VCA-1 produces visual glitches

[falkTX]

Not sure if issue with VCV or Cardinal.
But having this module on the board makes the entire plugin window green.
Moving VCA out of the way mitigates the issue.
Seems like the module is not closing/stopping a drawing operation properly, so the green used for its bars gets set for all modules.

[zezic]

For me it fills entire window with green only if its value is set below 0.005f, in another words, it does it when this condition is false: https://github.com/VCVRack/Fundamental/blob/v2/src/VCA.cpp#L242

But also, the following separators drawing procedure works in a strange way: https://github.com/VCVRack/Fundamental/blob/v2/src/VCA.cpp#L256-L262
The area it fills with black is too big:

And what's interesting, it renders correctly in the plugin browser, but not in the live mode.

[falkTX]

You are correct that this only happens if value is below 0.005f.
I think the code from VCA is wrong, there is a nvgFillColor + nvgFill being called where there is a potential for no nvgRect (when all gains are below that value)

Before digging deeper into this, we need to see if the same happens with VCV as well. The v2 branch.

[zezic]

At least the latest binary build of Rack v2 is not affected by this issue. I think it has something to do with the way NanoVG operates in the Cardinal (GL?) environment. Maybe debugging the wrong drawing of the separators will give some answers.

[falkTX]

good to know, thanks for checking.

I did some quick testing, and the area within the "meter" is simply not being drawn. if we extend the green area we can see the middle point where it should be drawn is the section where it is not.
Seems to me some logic is inverted somewhere.

[falkTX]

To make more clear what I mean, I extended the green rectangle 50px on each side.

But on the plugin browser it looks as intended.

[falkTX]

Oh, interestingly commenting out the separators makes the whole area bring drawn as expected.

[zezic]

Yes. It's omething wrong with them. I have some ideas to test. Gonna try to debug it.

[falkTX]

already found something, this code for the separators works:

		// Invisible separators
		const int segs = 25;
		for (int i = 1; i <= segs; i++) {
			nvgBeginPath(args.vg);
			nvgRect(args.vg,
			        r.pos.x - 1.0,
			        r.pos.y + r.size.y * i / segs,
			        r.size.x + 2.0,
			        1.0);
			nvgFillColor(args.vg, color::BLACK);
			nvgFill(args.vg);
		}

basically drawing each path separately.

so this is just joining each path together when drawing...?
there is an opengl config for this right?

[zezic]

You found it! :) I will try to search for anything related.
UPD: No luck for me anymore.

[falkTX]

I also had no luck despite trying many things.
Because this is a very popular module and the bug makes the cardinal plugin unusable, I added a workaround in b3fd44c

[falkTX]

Patch-fix has been submitted upstream in VCVRack/Fundamental#129

[falkTX]

Since I take it that upstream is pretty much never going to respond to that, I just setup a fork https://github.com/CardinalModules/Fundamental

No more workarounds needed, plus we need to start forking a few modules to send patches upstream. Otherwise my falkTX account will be flooded with forks.
And we want to link/reference the submodules to good repositories with fixes, not original ones that have yet to see PRs merged.
So https://github.com/CardinalModules is born 🎉