[Gnash-dev] Questions about frontends

[Udo Giacomozzi]

Hello,

we got now some time again to investigate Gnash for our DirectFB port.

We did some sort reverse engineering by tracing the function calls for
a minimalist SWF 5 file that just contains a few straight lines.

It seems that a simple line is divided into various segments (line
strips). Probably that design comes from the OpenGL world?

However, it seems that this is done by the "tesselator" that is used
to give a line it's shape.

What I don't understand is why the points along the line are like
logarithmically spaced and there is no relationship to the shape of
the line. Say, we have a line with width 200 and the points are all
along the center of the line. Why?

Can this avoided altogether, say, have the line properties passed to
the frontend and let it draw the line the way it likes?

Also, hairlines seem to be converted to shaped lines - correct?

Maybe that's part of the frontend API redesign and I would strongly
suggest it...

Anyway, we really need some clarification of the internal structure of
the drawing part.

Attachments: Test SWF file and the points passed to line_strip()

Udo

coords.jpg
Description: image/pjpeg

line-thickness.swf
Description: application/shockwave-flash