What parameters I can pass to this function?

I found a function

 function RotateBitmap(var hDIB: HGlobal;
 radang: Double; clrBack: TColor): Boolean;

that rotates an image. But I don't know how to call this function. What parameters I can pass to this function. I don't know how 开发者_JS百科to use this func at all.

Judging by the code presented hDIB is a pointer to a single memory block containing 2 structures - BitmapInfo and bitmap's pixel array. You can obtain these structures from TBitmap using GetDIBSizes and GetDIB functions.

If you are interested in bitmap transformations you can follow David's advice and try graphics32