Performance degradation for label

[kmatch98]

#61

Performance degradation was noted by @kevinjwalters

[FoamyGuy]

Thank you for sharing that example code Kevin! I am trying to put together a suite of tests to run whenever display_text is updated, I will add this one.

I am assuming the performance hit is due creating the bitmap and tilegrids, if so, I think we are likely stuck with it at least for custom fonts, since the bitmap is required to make the background look correct.

Something we could look into is adding logic that will revert to the previous background strategy when the default font is used instead of the newer bitmap+tilegrid. I think that should get the performance back to how it was for default font labels.

[kmatch98]

Agreed on your comment about treating the builtin font differently. However when I first looked into it I couldn’t figure out how to detect which font type (builtin vs BDF lodes). I think that is the key to unlocking the ability to treat each differently.

[FoamyGuy]

I was able to tinker with this for a bit tonight. I think we can use the font property and test against terminalio.FONT. This example seems to print the correct value for both types of fonts:

import board
import terminalio
from adafruit_display_text import label
from adafruit_bitmap_font import bitmap_font

#font = bitmap_font.load_font("/Helvetica-Bold-16.bdf")
font = terminalio.FONT

text = "Hello world"
text_area = label.Label(font, text=text)
text_area.x = 10
text_area.y = 10
board.DISPLAY.show(text_area)

print(text_area.font == terminalio.FONT)
while True:
    pass

[kmatch98]

Looks like good progress. To me it’s a little odd that there is a separate class for type BuiltInFont https://circuitpython.readthedocs.io/en/5.3.x/shared-bindings/fontio/BuiltinFont.html

Does anyone know if there will ever be more BuiltInFont other than terminalio.FONT? If so does this need to be generic for all BuiltInFonts?

My guess is that your code will most cases but wanted to document this here.

[FoamyGuy]

That is a good question. I don't know whether there will ever be others. I do think that some devices have a different built-in font, but it's still referenced with terminalio.FONT I think.

Just in case we could make this a little more generic by checking the type like this:

print(isinstance(text_area.font, fontio.BuiltinFont))

This one seems to be working as well when substituted in the above example.

[kmatch98]

Some feedback from @tannewt regarding display performance here:
#71

[tannewt]

BuiltInFont exists to make it easier to build in a font. If it was python, then it'd be trickier to have the object within the core build itself. It's mean to have the same API as other font classes and be treated the same.

I wouldn't expect more than one to exist in a build because they take a good chunk of space.

[kmatch98]

The original issue that was linked was closed, so closing this issue also.