bitmaptools.draw_polygon: Change Coordinate Data Type to Integer List

[CedarGroveStudios]

To be able to easily use the entire polygon x-y coordinate range, please consider changing from a ReadableBuffer data type to an integer list.

From #7471:

In my application, bitmaptools.draw_polygon would be very useful if it accepted a large (>200) list of integers instead of a ReadableBuffer object. For now, the application is iterating through a list and using draw_line instead.
The simpletest example shows converting a list to a byte array, but that doesn't allow coordinate values larger than 127. Using struct or a ulab.numpy array allows larger values up to 16-bits. However, ulab isn't available for all boards and struct is only practical for lists of just a few points.
A side benefit of changing the coordinate data type to integer would be UI consistency with other bitmaptool drawn objects. I'll open a new issue that specifically asks for coordinate integer lists.
BTW, being able to leave the polygon open is a big plus when plotting waveshapes and formulae, cartesian-style.

[tannewt]

I think you want array.array. You can give it integer size and it looks like the bitmaptools code will respect it. https://docs.python.org/3/library/array.html

[CedarGroveStudios]

Indeed it was respected. It also dropped memory usage dramatically and improved performance slightly. Perhaps the simpletest code should be changed from byte() to array.array() to help folks like me.

You helped me to peel back another layer of the Python onion. I have some other code that will likely benefit, as well.

Thank you!

[dhalbert]

Maybe ReadableBuffer is not the clearest type annotation. The documentation should explain that 16-bit values are possible.

[CedarGroveStudios]

I first encountered the ReadableBuffer data type when working with synthio.waveform objects -- and was initially confused. The examples and related learning guide code used dtype=ulab.numpy.int16 which helped me to understand that those were int16 arrays as well.