Well I have kind of been letting this code sit for a while, not looked at it as of late, then this week decided to have another play with it, kind of hoping I can put it to bed.
So I have not started to use Ninians sprite sheet, the sheet is full of alphas, so instead of getting them off the sheet and then just sending them to the screen, set the base colour of the sprite then multiply its alpha by the RGB returned from the sprite sheet. This I think gives a more natural cloud look. I still have some performance issues, but have managed to speed up the draw order sort and that has helped a little. I have also put in some terrain so you have a point of reference, was a bit odd just looking at clouds hanging there in the sky..
I still have tones I want to do with this yet. I think the next thing will be imposters, then an editor so you can create a cloud field or set of clouds and be able to save them to disk and re use them as an when you like. Naturally more optimizations and some lighting in the shader.
Hop you like the clip, ratings, and comments are welcome as ever.