shaders

https://retropie.org.uk/docs/Shaders-and-Smoothing/

retroarch.cfg

# Defines a directory where shaders (Cg, CGP, GLSL) are kept for easy access.

# video_shader_dir =

Default Hot Key Binds

Recommend Replace with HotKey+

# Applies next and previous shader in directory.

input_shader_next = "m"

input_shader_prev = "n"

\\spaceinvaders\configs\all\retroarch\shaders

Quick Menu Shaders

Video Shaders

Load Shader Preset

Best Shaders on a1up vertical low res screen.

Retroarch command line

https://docs.libretro.com/guides/shaders/

/opt/retropie/emulators/retroarch/bin/retroarch --set-shader "snes_scanline.glslp" -L <core> <content>

I don't care about core so lets try without.

To Disable automatic shader preset

retroarch --set-shader ""

Launches retroarch in strange UI mode.

Looks in /dev/shm/runcommand.log to set what command line is when launching game

/opt/retropie/emulators/retroarch/bin/retroarch -L /opt/retropie/libretrocores/lr-mame2003/mame2003_libretro.so --config /opt/retropie/configs/mame-libretro/retroarch.cfg "/home/pi/RetroPie/roms/am/mame-libretro/js4way/game.zip" --appendconfig /dev/shm/retroarch.cfg

Starting to think I need the core.

Yes Def need core. Without Core it launch flashing UI on Load Core. So Not optional.

We could get current core from /dev/shm for running game I guess?

/opt/retropie/emulators/retroarch/bin/retroarch --set-shader "snes_scanline.glslp" -L /opt/retropie/libretrocores/lr-mame2003/mame2003_libretro.so --config /opt/retropie/configs/mame-libretro/retroarch.cfg

I don't see update immediately. But might work on next launch?

/opt/retropie/emulators/retroarch/bin/retroarch --set-shader "hq2xwaterpaint.glslp" -L /opt/retropie/libretrocores/lr-mame2003/mame2003_libretro.so --config /opt/retropie/configs/mame-libretro/retroarch.cfg

Nop nothing

Think it needs content ie rom, etc.

So either we change the launcher to accept a configurable shader command. OR we figure out how global presets work. Maybe we can just set the global preset to what we want and be done with it. This won't be immediate but it will work on next launch which I think at this point is the best we can do.

Yes, with the shader you want active, just enter the shader menu, select ”save“, and then “save global preset“. The shader will now be default for all cores.

https://github.com/libretro/RetroArch/issues/5398

Global shader preset is saved here

\\SpaceInvaders\configs\all\retroarch\config\global.glslp

/opt/retropie/configs/all/retroarch/config/global.glslp

So from code we just replace with what we want and launch.

Watch shader files for changes.

video_shader_watch_files I think setting this to true will causes it to update on global replace.