Mega Code Archive

Ptinrect - tests to see if a point lies within a rectangle types unit

function PtInRect ( const TheRectangle : TRect; const ThePoint : TPoint ) : Boolean; Description The PtInRect function returns true if ThePoint lies within TheRectangle. Note that the rectangle inside is defined as: (left, top, right-1, bottom-1) Related commands Bounds Create a TRect value from top left and size values Point Generates a TPoint value from X and Y values PointsEqual Compares two TPoint values for equality Rect Create a TRect value from 2 points or 4 coordinates TPoint Holds X and Y integer values TRect Holds rectangle coordinate values Example code : Determine inside and outside points of a rectangle var myRect : TRect; begin // Create a rectangle // Note : The rectangle inisde starts at top left, but ends // 1 pixel inside bottom right. myRect := Rect(20, 30, 100, 200); // Check to see if (20,30) is inside the rectangle if PtInRect(myRect, Point(20,30)) then ShowMessage(' 20, 30 is inside the rectangle') else ShowMessage(' 20, 30 is outside the rectangle'); // Check to see if (99,199) is inside the rectangle if PtInRect(myRect, Point(99,199)) then ShowMessage(' 99,199 is inside the rectangle') else ShowMessage(' 99,199 is outside the rectangle'); // Check to see if (100,200) is inside the rectangle if PtInRect(myRect, Point(100,200)) then ShowMessage('100,200 is inside the rectangle') else ShowMessage('100,200 is outside the rectangle'); end; Show full unit code 20, 30 is inside the rectangle 99,199 is inside the rectangle 100,200 is outside the rectangle