How to capture desktop screen and draw in on window in linux

Question

I am new to linux and i need port my windows program to linux and need help at the following.

1. I need to capture the screen.
2. I need to create a window without borders and title which covers the whole screen.
3. I need to draw the captures screen on that window.
4. I need to alpha blend a black picture over the window at XX% opacity.

All this was done easily with GetDC(NULL), BitBlt() and AlphaBlend() on windows.

Linux looks very hard when coming to such simple programs to do.

Answer 1

For Linux; you can always look at the source for scrot -- a small and simple screenshot program.