On Friday 22 November 2002 6:38 pm, Carl Worth wrote: | On Nov 21, Owen Taylor wrote: | > I have some general reservations about using a postscript-type API. I | > believe that on the low end, such an API is rather hard for | > programmers to use -- they want "draw_circle", "draw_rectangle" type | > primitives. | | A toolkit built around Xr could easily add higher-level "primitives" | desired by application developers. That said, Xr is still far from | complete, but I'm cautious about putting too much into it. The current | plan is for Xr to have at least enough functionality to support the | rendering needs of PDF 1.4.
You can draw circle using 2 Bezier paths, or better 4 paths, if we follow Adobe PostScript convention of "having end points for curve segments at every extreme point". AFAIK every circle you draw in some font editor becomes 4-path object when saved to file (or when you release LMB). BTW: does Xr/Xc support dashed/dotted lines? | > - Ability to draw with glyph codepoints instead of characters | > - Ability to draw with offsets for individual characters in the | > string - Ability to get metrics for characters and strings | | Right. This is all obviously missing. | | I'd like to avoid a huge explosion in the font rendering APIs, and as | much as possible I'd like to have intuitively named functions. I don't | mind if the Xr API does not match Xft. | | The plan is to support only the UTF8 encoding. So, can we drop all of | the 8/16/32/Utf8 distinctions from Xft? What about UTF-16? I think it's required to display, say, Chinese glyphs. | | If so, we could have the following functions for rendering characters | or glyph codepoints without explicit offsets: | | XrShowText | XrShowGlyphs | | The names can be changed if people have strong preferences. | /Show/Draw/ and /Text/String/ are obvious opportunities. ok, if we are talking about text rendering now: pls consider using kerning values. Kerning data is accessible from FreeType API, so this should not be a problem. Also, we should have support for new rendering modes added to FreeType-2.1.3. (FT-2.1.3 has been released few days ago) | | Beyond that, we need variations of each that allow explicit | offsets. I'm inclined to have a single structure for storing the | offsets for either a string or glyphs rather than separate | CharSpec/GlyphSpec structures ala Xft. Maybe something like: | | XrShowTextOffsets | XrShowGlyphsOffsets | | each accepting an array of XPointDouble? | | Also, is the Xft model sufficient for application developers? | Postscript provides a substantial number of different variations for | adjusting offsets. Are there variations there that might be important? | I guess we can always add things later as needed. | [...] | | -Carl -- Vadim Plessky SVG Icons http://svgicons.sourceforge.net My KDE page http://kde2.newmail.ru (English) KDE mini-Themes http://kde2.newmail.ru/themes/ _______________________________________________ Render mailing list [EMAIL PROTECTED] http://XFree86.Org/mailman/listinfo/render
