What's this for? Designing hit boxes? How do I check what texture has been used for a sprite?

if you use spclip 0,0,200,240 then sprites out of this area don't be displayed.

try bgclip too

Oh, okay. Isn't there a way to change the thickness of a line made with GLINE?

no. try with two lines parallels one close to the other. or experimen with "gtri"... i think i can create a function to do that.

¡¡¡ I made it !!!

key in the screenshot. program "lin"