Crash when trying to read the horizontal header of a TrueType font

[wldevries]

Crash in Face when trying to read the horizontal header of a TrueType font.

var library = new Library();
Face face = new Face(library, "c:/windows/fonts/arial.ttf");
face.GetSfntTable(SfntTag.HorizontalHeader);

This results in the following error:

System.TypeLoadException: Cannot marshal field 'Reserved' of type 'SharpFont.TrueType.lnternal.HoriHeaderRec': This type can only be marshaled in restricted ways.
at System.Runtime.lnteropServices.Marshal.PtrToStructureHelper(lntPtr ptr, Object structure, Boolean allowValueClasses)
at System.Runtime.lnteropServices.Marshal.PtrToStructure(lntPtr ptr, Type structureType)
at SharpFont.PlnvokeHelper.PtrToStructure[T](lntPtr reference)
at SharpFont.TrueType.HoriHeader.set_Reference(lntPtr value)
at SharpFont.TrueType.HoriHeader..ctor(lntPtr reference)
at SharpFont.Face.GetSfntTable(SfntTag tag)

I'm trying to get to get access to the LineGap of a font which seems to be present only in the vertical and horizontal headers. The vertical header loads fine.

[HinTak]

loadfont() does not appear to be a known routine?

[wldevries]

I updated the repro code to include how the font is loaded.

After fiddling around with it today I found that this is only a problem in the SharpFont build included in the MonoGame pipeline. It works fine when I use the nuget package SpaceWizards.SharpFont. (the more official SharpFont package does not work on modern .NET versions: #126)