The Rendering Pipeline
The Pango rendering pipeline takes a string of Unicode characters, converts them it into glyphs, and renders them on some output medium. This section describes the various stages of this pipeline and the APIs that implement them.
- Itemization
- breaks a piece of text into segments with consistent direction and shaping properies. Among other things, this determines which font to use for each character. Use pango_itemize() or pango_itemize_with_base_dir() to itemize text.
- Shaping
- converts characters into glyphs. Use pango_shape(), pango_shape_full() or pango_shape_with_flags() to shape text.
- Line Breaking
- determines where line breaks should be inserted into a sequence of glyphs.
The function pango_break() determines possible line breaks. The actual line
breaking is done by
PangoLayout
. - Justification
- adjusts inter-word spacing to form lines of even length. This is done by
PangoLayout
. - Rendering
- takes a string of positioned glyphs, and renders them onto a surface. This is
accomplished by a
PangoRenderer
object. The functions pango_cairo_show_glyph_string() and pango_cairo_show_layout() use aPangoRenderer
to draw text onto a cairo surface.