There are a few things that I miss from MS Paint that I think Paint.NET could do much better, and there are a couple things I think could be improved. As a programmer, I can think of ways to do this, but as I only know C# and not the C++ needed to create plugins, I've fallen short. Been using the software for a while and this is what would make it perfect, in my opinion:
- Spray Paint tool: Or air brush or whatever you might call it. I'm not up on the jargon, but if Paintbrush can do it in the glory days of 256 color (and now I feel old XD), working in 32-bit color can only improve it.
- Ability to determine points on a spline: I sprite, so when dealing with the Line/Curve tool, it can be annoying to adjust straight like it would be with just two points. Likewise, when I'm using it to digitally ink my hand drawings, four points is often just not enough. As a programmer, I really don't see how setting the number of points as a variable should be difficult to implement, allowing the end user to change the number based on need. Just stick a floor at two and a ceiling at something reasonable and off you go. The math to determine initial placement isn't all that hard. I can probably come up with a formula given the time and freedom from pressing amounts of work (like I currently have as a college student nearing completion) to help place them if they're added to an existing curve based on some sort of weighting system.
- Paletting functions would also be great for spriting. Currently, I use Graphics Gale to create a palette for my sprite, then eye drop it and work in Paint.NET. It would be totally great to be able to define a user palette and work from there. Otherwise, you're messing up the default palette and you might actually want to use that for other things. By allowing you to create palette files, you could also apply them to sprites easily for recolors and it would even allow for interesting possibilities for me as a programmer working on a game. Currently, the closest I have to this is a "Selective Palette" plugin, which simply bumps pixels over to a palette you've already defined with the plugin. It doesn't support palette-swapping, though, or actually working in a fixed palette. If nothing else, allowing you to switch out palettes in the existing window would be great.
I think with these few features, the product could blow the competition out of the water. Or at least make a good showing in versatility.