Once I nail this down though, I imagine making a level designer app wouldn't be so hard. Just something that lets you click grid spaces on (travel) or off (no travel) and returns the gridlayout$ value so you can copy and paste it into the actual game.
I started one of those awhile ago. I was gonna have a sprite pallet on the right side of the screen where you could click on a sprite to copy it and click a grid space to paste it. I was gonna allow the player to set each sprite's collision class so that you could hold dozens of classes, instead of just "wall" and "empty". ( for example, you could have "water" and "thorns" and so on) I realized 2 important things however:
1: GM can't handle the required amount of sprites to work the engine.
2: Seeing as how the engine couldn't actually save the
picture, only the gridlayout$ value to a text file so that I could copy and paste it into the editor, I wouldn't actually be saving any time at all. I'm much faster just typing 1's and 0's in the editor.