In preparation for using Shaper with an io.Reader, rework the API to not refer
to strings. In particular, introduce Glyph for holding the rune in addition to
the advance. For fast traversing of the underlying text, add Len to Line with
the UTF8 length.
Layout is a useless wrapper around []Line; remove it while we're
here.
Signed-off-by: Elias Naur <mail@eliasnaur.com>
MacroOp is about to lose the ability to run a different operation list
than the one it was recorded on. Text shape caches rely on that property,
and must use the new CallOp operation added for purpose.
Signed-off-by: Elias Naur <mail@eliasnaur.com>
Opentype parsing, layout and shaping will be used by subpackages to package
font. Move the opentype package accordingly.
Remove the Must helper function; programs will no longer use the opentype
package in the normal case.
Signed-off-by: Elias Naur <mail@eliasnaur.com>
Elias Naur