This is used by lcd_puts_scroll_worker() to render the line immediately
instead of waiting for the next scroll tick when only the text was updated.
Previously lcd_puts_scroll_worker() did not render anything in this case
which could lead to visible blinking.
This fixes blinking scrolling lines with dynamic text in the skin engine.
Change-Id: I475bde8c8eb7c92f505e3c5ecf4d32bb90690536
Much of the scrolling work is moved from lcd-bitmap-common to lcd-scroll.c,
a small scroll callback routine remains. This callback can potentially be
overridden by more extensive scrollers.
The callback also gets fed with pixel-based scrolling information, which
finally removes the strict line-based nature of the scroll engine. Along with
this is the change from scroll_stop_viewport_line() to scroll_stop_viewport_rect()
which works on a pixel-based rectangle instead of lines.
The ultimate goal is to move most of the scroll work to apps, which can
much better decide which line decorations to apply etc. This work is laying
the ground work.
Change-Id: I3b2885cf7d8696ddd9253d5a9a73318d3d42831a
Uses a similar technique as lcd_*.c files of #including a common .c file, so
that a unified implementation can be reused for both displays.
Change-Id: I21f6de76df757b093e1a1dff0a4caf96a44fe77e
