I'm using aforementioned gdi function to display some data into window's client area (part of memory where i actually write some data like lines etc..), i do not use stretching or such thinks, just plain copy from data in form of bitmap.
I use it A LOT, it handles all drawing to client area, and i encountered problem: sometimes it does neither fail nor draw anything: input params are proper, but it returns 0 as number of lines drawn. Weird is that it happens seemingly without any triggering effect, if i force a window to repaint, it sometimes works again, sometimes not; when i resize window, it works again... I have no clue why might it fail and so far found no evidence of errors in my own code (it actually WORKS almost all the time without errors or problems and/even after such a draw error).
I still hope i'll find error within the code, but it is unlikely, so i started to 'blame' the function itself. May it be kind of 'overload'?
I tried it only on WinXP (Pro) systems so far.