<<>>
<<G2dImplicitCmdsImpl.mesa>>
<<Copyright Ó 1985, 1992 by Xerox Corporation.  All rights reserved.>>
<<Bloomenthal, August 25, 1992 2:21 pm PDT>>

DIRECTORY Commander, Controls, Draw2d, G2dBasic, G2dImplicitTool, G2dTool, G2dVector, Rope;

G2dImplicitCmdsImpl: CEDAR PROGRAM
IMPORTS Controls, Draw2d, G2dImplicitTool, G2dTool, G2dVector

~ BEGIN
<<Types>>
CommandProc:        TYPE ~ Commander.CommandProc;
Tool:                    TYPE ~ G2dImplicitTool.Tool;
Pair:                    TYPE ~ G2dBasic.Pair;
ROPE:                    TYPE ~ Rope.ROPE;
<<Simple Surfaces>>
SimpleType:            TYPE ~ {circle, blob};

SimpleData:            TYPE ~ REF SimpleDataRep;
SimpleDataRep:        TYPE ~ RECORD [
tool:                            Tool ¬ NIL,
radius:                        Controls.Control ¬ NIL,
radiusSquared:                REAL ¬ 1.0,
blobSep:                        REAL ¬ 0.25,
type:                            SimpleType ¬ circle
];

SimpleCommand: CommandProc ~ {
s: SimpleData ~ NEW[SimpleDataRep];
s.tool ¬ G2dImplicitTool.MakeTool[
name: "Simple",
valueProc: Value,
clientDraw: Draw, 
clientData: s,
extraControls: LIST[s.radius ¬ Controls.NewControl["Radius",, s, 0, 5, 1, Radius]],
extraButtons: LIST[
Controls.ClickButton["Circle", TypeCycle, s],
Controls.ClickButton["Blob Sep", BlobSep, s]]
];
};

Value: G2dImplicitTool.ValueProc ~ {
s: SimpleData ¬ NARROW[clientData];
SELECT s.type FROM
circle => value ¬ point.x*point.x+point.y*point.y-s.radiusSquared;
blob => {
centers: ARRAY [0..1] OF Pair ¬ [[-s.blobSep, 0.0], [s.blobSep, 0.0]];
FOR n: NAT IN [0..1] DO
value ¬ value+1.0/MAX[.001, G2dVector.SquareDistance[centers[n], point]];
ENDLOOP;
};
ENDCASE;
};

Radius: Controls.ControlProc ~ {
s: SimpleData ¬ NARROW[clientData];
s.radiusSquared ¬ s.radius.value*s.radius.value;
G2dImplicitTool.Repaint[s.tool, $Client];
};

Draw: Draw2d.DrawProc ~ {
s: SimpleData ¬ NARROW[clientData];
SELECT s.type FROM
circle => Draw2d.Circle[context, [0, 0], s.radius.value];
ENDCASE;
};

BlobSep: Controls.ClickProc ~ {
d: SimpleData ~ NARROW[clientData];
d.blobSep ¬ Controls.GetReal[d.tool.typescript, "Blob Separation", d.blobSep];
};

TypeCycle: Controls.ClickProc ~ {
Roper: PROC [type: SimpleType] RETURNS [ROPE] ~ {
RETURN[SELECT type FROM
circle    => "Circle",
blob    => "Blob",
ENDCASE    => NIL];
};
d: SimpleData ~ NARROW[clientData];
old: SimpleType ~ d.type;
d.type ¬ IF old = SimpleType.LAST THEN SimpleType.FIRST ELSE SUCC[old];
Controls.ButtonRelabel[d.tool.outerData, Roper[old], Roper[d.type]];
IF mouseButton = blue THEN G2dImplicitTool.Repaint[d.tool, $Client];
};
<<Start Code>>
G2dTool.Register["ImplicitFunction", SimpleCommand, "ImplicitFunction <option | ?>"];
G2dImplicitTool.Register["Simple", SimpleCommand, "stuff."];

END.