Hi. I'm mostly interested in dragonruby as fast prototyping tool, so I have couple of questions:

1) Can it work with popular IDEs, i.e. RubyMine?

2) What graphic formats does it support, beside png? Does it support animations of any kind, or do I have to convert each frame into png and use manually switch over it in tick? How does it affect performance? What about special effects and stuff? Does it have support for texture maps/atlases or do I need to manually cut them myself, too?

3) I don't see it in tutorial. Is it possible to get delta time between ticks (like in Unity), or is it fixed?

> 1) Can it work with popular IDEs, i.e. RubyMine?

It only cares when your Ruby file changes on disk, so it should work with any IDE that can save files.  :)

> What graphic formats does it support, beside png?

jpg, gif, bmp, tga, psd, pic, and pnm.   :)   It does decoding through SDL for bmp files and stb_image for everything else.

> Does it support animations of any kind, or do I have to convert each frame into png and use manually switch over it in tick?

Currently you have to manage this yourself, but we're working on a system to deal with this for you.

> How does it affect performance?

First time you use a graphic, we load it from disk and upload it to a texture on the GPU. Next time you use it, it's already in texture memory and we just draw with it right away.

> Does it have support for texture maps/atlases or do I need to manually cut them myself, too?

You can use a texture atlas like a normal sprite and draw from a subrectangle of it right now. We're not confident that atlases are super important for simple 2D games, so this hasn't been a large priority for us. As an exception to this rule: font glyphs are packed into atlases behind the scenes on first use, because to render a string would be a _lot_ of texture swapping otherwise.

> I don't see it in tutorial. Is it possible to get delta time between ticks (like in Unity), or is it fixed?

It's fixed! The engine runs at 60fps (about 16 milliseconds a frame). We wanted you to not have to spend the effort to do all the math and management for arbitrary frame times.