On 12-Feb-2014 15:03, Krzysztof Kosiński wrote:
The situation could be improved by using this solution, especially since the SP classes are now C++: http://en.wikipedia.org/wiki/Visitor_pattern
This would require some rewriting in the LaTeX and EMF renderers. On the other hand, adding new output formats would become much much easier after that.
Definitely wait until after the current release cycle.
The only complication I see is that EMF/WMF text output performs some strange processing in Layout-TNG-Output in Layout::print(). Depending on output settings, it may convert text from other fonts to Symbol or Wingdings font there (because, for instance, some programs that read EMF/WMF know how to process Greek characters in Symbol font, but not in Arial font), and since EMF text records demand x,y kerning information, that is extracted from the glyph array and smuggled via a bletcherous hack to the final text output. (The information is converted to a text string and stored after the normal output text's null byte string terminator.) Cairo output does not go through this routine. Instead it passes through the somewhat similar Layout::showGlyphs().
What happens below these is quite different. The downward paths are:
sp_print_text(ctx, smuggle_string, g_pos, text_source->style);
vs.
ctx->renderGlyphtext(span.font->pFont, font_matrix, glyphtext, style);
The first passes the position (g_pos) and the text (UTF plus the smuggled kerning information), whereas the second passes a bunch of font information along with an array of glyphs. Basically one is for "text string goes here" output, and the other for "draw these glyphs" output. I suppose in the fused output the common downward routine could just pass all of this information, and the called routine would use whichever was appropriate. That would be better in at least one way - the kerning information could be extracted in (new) sp_print_text, which would eliminate the need to smuggle it.
Regards,
David Mathog mathog@...1176... Manager, Sequence Analysis Facility, Biology Division, Caltech