This asset has only been tested with GameMaker: Studio 1.
Download demo: https://1drv.ms/u/s!AppH38QcoEBfiKVDIoupeQEdO57wLw
Forum thread: https://forum.yoyogames.com/index.php?threads/2d-block-lighting-free.3297/
This asset lets you implement 2D block lighting for your game.
Although the included example also visualizes blocks, this asset's focus is on the lighting specifically (for block visualization I recommend my other asset: https://marketplace.yoyogames.com/assets/2211/autotiling-tilemap-shaders).
Remember to read the asset's EULA:
End User Licence Agreement (EULA).
Much easier to implement. Much more organized. Better commenting. Modular design.