Add USE_LCD_DOUBLE_BUFFERING option

[dbuezas]

Description

Adds an option to enable double buffering (plus only sending changed screen areas) for SSD1309 LCDs.
Follow up to: MarlinFirmware/U8glib-HAL#31

Requirements

Requires SSD1309 LCD

Benefits

Faster LCD updates (particularly noticeable when using software i2c)

Configurations

Related Issues

[dbuezas]

After ~2 months of use, I haven't noted any issues with this, and the LCD is extremely snappy.
Please let me know if there is anything pending on my side :)

[dbuezas]

Anything else pending?

This allows using a new mode already merged in U8glib-HAL that improves refresh rate quite a bit. It is optional and disabled by default.
More details in the U8glib PR linked in the PR description above.

[thisiskeithb]

Anything else pending?

95 other PRs and all kinds of work to fix up 2.1.2.2 as well as prep 2.1.3 for release.

Please have some patience.

[dbuezas]

Sorry for that, I wondered if I had missed something else.

Thanks a lot for your continuous work in this amazing project!

[dbuezas]

In case the utility of this got lost

The double buffered method this exposes drastically reduces cpu time spent talking to the LCD:

• Send buffer at once instead of page by page: Row by row updates (default method) are actually visible and the full screen update takes a lot longer to complete, this option makes a big difference.
• Send only changed pages (rows): Reduces communication a lot, particularly in the status screen.
• Out of those pages, send only changed columns: Further reduces communication considerably.

The end result is up to 95% faster/less data transferred to the display.

Back then I made this quick demo where all pixels that don't need to be sent are white (inverted color to be precise):

285644705-6f61276f-8e69-4895-a4ba-63918e46da5b.mp4