While "set" is a tad strong (there's just the one component for now), I
had missed the changes when adding ECS systems. Fixes the segfault at
the end of demo1 (ie, when any center text is printed).
Instead of creating new entities for the text views. This approximately
halves the number of entities required to display flowed text, but also
tests the ability to have an entity in multiple hierarchies (the goal of
the ECS component and system changes).
While this does require an extra call after registering components, it
allows for multiple component sets (ie, sub-systems) to be registered
before the component pools are created. The base id for the registered
component set is returned so it can be passed to the subsystem as
needed.
This means that the component id used for hierarchy references must be
passed to Hierarchy_New and Hierarchy_Copy, but does all an entity to
have more than one hierarchy, which is useful for canvases (hierarchies
of views) in the 3d world (the canvas root would have a 3d hierarchy
reference and a 2d (view) hierarchy reference).
The main problem was the confusion about the coordinates within a single
glyph, and thus the glyphs position within the view's box. With this,
flowed text works fairly well except for some issues with spacing
between lines (which I think is due to the flow code not having been
tested with offset boxes).
Font cannot be overridden yet, but script attributes (language, script
type, direction) and features can be set at all three levels in a
passage. Attributes on the root level act as defaults for the paragraph
and word levels, and paragraph attributes act as defaults for the word
level.
Passage_Delete needs to check if the hierarchy is valid as no text may
have been added, which results in a null pointer for the hierarchy.
Text shaping needs to set language etc every time it resets the buffer.
This causes some problems with linking if libQFgui is linked with
libQFrenderer (which is necessary in the long run), but it seems
everything gets away with it for now (which, tbh, I don't like).
And add a function to process a passage into a set of views with glyphs.
The views can be flowed: they have flow gravity and their sizes set to
contain all the glyphs within each view (nominally, words). Nothing is
tested yet, and font rendering is currently broken completely.
