Fontweight Bolder == Bold when Bounds are computed?

[foxmichaels]

Description

Not sure if this is a known issue or not. Using the latest (as of now, 3.1.1), Bounds seems to treat "Bolder" (W900) the same as "Bold" (W700). This is despite them showing correctly (Bolder is thicker than Bold) in browsers and Illustrator and online SVG viewers.

Example data

SvgText txt1 = new SvgText
{
	FontFamily = "Helvetica",
	FontSize = new SvgUnit(SvgUnitType.Pixel, 12f),
	FontWeight = SvgFontWeight.W900
};
SvgTextSpan txts1 = new SvgTextSpan { Text = "TEST-FONT" };
txt1.Children.Add(txts1);
txt1.Bounds.Height = <value>

In the above code, <value> will be the same if FontWeight is set to W900 and W700. It will adjust properly when FontWeight is set to W400.

Have tested this on a handful of fonts (to rule out a font issue) - including: HelveticaNeue, Helvetica, Times New Roman, Courier New, Arial.

Used Versions

SVG 3.1.1, .NET 4.8

I didn't see this listed as an issue, so thought I would mention it.

Thanks!

[H1Gdev]

font-weight is displayed using System.Drawing.FontStyle(Regular or Bold).

It is assigned as follows.

font-weight	System.Drawing.FontStyle
100 - 500	Regular
600 - 900	Bold

So, 900 same as 700.

[foxmichaels]

Interesting, thank you. Looking into it, I see that yeah, they're the same in System.Drawing.FontStyle.

Would it be possible to implement something using the Font.FromHfont, like:

IntPtr hFont = CreateFont(-13, 0, 0, 0, 100, 0, 0, 0, 1, 0, 0, 0, 0, "Arial\0");
Font.FromHfont(hFont)

I haven't yet clones the repository so I need to see first how the fonts are being generated. If it's possible, I may clone and try giving it a shot. :)

Thanks!

[foxmichaels]

Update - I tried it, just to rule it out as a possibility. This code:

[DllImport("gdi32.dll")]
static extern IntPtr CreateFont(int nHeight, int nWidth, int nEscapement,
   int nOrientation, int fnWeight, uint fdwItalic, uint fdwUnderline, uint
   fdwStrikeOut, uint fdwCharSet, uint fdwOutputPrecision, uint
   fdwClipPrecision, uint fdwQuality, uint fdwPitchAndFamily, string lpszFace);

[...]

// Get the font-family
var font2 = CreateFont(66, 0, 0, 0, 700, 0, 0, 0, 1, 0, 0, 0, 0, "HelveticaNeue\0");
return new GdiFontDefn(System.Drawing.Font.FromHfont(font2));
//return new GdiFontDefn(new System.Drawing.Font(ff, fontSize, fontStyle, System.Drawing.GraphicsUnit.Pixel));

Was put into place in SvgElementStyle.cs, lines 462-465 in 3.1.1 master.

This was just to test the FontWeight. Ran the code three times - sending 400, 700, and 900 as values for fnWeight. interestingly the putput was still the same for 700 and 900 - so this is not an answer, sadly.

I am curious now how AI and the browsers make the font thicker, but it looks like this is a dead end.