salshaaban/bidirenderer

An example / demo application that illustrates the shaping and layout of complex text in bidirectional paragraphs using FriBidi, FreeType, and HarfBuzz

BidiRenderer:

This is a test application I'm using to help me understand the Unicode bidirectional algorithm, and the process of rendering complex scripts and RTL text. It's the basis for a more complex version of the code that has been used in VLC's FreeType module for subtitles/OSD rendering.

Some options do not produce visible effects on all fonts. For example removing zero-width characters when the font can already handle them properly. The font Arial is good here since it shows zero-width spaces, Unicode control characters, etc.

See the wiki for build instructions on Windows and Linux/Unix.

I welcome any comments or corrections, particularly regarding language-specific issues.

bidirenderer's Issues

Build instructions

Can you please include a makefile or other build instructions? Thanks.

Line width issue

The assert in GlyphString::newLine() is failing at times, when changing the max line width.
The problem, as far as I can see, is that GlyphString::layout() performs line breaking with approximate calculations based only on xAdvance values.
I don't think we can do any better in layout() because we don't yet know the reordering information.
The only fix I can think of is for newLine() to return an error whenever that occurs and layout() should try again with a different endOffset.
Or maybe there's a simpler way?