[Freetype] rendering a string, using outlines, in mono

[Vincent Torri]

hello,

i want to render a string, on 1-bit bitmap, using the outlines of the
glyph (FT_Outline_Get_Bitmap). I have 2 questions:

1) when i render the string in a big bitmap (say, the BBox, which i have
computed before rendering), only the last character is rendered. It seems
that at each call of FT_Outline_Get_Bitmap, this one clear the bitmap that
i give to it. Is it the case ? Does it only create "standalone" bitmap
? (from the doc: "Renders an outline within a bitmap. The outline's image
is simply OR-ed to the target bitmap")

2) the second question is related to the translation of a outline. I
wanted to translate the characters of the strind, with
FT_Outline_Translate, but, it seems that if i give the vector in pixel
unit, it's not sufficient. I have to multiply the value of the offset that
i give (that is, the pen position, expressed) by something like 4. I don't
understand why this factor arises (why 4, and not 1<<6, as the coords of
an outline is expressed in 26.6 format)

thank you

Vincent TORRI