
DIRECTORY Args, Buttons, Commander, Controls, Draw2d, G2dBasic, G2dTool, RealFns, Rope, Vector2, ViewerClasses, ViewerOps;

G2dEllipseCmdImpl: CEDAR PROGRAM
IMPORTS Args, Buttons, Controls, Draw2d, G2dTool, RealFns, Rope, Vector2, ViewerOps
~ BEGIN
Pair:				TYPE ~ G2dBasic.Pair;

EllipseData:		TYPE ~ REF EllipseDataRep;
EllipseDataRep:	TYPE ~ RECORD [
viewer:					ViewerClasses.Viewer м NIL,
graphics:					ViewerClasses.Viewer м NIL,
a, b, scale:				Controls.Control м NIL,
show:						RECORD [ellipse, focci, derivs, accels: BOOL м TRUE],
focus1, focus2:			Pair м [0.0, 0.0],
points:					G2dBasic.PairSequence м NIL,
derivs:					G2dBasic.PairSequence м NIL,
accels:					G2dBasic.PairSequence м NIL
];
G2dEllipse: Commander.CommandProc ~ {
incline, ecc, nPoints: Args.Arg;
[incline, ecc, nPoints] м Args.ArgsGet[cmd, "-incline%r-ecc%r-nPoints%i"
! Args.Error => {msg м reason; CONTINUE}];
IF msg # NIL
THEN RETURN[$Failure, usage]
ELSE {
B: PROC [name: Rope.ROPE] RETURNS [Controls.Button] ~ {
RETURN[Controls.ClickButton[Rope.Concat[name, ": On"], Button, e]];
};
e: EllipseData м NEW[EllipseDataRep];
nPts: INTEGER м IF nPoints.ok THEN nPoints.int ELSE 40;
e.points м NEW[G2dBasic.PairSequenceRep[nPts]];
e.derivs м NEW[G2dBasic.PairSequenceRep[nPts]];
e.accels м NEW[G2dBasic.PairSequenceRep[nPts]];
e.points.length м e.derivs.length м e.accels.length м nPts;
e.a м Controls.NewControl["a", vSlider, e, 0.0, 1.0, 0.5, EllipseControl];
e.b м Controls.NewControl["b", vSlider, e, 0.0, 1.0, 0.25, EllipseControl];
e.scale м Controls.NewControl["scale", vSlider, e, 0.0, 3.0, 1.0, EllipseControl];
ComputeEllipse[e];
e.viewer м Controls.OuterViewer[
name: "G2d Ellipse",
graphicsHeight: 200,
drawProc: DrawEllipse,
controls: LIST[e.a, e.b, e.scale],
buttons: LIST[B["Ellipse"], B["Focci"], B["Derivs"], B["Accels"]],
clientData: e].parent;
e.graphics м NARROW[e.viewer.data, Controls.OuterData].graphics;
};
};

Button: ViewerClasses.ClickProc ~ {
e: EllipseData м NARROW[clientData];
on: BOOL м SELECT TRUE FROM
Rope.Find[parent.name, "Ellipse"] # -1	=> e.show.ellipse	м NOT e.show.ellipse,
Rope.Find[parent.name, "Focci"] # -1	=> e.show.focci	м NOT e.show.focci,
Rope.Find[parent.name, "Derivs"] # -1	=> e.show.derivs	м NOT e.show.derivs,
ENDCASE										=> e.show.accels	м NOT e.show.accels;
Buttons.ReLabel[parent, Rope.Concat[Rope.Substr[parent.name, 0, Rope.Find[parent.name, ":"]+2], IF on THEN "On" ELSE "Off"]];
ViewerOps.PaintViewer[e.graphics, client, FALSE];
};

ComputeEllipse: PROC [e: EllipseData] ~ {
a: REAL м e.a.value*e.scale.value;
b: REAL м e.b.value*e.scale.value;
f: REAL м RealFns.SqRt[ABS[a*a-b*b]];
e.focus1 м IF a > b THEN [f, 0.0] ELSE [0.0, f];
e.focus2 м [-e.focus1.x, -e.focus1.y];
FOR n: NAT IN [0..e.points.length) DO
angle: REAL м REAL[n]*2.0*3.1415926535/REAL[e.points.length];
cos: REAL м RealFns.Cos[angle];
sin: REAL м RealFns.Sin[angle];
e.points[n] м [a*cos, b*sin];
e.derivs[n] м [-a*sin, b*cos];
e.accels[n] м [e.derivs[n].y, -e.derivs[n].x];
ENDLOOP;
};

