Module Hugin_text
Rich text and its layout.
Text is the rich text that labels, titles and legend entries are made of, and Text.Layout sets a text in a list of faces as the glyph runs (Hugin_font.Run) that pictures draw, measuring it without drawing. The library depends on fonts, not on pictures: a caller draws a layout's runs in whatever it draws with.
Lengths follow the geometry conventions: the plane is y-down.