Why does 'Scribble' makes GH canvas so slow?

I haven’t found many posts referencing this issue, I thought it was well known by now, but just in case…

Big scribble texts make the GH canvas super slow. Deleting the scribble item returns everything to smooth panning.

@DavidRutten David are you aware of this?

I am using the the ‘scribble’ command to type text.

:sleeping: I shouldn’t answer when sleepy

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Scribbles have to be converted from text to shapes when drawn, so drawing them is very graphically intense. All the speedups that come with fast text rendering go out the window. ^1

The text also needs to be converted into shapes for the purposes of mouse-hit testing.

^1 Actually there’s a possible optimisation here, maybe I can get away with just setting up a display transform instead. But drawing large blocks of text isn’t exactly fast either in GDI+…

I see. Basically what has almost always lead me to using Scribble instead of a Panel with transparent background color, is the fading… If there was a way to override the panel text fading or editing its proportion regarding the zoom value I would not need to use Scribble

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I thought the text shape is cached

So THAT is the reason! I have my definitions literally littered with scribble titles in the groups… Sigh.

Without the titles (scribble captions) the GH definitions are unreadable and by being so slow it’s almost unusable. Difficult choices to be made.

// Rolf

It is, but just drawing hundreds of individual GraphicsPath shapes is much slower than drawing a string, be they cached or not.

Initial tests show that there’s almost no benefit to be had by switching to straight up text rendering with a transform. If anything it feels slower.