This structure contains a header and an array of rectangles that make up a region. The rectangles are sorted top to bottom, left to right. They do not overlap.
Specifies a RGNDATAHEADER structure.
The members of this structure specify the type of region (whether it is rectangular or trapezoidal), the number of rectangles that make up the region, the size of the buffer that contains the rectangle structures, and so on.
Specifies an arbitrary-size buffer that contains the RECT structures that make up the region.