooming or panning differently there could be an elapsed time trigger to render text back as normal.
Regards,
CVH
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Re: Suggestion for making QCAD "feel" faster
Hi CVH,
Thank you for the support and concern.
It's very hard for me to explain in text.
Perhaps a video would be a better fit for this case.
Please give me about an hour or two to record one and upload it to YouTube.
Thank you for the support and concern.
It's very hard for me to explain in text.
Perhaps a video would be a better fit for this case.
Please give me about an hour or two to record one and upload it to YouTube.
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Re: Suggestion for making QCAD "feel" faster
Hi again CVH,
Here is the video as promised.
https://youtu.be/gXHSrul8PaM
Sorry it took longer than expected. I had to take a break as it was after midnight.
Here is the video as promised.
https://youtu.be/gXHSrul8PaM
Sorry it took longer than expected. I had to take a break as it was after midnight.
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Re: Suggestion for making QCAD "feel" faster
Hi,
I suspect that text entities alone are not the whole story.
Would it be possible to attach the used file?
So that we can experiment with it at our side.
If considered as too proprietary for a public forum then you may send it by Private Message.
(The easiest way is to click on my username and take it from there)
The bug that you report for text disappearing is sometimes seen while rendering text as text.
Also, you didn't answer on the question:
CVH
I suspect that text entities alone are not the whole story.

Would it be possible to attach the used file?
So that we can experiment with it at our side.
If considered as too proprietary for a public forum then you may send it by Private Message.
(The easiest way is to click on my username and take it from there)
The bug that you report for text disappearing is sometimes seen while rendering text as text.
Also, you didn't answer on the question:
Regards,
CVH
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Re: Suggestion for making QCAD "feel" faster
Hi again CVH,
Unfortunately the file is classified as the copyright belongs to my client.
But anyway, I tried to change the text rendering setting to path, and you are right, now QCAD seems to be as fast as LibreCAD!
So refreshing!
I just changed the status of my YouTube video to "unlisted" so it will not be discoverable by people.
Please, are there any other settings that can make QCAD "feel" faster?
Unfortunately the file is classified as the copyright belongs to my client.
But anyway, I tried to change the text rendering setting to path, and you are right, now QCAD seems to be as fast as LibreCAD!
So refreshing!
I just changed the status of my YouTube video to "unlisted" so it will not be discoverable by people.
Please, are there any other settings that can make QCAD "feel" faster?
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- Premier Member
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Re: Suggestion for making QCAD "feel" faster
Most certainly yes.
But I really need a file example for that.
In general:
- Define Hatch entities on a dedicated layer and lock that for the time being.
- Do the same for bitmaps.
Hiding these if not really required.
- Avoid too dense Hatches, avoid somewhat complex patterns, avoid bad coded patterns.
- Avoid 'massive blocks' like everything in a Block or a Block for all of a first floor, another for all of a second floor ...
- Avoid stacked Blocks or Block in Block constructions in too numerous levels.
- Avoid splines above degree 3.
- Avoid files like the recent example given, chop that up in partial drawings.
Effectively reducing the entity count.
# EDIT #
- Many large bitmaps is mentioned to slow down QCAD.
- Increase the Auto-save interval or disable that.
Regards,
CVH
But I really need a file example for that.
In general:
- Define Hatch entities on a dedicated layer and lock that for the time being.
- Do the same for bitmaps.
Hiding these if not really required.
- Avoid too dense Hatches, avoid somewhat complex patterns, avoid bad coded patterns.
- Avoid 'massive blocks' like everything in a Block or a Block for all of a first floor, another for all of a second floor ...
- Avoid stacked Blocks or Block in Block constructions in too numerous levels.
- Avoid splines above degree 3.
- Avoid files like the recent example given, chop that up in partial drawings.
Effectively reducing the entity count.
# EDIT #
- Many large bitmaps is mentioned to slow down QCAD.
- Increase the Auto-save interval or disable that.
Regards,
CVH
Last edited by CVH on Tue Sep 09, 2025 8:49 am, edited 2 times in total.
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Re: Suggestion for making QCAD "feel" faster
Thank you CVH!