Had the most odd issue, with the Pi code, try as I might I could not get the bugger to display any texture which was created my malloc, even though I assume it was all 0 and therefore transparent, when I moved data into it, it should have become visible. Finally I discovered that if I used memset to put data in there the textures became visible....then later became visible anyway :(
So I was probably doing a combination of little things wrong until I hit the right things
But no matter, I now have a screen sized texture, the size of which I can control, stretched over a full screen image.. :D
I can make a start proper now on the projects and get things moving on the 1st 3 projects which need this rather crappy code.
time for bed