61.4.16 Regions

Region functions create, alter, and retrieve information about regions. A region is an elliptical or polygonal area within a window that can be filled with graphical output. An application uses these functions in conjunction with the clipping functions to create clipping regions. For more information about clipping functions, see “Clipping Functions.” The following list briefly describes each region function:

Function Description

CombineRgn Combines two existing regions into a new region
CreateEllipticRgn Creates an elliptical region
CreateEllipticRgnIndirect Creates an elliptical region
CreatePolygonRgn Creates a polygonal region
CreatePolyPolygonRgn Creates a region consisting of a series of closed polygons that are filled as though they were a single polygon
CreateRectRgn Creates a rectangular region
CreateRectRgnIndirect Creates a rectangular region
CreateRoundRectRgn Creates a rounded rectangular region
EqualRgn Determines whether two regions are identical
FillRgn Fills the given region with a brush pattern
FloodFill Fills the display surface within a border
FrameRgn Draws a border for a given region
GetPolyFillMode Retrieves the current polygon-filling mode
GetRgnBox Retrieves the coordinates of the bounding rectangle of a region
InvertRgn Inverts the colors in a region
OffsetRgn Moves the given region
PaintRgn Fills the region with the selected brush pattern
PtInRegion Tests whether a point is within a region
RectInRegion Tests whether any part of a rectangle is within a region
SetPolyFillMode Sets the polygon-filling mode
SetRectRgn Creates a rectangular region