INTERFACE Appearances;

<* PRAGMA LL *>

IMPORT MG, PaintOp, R2;

TYPE Appearance = MG.Appearance;

TYPE
  DropShadow <: DSPublic;
  DSPublic = Appearance OBJECT
               color: PaintOp.ColorScheme;
               delta: R2.T;
             END;

A DropShadow appearance paints an MG.T twice. First it paints the object offsetting the object's position by delta and its color to color. Then it paints the object with its original position and color.

TYPE
  DropShadowHighlight <: DSHPublic;
  DSHPublic = DropShadow;

A drop shadow appearance where the drop shadow delta is scaled by the object's highlight value. In an animation that changes the highlight value, the effect is to increase the shadow's width and highlight increases.

TYPE
  WeightUnderlay <: WUPublic;
  WUPublic = Appearance OBJECT
               weight: REAL;
               color : PaintOp.ColorScheme;
             END;

A WeightUnderlay appearance paints an MG.T twice. First it paints the object using weight weight and color color. Then it paints the object with its original weight and color.

TYPE
  WeightUnderlayHighlight <: WUHPublic;
  WUHPublic = WeightUnderlay;

A WeightUnderlay appearance where the weight underlay weight is scaled by the object's highlight value. In an animation that changes the highlight value, the effect is to widen the underlay as highlight increases.

TYPE
  Side = {Left, Right, Top, Bottom};
  Sides = SET OF Side;

  Clipped <: ClippedPublic;
  ClippedPublic = MG.AppearanceDefault OBJECT
                    sides: Sides := Sides{Side.Left.. Side.Bottom};
                  END;

A Clipped appearance clips an MG.T proportionally based on the object's highlight value. When highlight = 0, the object is unclipped. When highlight = 1, the object is completely clipped.

The clipping rectangle shrinks in from the sides in self.sides. If two opposing sides are given, the clipping rectangle shrinks to meet in the middle. Otherwise, the clipping rectangle shrinks toward the opposite side.

In an animation that changes the highlight value, the effect is for the shrink as highlight increases.

TYPE
  ColorLineHighlight <: CLHPublic;
  CLHPublic = Appearance OBJECT
                highlightColor: PaintOp.ColorScheme;
                fromFrom                              := TRUE;
              END;

A ColorLineHighlight appearance paints an MG.Line in two colors based on the line's highlight value. In an animation that changes the highlight value, the effect is to change the color of the line starting at one endpoint and moving to the other. If fromFrom is TRUE, then the color change starts at the from endpoint of the line, otherwise it starts at the to endpoint.

It is an error to apply a ColorLineHighlight to an object that isn't a subtype of a MG.Line

END Appearances.