I just thought I would mention, that made a few more performance fixes with my Linux version (KurtE/Raspberry_Pi · GitHub).
Mainly I sped up the drawing of text when both FG/BG colors are definged. I used some of the inspiration of the ili9341_t3 (Library for Teensy 3/3.1), where I use my writeRect function to output more than one pixel at a time. I generate several rows of data of the character per output.
I updated the graphic test program to have a 2nd draw text test, this one I set the BG color to black. The timings I see are:
ILI9341 Test!
Display Power Mode: 0x9C
MADCTL Mode: 0x48
Pixel Format: 0x5
Image Format: 0x9C
Self Diagnostic: 0x0
Benchmark Time (microseconds)
Screen fill 2769952
Text 2380827
Text 2 385937
So as you can see the version where you set the fg and bg color is considerably faster! I have not done this with the actual Arduino library version as I modified the GFX library to make the drawChar be virtual and so far my Arduino version does not change the actual interface.
Kurt
Edit: made some changes to drawChar when in transparent text mode. Not as fast as other but:
| Text | 1365127 |
| Text 2 | 386748 |