EllipseControl: Controls.ControlProc ~ {
e: EllipseData м NARROW[control.clientData];
ComputeEllipse[e];
ViewerOps.PaintViewer[e.graphics, client, FALSE];
};

DrawEllipse: Draw2d.DrawProc ~ {
Action: PROC ~ {
TransformPoint: PROC [p: Pair] RETURNS [pp: Pair] ~ INLINE {
pp м [translate.x+scale*p.x, translate.y+scale*p.y];
};
TransformVector: PROC [p: Pair] RETURNS [pp: Pair] ~ INLINE {
pp м [scale*p.x, scale*p.y];
};
scale: REAL м 0.5*MIN[viewer.cw, viewer.ch];
translate: Pair м [0.5*viewer.cw, 0.5*viewer.ch];
e: EllipseData м NARROW[clientData];
p0: Pair м TransformPoint[e.points[e.points.length-1]];
FOR n: NAT IN [0..e.points.length) DO
p1: Pair м TransformPoint[e.points[n]];
deriv: Pair м TransformVector[e.derivs[n]];
IF e.show.ellipse
THEN Draw2d.Line[context, p0, p1];
IF e.show.derivs
THEN Draw2d.Arrow[context, p1, Vector2.Add[p1, TransformVector[e.derivs[n]]]];
IF e.show.accels
THEN Draw2d.Arrow[context, p1, Vector2.Add[p1, TransformVector[e.accels[n]]]];
p0 м p1;
ENDLOOP;
IF e.show.focci THEN {
Draw2d.Mark[context, TransformPoint[e.focus1], asterisk];
Draw2d.Mark[context, TransformPoint[e.focus2], asterisk];
};
};
Draw2d.DoWithBuffer[context, Action];
};
usage: Rope.ROPE м "Test parametric representation of ellipse.";

G2dTool.Register["Ellipse", G2dEllipse, usage];

END.

