Silently accepting mismatched color tuples.

[caternuson]

Should we be silently accepting color tuples that don't match pixel order?
Give an RGB a 4 tuple, no errors:

Adafruit CircuitPython 3.0.3 on 2018-10-10; Adafruit Gemma M0 with samd21e18
>>> import board, neopixel
>>> pixels = neopixel.NeoPixel(board.A2, 8, pixel_order=neopixel.RGB)
>>> pixels[0] = (255,0,0,255)
>>> pixels.fill((255,0,0,255))

Give a RGBW a 3 tuple, no errors:

Adafruit CircuitPython 3.0.3 on 2018-10-10; Adafruit Gemma M0 with samd21e18
>>> import board, neopixel
>>> pixels = neopixel.NeoPixel(board.A2, 8, pixel_order=neopixel.RGBW)
>>> pixels[0] = (255,0,0)
>>> pixels.fill((255,0,0))

In both cases, all zeros get sent out instead. See here:
https://github.com/adafruit/Adafruit_CircuitPython_NeoPixel/blob/master/neopixel.py#L145

[kattni]

No, we should not. Seems like having that be caught and return an error would be super helpful.

[caternuson]

The possible combinations can be summarized as:

Input	RGB NeoPixels	RGBW NeoPixels
24 bit int	OK	automagic
32 bit int	?	?
3 tuple	OK	?
4 tuple	?	OK

We need to decide what the behavior should be for the ?. The OK entries have obvious behavior. Nothing is currently done for 32 bit int, adding it here for completeness.

[jerryneedell]

its a bit hard to distinguish a 32 bit int from a 24 bit int with the 8 upper bit 0.
0x00123456
vs
0x123456

[jerryneedell]

so I guess you just want to reject a value with the upper nibble set for an RGB
that is
0xXX123456
will be rejected if XX non zero for the RGB case.
Is that what you have in mind?

[jerryneedell]

never mind -- clearly I'm confused about how the ints are used.
apparently the upper 8 bits are never used. is that correct?
Should they be used for an RGBW to set W ?

[jerryneedell]

Discussed in weekly -- plan forward:
Throw ValueError if 4-tuple fed to RGB
Throw ValueError if any bits above bit 23 are set in integer mode

If 3-tuple sent to RGBW -- set RGB values.

[caternuson]

Yep. In table form:

Input	RGB NeoPixels	RGBW NeoPixels
24 bit int	OK	automagic
>24bit int	ValueError	ValueError
3 tuple	OK	W=0
4 tuple	ValueError	OK

[jerryneedell]

Thanks! -- hopefully this is accomplished by #37 Let me know if I missed something.

[caternuson]

Closing. Fixed by #37. Thanks @jerryneedell.

Possible future solution - make things super simple here, just support a 3 or 4 tuple. Move all the logic and other things to some external helper that can take various inputs/flags/etc and return the required 3 or 4 tuple.