Most of what it does is create a list of draw commands (as a class) and populates the details of each command. Only the regular lines are drawn currently, which was to verify I had the right structure. In this case the draw is multiplying coordinates rather than mapping to 160x200 and doubling up from there.
You might remember from my web site back in the late 90s that I was attempting to draw AGI pictures in hi-res. The main problem I had was with the fills. It's certainly possible to draw the vector graphics in a higher resolution and to have those crisper lines, but the fills tend not to work most of the time. There are multiple reasons for this. One of these in the line drawing algorithm. There are different algorithms for drawing lines that place pixels in different places, and even if you get the algorithm the same, drawing the lines at a higher resolution ends up putting pixels in places that are not compatible with where the fills points are placed. Sometimes in AGI pictures, a single pixel is placed to plug a gap in a area that then gets filled. Drawing that at a higher res obviously won't plug that gap, so the fill spills in to the neighbouring area. Fills sometimes also land on top of lines in hi-res, since I've noticed that fill points are sometimes placed right next to a line, so if the line points differ slightly, the fill might land on a line pixel.
You've also got a problem with the "dithering" effect that some games use, where they draw diagonal lines. Doing that at hi-res needs some kind of intelligence to recognise that its dithering and to scale that up. You can't just draw the lines.
And obviously the "brush" tool isn't going to work at high res, unless you replace them with a higher res pattern.
I've had lots of ideas on how to do it better since my attempts in the 90s. I'd like to try again at some point.
I've never tried it, but I read somewhere that SCUMMVM supported a hi-res AGI mode. Is this true? Has anyone tried it?