Blog post with details and pictures: http://marc.merlins.org/perso/arduino/post_2018-04-23_FastLED_NeoMatrix-library_-how-to-do-Matrices-with-FastLED-and-Adafruit_GFX.html
Adafruit_GFX and FastLED-compatible library for NeoPixel matrices and grids. Controls single and tiled NeoPixel displays.
This library requires FastLED and Adafruit_GFX libraries as well as this base class library:
This code was taken from Adafruit_NeoMatrix and adapted to work with the more powerful FastLED library. The reasons for using FastLED instead of Adafruit::Neopixel as a backend, include:
How to use the API? It's very close to Adafruit_NeoMatrix, to see an example, you can compare
https://github.com/adafruit/Adafruit_NeoMatrix/blob/master/examples/MatrixGFXDemo/MatrixGFXDemo.ino
with
https://github.com/marcmerlin/FastLED_NeoMatrix/blob/master/examples/MatrixGFXDemo/MatrixGFXDemo.ino
You can find a lot of demo code here:
https://github.com/marcmerlin/FastLED_NeoMatrix_SmartMatrix_LEDMatrix_GFX_Demos as well as
a big integrated demo here: https://github.com/marcmerlin/NeoMatrix-FastLED-IR
Most my demos rely on this big file that lets you configure your panel(s) type and size and have it work with all the demo code. It allows using the exact same code on neopixel arrays, rgbpanels, tft screens, and even your linux computer.
This FastLED_NeoMatrix requires:
See Adafruit's NeoMatrix description, which this lib is fully compatible, with: https://learn.adafruit.com/adafruit-neopixel-uberguide/neomatrix-library
If you have a custom made design where the pixels are not in a rectangular pattern, you need to provide a myRemapFn which is then fed to the matrix with "matrix->setRemapFunction(myRemapFn)"
See https://github.com/marcmerlin/FastLED_NeoMatrix/issues/6 for an example.
Video demo: https://www.youtube.com/watch?v=tU_wkrrv_4A