How to use shady with ledcat

I use shady with rpi-rgb-led-matrix/ledcat to display animations on my LED Cube.

shady is a tool to render GLSL shaders.
ledcat is a tool to control lots of LED’s over lots of protocols.
ledcat.cc is a script within the rpi-rgb-led-matrix library, used to display animations on RGB-LED panels.

shady

Follow the instructions given in How to install shady in Raspberry Pi4.

polyfloyd/ledcat :

Install :

wget https://github.com/polyfloyd/ledcat/releases/download/v0.2.0/ledcat-armv7-unknown-linux-gnueabihf.tar.gz
tar -xzf ledcat-armv7-unknown-linux-gnueabihf.tar.gz
./ledcat

Test :

see https://github.com/polyfloyd/shady/issues/14

export LEDCAT_GEOMETRY=64x64
export EGL_PLATFORM=surfaceless
export MESA_GL_VERSION_OVERRIDE=3.3

shady -i example.glsl -ofmt rgb24 -g 64x64 -f 20 | ledcat -f 20 show

Note : in the above example, the -f 20 parameter must be specified for both commands.

# GPIO for Adafruit RGB Bonnet : 
shady -i example.glsl -ofmt rgb24 -g 64x64 \
    | sudo ledcat --geometry 64x64 hub75 --level-select 22,26,27,20,24 \
           --red 5,12 --green 13,16 --blue 6,23 --clock 17 --latch 21 --output-enable 4

shady -i example.glsl -g 64x64 -f 20 -ofmt rgb24 \
    | sudo ledcat --led-rows=64 --led-cols=64 --led-slowdown-gpio=4 --led-show-refresh \
           --led-pwm-bits=11 --led-pwm-lsb-nanoseconds=100 --led-brightness=80 --led-rgb-sequence RBG

rpi-rgb-led-matrix/ledcat.cc

Install :

git clone https://github.com/hzeller/rpi-rgb-led-matrix.git
cd rpi-rgb-led-matrix/
make

Test :

cd examples-api-use/
sudo ./demo --led-rows=64 --led-cols=64 --led-gpio-mapping=adafruit-hat --led-slowdown-gpio=5 -D 0
cat /dev/random | sudo ./ledcat --led-rows=64 --led-cols=64 --led-gpio-mapping=adafruit-hat --led-slowdown-gpio=5

with shady :

shady -ofmt rgb24 -g 64x64 -f 20 -i ~/projects/shady/shaders/example.glsl \
    | sudo ./ledcat --led-rows=64 --led-cols=64 --led-gpio-mapping=adafruit-hat --led-slowdown-gpio=5

note: param -f 20 is mandatory