Re: Set_Pixel_Sizes for TTF

[Yamano-uchi, Hidetoshi]

Hello,

From: Werner LEMBERG <address@hidden>
Subject: Re: Set_Pixel_Sizes for TTF
Date: Sun, 15 Oct 2000 22:07:10 +0200 (CEST)
Message-ID: <address@hidden>

> Question: How can sbit ppem values different from outline ppem values
> be handled automatically within an application?

The weight of sbit glyphs is often LIGHTER from the weight of outline.
In fact, many Japanese computer venders (e.g. NEC, Canon, etc.) use
OLD bitmap fonts (for Japanese DOS or old word-processors, etc.) as
embedded bitmaps for NEW outline fontfiles.

In this case, it is useful to synthesize "double striked" glyph from
"small ppem" bitmaps.

> What about this:
> 
>   Plan 4a:
>     We provide APIs A and B and add an sbit_metrics field to a
>     TrueType-specific structure.

Plan 4b:
     We change FT_SizeRec as following way.

typedef struct  FT_SizeRec_
  {
    FT_Face          face;      /* parent face object              */
    FT_Generic       generic;   /* generic pointer for client uses */
    FT_Size_Metrics  metrics;   /* size metrics                    */

    FT_Generic       driver_private; /* generic pointer for font drivers */
  } FT_SizeRec;

sbit_metrics = (FT_Size_Metrics*)size->driver_private;

And driver_private is NULL when we use a TTF font without sbits or
without outlines.

Any comments or objections?

----- Yamano-uchi, Hidetoshi