LZScene

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//
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// This unit is part of the GLScene Engine https://github.com/glscene
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//
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{
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   Classes and functions that make integration between verlets and glscene
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   objects easy.
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	 History :  
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       23/08/10 - Yar - Added "VectorTypes.pas" unit to uses
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       13/04/04 - MF - Verlet call now uses TVerletProgressTimes
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       06/03/04 - MF - Creation
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}
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unit GLVerletClasses;
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interface
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uses
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  GLVerletTypes, GLVectorGeometry, GLScene, GLObjects, GLVectorTypes;
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type
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  // TGLVerletNode
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  //
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  { Specialized verlet node that can be anchored to a GLScene object. If it's
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     anchored and has the property "NailedDown" set, it will remain in the same
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     relative position to the GLScene object.}
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  TGLVerletNode = class(TVerletNode)
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  private
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    FRelativePosition: TAffineVector;
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    FGLBaseSceneObject: TGLBaseSceneObject;
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    procedure SetGLBaseSceneObject(const Value: TGLBaseSceneObject);
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  protected
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    procedure SetLocation(const Value: TAffineVector);override;
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  public
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    procedure Verlet(const vpt : TVerletProgressTimes); override;
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    property GLBaseSceneObject : TGLBaseSceneObject read FGLBaseSceneObject write SetGLBaseSceneObject;
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    property RelativePosition : TAffineVector read FRelativePosition write FRelativePosition;
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  end;
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  function CreateVCPlaneFromGLPlane(Plane : TGLPlane; VerletWorld : TGLVerletWorld; Offset : single) : TVCFloor;
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//-------------------------------------------------------------------------------------------
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//-------------------------------------------------------------------------------------------
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implementation
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//-------------------------------------------------------------------------------------------
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//-------------------------------------------------------------------------------------------
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function CreateVCPlaneFromGLPlane(Plane : TGLPlane; VerletWorld : TGLVerletWorld; Offset : single) : TVCFloor;
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begin
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  result := TVCFloor.Create(VerletWorld);
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  with result do
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  begin
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    Normal := VectorNormalize(Plane.Direction.AsAffineVector);
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    Location := VectorAdd(Plane.Position.AsAffineVector, VectorScale(Normal, Offset));
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  end;
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end;
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{ TGLVerletNode }
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procedure TGLVerletNode.SetGLBaseSceneObject(
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  const Value: TGLBaseSceneObject);
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begin
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  FGLBaseSceneObject := Value;
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  if Assigned(GLBaseSceneObject) and NailedDown then
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    FRelativePosition := AffineVectorMake(GLBaseSceneObject.AbsoluteToLocal(VectorMake(FLocation, 1)));
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end;
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procedure TGLVerletNode.SetLocation(const Value: TAffineVector);
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begin
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  inherited;
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  if Assigned(GLBaseSceneObject) and NailedDown then
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    FRelativePosition := GLBaseSceneObject.AbsoluteToLocal(Value);
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end;
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procedure TGLVerletNode.Verlet(const vpt : TVerletProgressTimes);
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begin
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  if Assigned(GLBaseSceneObject) and NailedDown then
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  begin
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    FLocation := GLBaseSceneObject.LocalToAbsolute(FRelativePosition);
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  end else
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    inherited;
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end;
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end.
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