Re: Meeting minutes and the summary of WOFF2 changes

I'd prefer overlapSimpleBitmap.

On Tue, May 25, 2021 at 2:20 PM Vladimir Levantovsky <
vladimir.levantovsky@gmail.com> wrote:

> Minutes of today’s discussion are online at
> https://www.w3.org/2021/05/25-webfonts-minutes.html
>
>
>
> Summary of the WOFF2 changes to accommodate simple glyph flags bit 6
> (OVERLAP_SIMPLE) bit array (see Simple Glyph Flags description for details,
> https://docs.microsoft.com/en-us/typography/opentype/spec/glyf).
>
>
>
> In WOFF2 “Transformed ‘glyf’ table format” (
> https://www.w3.org/TR/WOFF2/#glyf_table_format), make the following
> changes:
>
> 1)      Change the datatype of the existing “version” field from Fixed to
> UInt16 with reserved value 0x0000.
>
> 2)      Immediately after the updated “version” field, introduce a new
> UInt16 field named “optionFlags”. Designate the bit 0x0001 to be the flag
> indicating the presence of the newly defined flag6Bitmap[] bit array.
>
> 3)      In the end of the table, add the UInt8 flag6Bitmap[] – a
> numGlyphs-long bit array that provides values for the flag [bit 6] for each
> simple glyph. (Flag values for composite glyphs are already encoded as part
> of the compositeStream[].)
>
> 4)      Add the following descriptive text:
> “The optionFlags field bit 0 indicates the presence of the additional
> flag6Bitmap[] bit array, all other bits are reserved and should be cleared.
> If all simple glyphs of the input font have OVERLAP_SIMPLE flags set to
> zero, the encoder MUST clear bit 0 of the optionFlags field and omit the
> flag6Bitmap[] bit array. If at least one of the simple glyphs in the input
> font have the flags bit 6 set, the encoder must set the optionFlags bit 0
> to “1”, and MUST create the additional flag6Bitmap[] bit array where the
> corresponding bits MUST be set to the values of the flag bit 6 of each
> simple glyph in the input font.
>
> The decoder MUST check the optionFlags bit0 value to determine whether the
> additional flag6Bitmap[] is included as part of the transformed ‘glyf’
> table. If the additional flag6Bitmap[] bit array is not present, upon
> reconstruction of the simple glyphs flags the decoder MUST set all
> OVERLAP_SIMPLE flag values to zero. If flag6Bitmap[] is included, the
> decode MUST use flag6Bitmap[] bit settings to reconstruct OVERLAP_SIMPLE
> flag values, and set the corresponding flag6Bitmap[] bit value as flag bit
> 6 on the first flag byte for each simple glyph of the output font”
>
>
>
> Question to the WG: I am considering two possible names for the new
> additional bit array – flag6Bitmap[] (used above as part of the proposed
> changes, which is derived from the simple glyphs flags bit 6 value), or the
> more verbose [and more descriptive] “overlapSimpleBitmap[]”.
>
> What would be your preference for the new array name?
>
>
> Thank you,
>
> Vlad
>
>
>
>