I whipped this up in about a half hour at the April Cleveland Game Developers meeting. It’s a very simple, but useful function which draws a Health Halo [aka “health meter”, “life bar”, etc.] above the sprite of any Game Maker object that has member variables named life and maxlife.
Health Halos are very common in multiplayer and RealTime Strategy (RTS) games.
As always, the source is freely available, along with a demo project. Download the extension package .zip file from the Releases page