Hi,
Having looked at the librsvg code recently I thought I'll see if I could
re-write it in python, with freetype-py / pycairo and gobject introspection of
librsvg. Here it is.
https://github.com/rougier/freetype-py/pull/174
There is currently a small flaw I hope to fix in another commit soon: it is a
bit painful to allocate a python object/dictionary to keep the state of the
rendererhook, and pass it back and forth to c-side of libfreetype, so it is
currently a client side global.
On the way I found two little flaws with the original c code - cairo's RGBA32
format is host native, while freetype's RGBA bitmap is small-endian. It works
at the moment, because the generation of color bitmap and drawing with the
bitmap are both via cairo; this strictly-speaking means on some platforms the
color bitmap stored in freetype isn't what it says on the tin...
The other little thing is that there is a small redundancy - the svg layer
rendering code in librsvg can take null to draw the whole svg document - so
there is no need to use both document-render and layer-render. That would cut
out a large if/then block with some 20 lines.
A third thing: the layer drawing code also doesn't check glyph id is between
start and end - should it? It probably would have flagged the recent Google
font bug there, where the glyph id is outside start/end, from bug in subsetting.
This, plus dropping older librsvg support (gobject actually emit deprecation
warnings per run!), and python variables don't need to pre-declare / cast to
and from double to int, means the equivalent python code is less than 1/2 the
length of rsvg-port.c .
I'll hope to fix the state global issue soon. That rendererhook API with a
pointer to pointer argument is a bit painful to use with non-C language - can
we do something like the Contour_Compose() callbacks next time, with a single
pointer which is carried around?
Oh, this use gobject introspection so is probably not too portable (ie
windows), and depends on a few gtk/gnome-ish things. Wonder if it works on
windows with windows libgobject?