   в  
G2dEllipseCmdImpl.mesa
Copyright ╙ 1985, 1992 by Xerox Corporation.  All rights reserved.
Bloomenthal, July 20, 1992 1:10 pm PDT
Types
Display
Start Code
 Э╩A  ХNewlineDelimiter
Ц"cedarcode" styleЩ ЩJЪЬ	╧eЬ6ЩBJЩ&JШ JЪ╧k	ЬqШzJШ ЧЪ╤blnЬЮЬЮШ JЪЮЬLШSЧJЪЬЮШheadЪ╧lЩЪЬ	ЮЬШJШ ЧJЪЬЮЬЮЬШ(ЪЬЮЬЮЬШJЪЬ#ЮЬШ'JЪЬ%ЮЬШ)JЪЬ#ЮЬШ'JЪЬЮЬ"ЮЬЮЬШ@JШ$JЪЬ$ЮЬШ(JЪЬ$ЮЬШ(JЪЬ$ЮШ'JШЧЧЪаЩЪ╧b
ЬШ%JШ ШHJЪЬЮЬШ*ЧЪЮЬЮШJЪЮЬЮЬШЪЮЬШЪ╧nЬЮЬЮЬЮЬШ7JЪЮЬ=ШCJШЧJЪЬЮЬШ%JЪ	ЬЮЬЮЬЮЬЮЬШ7JЪЬЮЬ!Ш/JЪЬЮЬ!Ш/JЪЬЮЬ!Ш/JШ;JХStartOfExpansion╗[name: ROPE _ NIL, type: Controls.ControlType _ vSlider, data: REF ANY _ NIL, min: REAL _ 0.0, max: REAL _ 1.0, init: REAL _ 0.5, proc: Controls.ControlProc, report: BOOL _ TRUE, precision: NAT _ 3, row: INTEGER _ 0, x: INTEGER _ 0, y: INTEGER _ 0, w: INTEGER _ 0, h: INTEGER _ 0, textLocation: Controls.TextLocation, dummy: BOOL _ FALSE, detents: LIST OF Controls.Detents _ NIL, taper: Controls.SliderTaper _ lin, values: Controls.RealSequence _ NIL, color: ImagerColor.Color, font: ImagerFont.Font _ NIL, flavor: ATOM _ $Nil]ШJJЦ╗[name: ROPE _ NIL, type: Controls.ControlType _ vSlider, data: REF ANY _ NIL, min: REAL _ 0.0, max: REAL _ 1.0, init: REAL _ 0.5, proc: Controls.ControlProc, report: BOOL _ TRUE, precision: NAT _ 3, row: INTEGER _ 0, x: INTEGER _ 0, y: INTEGER _ 0, w: INTEGER _ 0, h: INTEGER _ 0, textLocation: Controls.TextLocation, dummy: BOOL _ FALSE, detents: LIST OF Controls.Detents _ NIL, taper: Controls.SliderTaper _ lin, values: Controls.RealSequence _ NIL, color: ImagerColor.Color, font: ImagerFont.Font _ NIL, flavor: ATOM _ $Nil]ШKJЦ╗[name: ROPE _ NIL, type: Controls.ControlType _ vSlider, data: REF ANY _ NIL, min: REAL _ 0.0, max: REAL _ 1.0, init: REAL _ 0.5, proc: Controls.ControlProc, report: BOOL _ TRUE, precision: NAT _ 3, row: INTEGER _ 0, x: INTEGER _ 0, y: INTEGER _ 0, w: INTEGER _ 0, h: INTEGER _ 0, textLocation: Controls.TextLocation, dummy: BOOL _ FALSE, detents: LIST OF Controls.Detents _ NIL, taper: Controls.SliderTaper _ lin, values: Controls.RealSequence _ NIL, color: ImagerColor.Color, font: ImagerFont.Font _ NIL, flavor: ATOM _ $Nil]ШRJШШ JШJШJШJЪЬ
ЮЬШ"JЪЬ	ЮЬ5ШBJШЧJЪЬЮЬ-Ш@JШЧЧJШJШ ЧЪвЬШ#JЪЬЮЬШ$ЪЬЮЬЮЬЮЬЮШJЪЬ;ЮЬШNJЪЬ7ЮЬШHJЪЬ9ЮЬШKJЪЮЬЮЬШ6ЧJЦ{[viewer: ViewerClasses.Viewer, hint: ViewerClasses.PaintHint, clearClient: BOOL _ TRUE, whatChanged: REF ANY _ NIL]ЪЬ`ЮЬЮЬЮЬ	Ш}JЪЬ*ЮЬШ1JШJШ ЧЪвЬЮЬШ)JЪЬЮЬШ"JЪЬЮЬШ"JЪЬЮЬЮЬШ%JЪЬЮЬЮЬ
ЮЬ
Ш0JШ&ЪЮЬЮЬЮЬЮШ%JЪЬЮЬЮЬЮЬШ=JЪЬЮЬШJЪЬЮЬШJШJШJШ.JЪЮЬШЧJШJШ ЧЪвЬШ(JЪЬЮЬШ,JШJЦ{[viewer: ViewerClasses.Viewer, hint: ViewerClasses.PaintHint, clearClient: BOOL _ TRUE, whatChanged: REF ANY _ NIL]ЪЬ*ЮЬШ1JШJШ ЧЪвЬШ ЪвЬЮЬШЪвЬЮЬЮЬЮЬШ<JШ4JШЧЪвЬЮЬЮЬЮЬШ=JШJШЧJЪЬЮЬЮЬШ,JШ1JЪЬЮЬШ$JШ7ЪЮЬЮЬЮЬЮШ%JШ'JШ+ЦO[context: Imager.Context, center: VEC, markType: Draw2d.MarkType _ cross]ЪЮЬЮЬШJЪЮЬШ"ЧЪЮЬЮЬШJЪЮЬJШNЧЪЮЬЮЬШJЪЮЬJШNЧJШJЪЮЬШЧЦO[context: Imager.Context, center: VEC, markType: Draw2d.MarkType _ cross]ЪЮЬЮЬЮЬШJШ9JЦO[context: Imager.Context, center: VEC, markType: Draw2d.MarkType _ cross]Ш9JШЧJШЧJШ%JШЧЧЪа
Щ
ЪЬЮЬ0Ш@JШ ЧJШ/JШ ЧЪЮЬШJШ ЧЧ ЕЧ    ╠  п  