Add BASE table

[davelab6]

To improve rendering on the latest android with new support for BASE table, we should add a BASE table to Roboto Classic (especially Vietnamese)

[m4rc1e]

I've just used Font Height to calculate the max ascent and descent for the heaviest weight:

    5 tallest words:
      "Ǚ" => 2073
      "DỖ" => 1993
      "ĐỖNG" => 1993
      "Ǜ" => 1993
      "NGUYỄN" => 1993
    5 lowest words:
      "Enɡlish" => -426.45045045045043
      "Huɡh" => -426.45045045045043
      "Interroɡative" => -426.45045045045043
      "Ḁ" => -387
      "ḁk" => -374

The Android variable font has a winAscent of 2146 and winDescent of 555 so I don't understand what metrics values cause clipping in Android.

@belluzj do I still need to include a base table? Even though the win values (these cause clipping in win) are greater than what the tool discovered?

edit:

Just checked the yMax (2163) and yMin (-555). These are also within the bounds reported by fontheight.

[belluzj]

Hello, is Roboto actually clipping on Android?

[davelab6]

Yes, that's what Chris had discovered - Vietnamese clips in OOTB Android :(

But we don't know atm how often stacked diacritics are used in Android's system UI.

[m4rc1e]

So Android actually uses the hhea metrics, according to a doc I've just read. The Roboto Android release has a hhea ascent of 1900, so the reported glyphs will clip.