Remove legacy changes for double buffered SPI
Eliminate unecessary ESP32 SPI read/modify write
Eliminate two stage control bit changes (may impact some diplays with
setup/hold timing and show ESP32 hardware register bug?)
Add single register write for CS and DC command
Make setAddrWindow smarter (as used in previous AVR library)
Improve compatibility with GFX sketches
Re-arrange comments slightly to improve positioning
The library supported 240x240 ST7789 displays only which require an 80
pixel offset in rotation 2 and 3
The library now also supports the 240x320 display which has a different
RGB colour order.
This is stage one of support for ePaper displays from Waveshare.
Examples for 1 bit per pixel Sprites and 2 or 3 colour ePaper displays
to follow soon.
Bodmer