Re: [ft] Pitch Smaller Than Bitmap Width + Make Build Errors

[Werner LEMBERG]

>> Basically, it's a bug.  Theoretically, I could fix this by making
>> FT_Render_Glyph() call FT_Bitmap_Convert().  However, for backwards
>> compatibility, I fear this might not be a good idea, but I'm
>> unsure.
>
> 1) If one is writing a string rendering routine, previously they
> would have to support both 8bpp and 1bpp bitmaps.  If suddenly FT2
> stops giving 1bpp bitmaps, then all that means is that the code path
> for 1bpp is not used anymore.  The routine still works.  I bet many
> people like me already stumbled on this case, shrugged, and
> implemented the 1bpp code path, assuming this is correct behaviour.

Hehe.

I've now decided to leave the code as-is.  The main reason is that the
necessary bitmap conversion routines are in ftbitmap.c, which is an
add-on module not necessary otherwise.  Many people use FreeType only
for fonts without embedded bitmaps; calling FT_Bitmap_Convert()
automatically would just increase the code size without gaining any
effect.

Another reason is that the current behaviour actually *is* documented,
sort of:

  FT_Render_Mode
    ...

    An enumeration type that lists the render modes supported by
    FreeType 2.  Each mode corresponds to a specific type of scanline
    conversion performed on the outline.

    For bitmap fonts the ‘bitmap->pixel_mode’ field in the
    FT_GlyphSlotRec structure gives the format of the returned bitmap.

I'll try to improve the description.


    Werner