Add address_little_endian for epaper displays with little endian
(low byte first) addresses.
Also clears allocated display and display bus memory so it has a
known state. The acep member wasn't always set so it varied
accidentally.
Fixes#7560. May fix#7778. Fixes#5119.
@cwalther determined that for boards with 2 displays (monster m4sk),
start_terminal would be called for each one, leaking supervisor heap
entries.
Determine, by comparing addresses, whether the display being acted on
is the first display (number zero) and do (or do not) call start_terminal.
stop_terminal can safely be called multiple times, so there's no need
to guard against calling it more than once.
Slight behavioral change: The terminal size would follow the displays[0]
size, not the displays[1] size
An RGBMatrix has no bus and no bus_free method. It is always possible
to refresh the display.
This was not a problem before, but the fix I suggested (#3449) added
a call to core_bus_free when a FramebufferDisplay was being refreshed.
This was not caught during testing.
This is a band-aid fix and it brings to light a second problem in which
a SharpDisplay + FrameBuffer will not have a 'bus' object, and yet does
operate using a shared SPI bus. This kind of display will need a
"bus-free" like function to be added, or it can have problems like
#3309.
vectorio builds on m4 express feather
Concrete shapes are composed into a VectorShape which is put into a displayio Group for display.
VectorShape provides transpose and x/y positioning for shape implementations.
Included Shapes:
* Circle
- A radius; Circle is positioned at its axis in the VectorShape.
- You can freely modify the radius to grow and shrink the circle in-place.
* Polygon
- An ordered list of points.
- Beteween each successive point an edge is inferred. A final edge closing the shape is inferred between the last
point and the first point.
- You can modify the points in a Polygon. The points' coordinate system is relative to (0, 0) so if you'd like a
top-center justified 10x20 rectangle you can do points [(-5, 0), (5, 0), (5, 20), (0, 20)] and your VectorShape
x and y properties will position the rectangle relative to its top center point
* Rectangle
A width and a height.
This code is shared by most parts, except where not all the #ifdefs
inside the tick function were present in all ports. This mostly would
have broken gamepad tick support on non-samd ports.
The "ms32" and "ms64" variants of the tick functions are introduced
because there is no 64-bit atomic read. Disabling interrupts avoids
a low probability bug where milliseconds could be off by ~49.5 days
once every ~49.5 days (2^32 ms).
Avoiding disabling interrupts when only the low 32 bits are needed is a minor
optimization.
Testing performed: on metro m4 express, USB still works and
time.monotonic_ns() still counts up
