Interface of SDL_SLine

const
{$IFDEF PAIDVERS}
  SDLVersionInfo = 'sline_r1200_full';
  IsLightEd = false;
{$ELSE}
  SDLVersionInfo = 'sline_r1200_lighted';
  IsLightEd = true;
{$ENDIF}
  Release = 1200;

type
  ESDLSLineError = class(Exception);       { exception type to indicate errors }
  TSLine = class (TComponent)
                 private
                   FParA    : double;
                   FParB    : double;
                   FParC    : double;
                   FSubstInf: boolean;
                   procedure SetParA (value: double);
                   procedure SetParB (value: double);
                   procedure SetParC (value: double);
                   function GetDirect: double;
                   function GetSlope: double;
                   function GetIntercept: double;
                 protected
                 public
                   constructor Create (AOwner: TComponent); override;
                   destructor  Destroy; override;
                   function AngleBetweenLines (OtherLine: TSLine): double;
                   procedure CalcKDForm (var k, d: double);
                   function CalcX (y: double): double;
                   function CalcY (x: double): double;
                   function ClipBox (bllx, blly, burx, bury: double;
                                   var x1, y1, x2, y2: double): boolean;
                   property Direction: double read GetDirect;
                   property Slope: double read GetSlope;
                   property Intercept: double read GetIntercept;
                   function Distance (px, py: double): double;
                   function InterSection (OtherLine: TSLine;
                               var x,y: double): boolean;
                   function LineFrom2Points (P1X, P1Y, P2X, P2Y: double): boolean;
                   procedure LineThroughPoint (px, py, angle: double);
                   procedure LineFromSlopeIcpt (k, d: double);
                   procedure NormalLine (px, py: double; OtherLine: TSLine);
                   procedure ParallelLine (px, py: double; OtherLine: TSLine);
                 published
                   property SubstituteInf: boolean read FSubstInf write FSubstInf;
                   property ParA: double read FParA write SetParA;
                   property ParB: double read FParB write SetParB;
                   property ParC: double read FParC write SetParC;
               end;