RAD Studio VCL Reference
Classes.InvalidPoint Function

Indicates whether a specified point is equal to (-1,-1).

function InvalidPoint(X: Integer; Y: Integer): Boolean; overload;
function InvalidPoint(const At: TPoint): Boolean; overload;
function InvalidPoint(const At: TSmallPoint): Boolean; overload;
Boolean InvalidPoint(int X, int Y);
Boolean InvalidPoint(const TPoint At);
Boolean InvalidPoint(const TSmallPoint At);

The point (-1,-1) is often used, by convention, to represent an invalid set of coordinates. This convention is often employed by Windows API functionsand by several Linux utilities. When working with other code that uses this convention, use InvalidPoint to identify coordinate values that are invalid. 

At is the point to examine. 

X and Y identify the point by giving the X and Y coordinates respectively. 

InvalidPoint returns true if the specified point is (-1,-1), false otherwise. 


Copyright(C) 2009 Embarcadero Technologies, Inc. All Rights Reserved.
What do you think about this topic? Send feedback!