Pen Thickness is not taking into account when calculating bounding boxes/clip rectangles.

[nitroxis]

When drawing e.g. an ellipse into an image with just the outline, it will always get cut off at the edges because the bounding box appears to only consider the "fill" area, not the whole outline.

A simple repro:

<Image Width="500" Height="500" Stretch="None">
	<Image.Source>
		<DrawingImage>
			<GeometryDrawing>
				<GeometryDrawing.Pen>
					<Pen Brush="#000000" Thickness="10"></Pen>
				</GeometryDrawing.Pen>
				<EllipseGeometry RadiusX="100" RadiusY="100"></EllipseGeometry>
			</GeometryDrawing>
		</DrawingImage>
	</Image.Source>
</Image>

This currently looks like this:

If this is intentional behavior, what is the proper way to make this look like a normal circle?

[kekekeks]

Probably a bug somewhere here

Avalonia/src/Skia/Avalonia.Skia/GeometryImpl.cs

Line 89 in c85fa2b

public Rect GetRenderBounds(IPen pen)

[Gillibald]

cf15520

[nitroxis]

I checked the method you mentioned but the bounds look correct there:

This is for the above example geometry, which is correctly calculated at 200x200 for the fill + 10 for the stroke. The bug might be somewhere else?

[nitroxis]

Okay I've investigated this a bit more. Seems like the first calls to GetRenderBounds from here

Avalonia/src/Avalonia.Visuals/Media/GeometryDrawing.cs

Line 71 in de0774a

return Geometry?.GetRenderBounds(s_boundsPen) ?? Rect.Empty;

supply a pen with Thickness 0. Later, when the method is called from here:

Avalonia/src/Avalonia.Visuals/Rendering/SceneGraph/GeometryNode.cs

Line 27 in 6adb3ea

: base(geometry.GetRenderBounds(pen), transform)

the pen is correct. I think the Pen property is not fully initialized when layouting or UpdateScene is called for the first time or something?

[nitroxis]

Ah no, s_boundsPen is simply an immutable Pen with Thickness always 0. I guess this is the problem then, it should probably use the real pen?

[kekekeks]

@grokys

[Gillibald]

GetRenderBounds should not require a Pen to work properly. Instead, the API should be changed to take a thickness.

[joneuhauser]

I also mentioned this bug here: #4913

[Tenjim]

I notice that bug is also related to : #8080

[Whiletru3]

Hello, this bug is annoying as all the icons are cropped in the interface, is there any plan to fix this ?

Thanks

[Whiletru3]

In GeometryDrawing.cs, the GetBounds should be changed from this

public override Rect GetBounds()
        {
            return Geometry?.GetRenderBounds(s_boundsPen) ?? Rect.Empty;
        }

to this (to take the Pen of GeometryDrawing if exist

public override Rect GetBounds()
        {
            IPen pen = Pen ?? s_boundsPen;
            return Geometry?.GetRenderBounds(pen) ?? Rect.Empty;
        }