vurflex.blogg.se - Inkscape text

A chunk is an unbroken section of a line.

Can be from 'x' and 'y' attributes or calculated from shape and ascender height.

Locate start text insertion point (baseline of line of text).

Must handle SVG kerning, text-length attributes, white-space (spaces, tabs, line-returns), etc.

Layout items in allocated space, determining glyph positions.

Use a specialized iterator to walk through maps.

Create Character, Glyph, Cluster mappings.

Either Pango or HarfBuzz can be used (Pango uses HarfBuzz under the hood).

Shape the Pango items to determine which glyphs with positions should be used to render the text.

The designated font may be missing all the glyphs needed to render the text Pango will find the best alternative font that has the missing glyphs and create an item for them.

Use Pango to itemize spans: This breaks spans into smaller pieces based on font, script direction (right-to-left, left-to-right), etc.

A list of shapes: Possibly an infinitely long line.

A list of spans: Text with unique style and/or positioning attributes.(Bitmap glyphs are still supported inside OpenType fonts.) I'm guessing that bitmap fonts haven't worked for a long time. Pango has dropped support for bitmap fonts (and type 1 fonts) with Pango 1.44. variable fonts) aren't implemented for PANGO_WIN32. The use of USE_PANGO_WIN32 (directly using Window fonts) was disabled in 2011. This font hash includes "gravity" (glyph orientation, important for vertical text where, for example, the letter 'A' can be rendered upright or sideways) which is missing in our custom hash. Pango has a built in hash which we should probably use instead. Ī number of changes we should make to Inkscape's code even if it is not completely rewritten.Ĭurrently Inkscape uses a custom hash of the Pango Font descriptor to index fonts in a font map. Pango and Cairo are poorly maintained at the moment. HarfBuzz is under active development and is used by many major pieces of software. The boundaries between these libraries is somewhat murky and often one can do the same things using routines from different libraries. Pango: Determines best fonts to render text for given style and characters.HarfBuzz: Converts characters to glyphs (i.e.Our software stack relies on the FreeType, HarfBuzz, Pango, and Cairo libraries for rendering text. This page is the result of an on-going process of planning a refactor of Inkscape's text handling.

1 A summary of observations about text rendering!Ī summary of observations about text rendering!.