DIRECTORY CD, CDBasics, OnionArc, PWPins, Rope; OnionArcImpl: CEDAR PROGRAM IMPORTS CDBasics EXPORTS OnionArc = BEGIN OPEN OnionArc; PointInSeg: PROC [point: INT, thisSide: Side, seg: Seg, rect: CD.Rect] RETURNS [in: BOOL _ FALSE] = { IsInThisBit: EachSegBitProc = {in _ in OR (side=thisSide AND min<=point AND point<=max)}; SegEnumerateSegBits[seg, rect, IsInThisBit]; }; SegLength: PROC [seg: Seg, rect: CD.Rect] RETURNS [length: INT _0] = { LengthSegBit: EachSegBitProc = {IF min>max THEN ERROR; length _ length + max - min}; SegEnumerateSegBits[seg, rect, LengthSegBit]; }; SegIntersect: PROC [seg1, seg2: Seg, rect: CD.Rect] RETURNS [intersect: BOOL] = { intersect _ PointInSeg[seg1.point1, seg1.side1, seg2, rect] OR PointInSeg[seg2.point1, seg2.side1, seg1, rect]; }; SegExtent: PROC [seg: Seg, rect: CD.Rect, dist: INT] RETURNS [newSeg: Seg] = { newPoint2: INT _ seg.point2; newSide2: Side _ seg.side2; SELECT seg.side2 FROM bottom => IF newPoint2+dist<=rect.x2 THEN newPoint2 _ newPoint2+dist ELSE {newPoint2 _ rect.y1+dist; newSide2 _ right}; right => IF newPoint2+dist<=rect.y2 THEN newPoint2 _ newPoint2+dist ELSE {newPoint2 _ rect.x2-dist; newSide2 _ top}; top => IF newPoint2-dist>=rect.x1 THEN newPoint2 _ newPoint2-dist ELSE {newPoint2 _ rect.y2-dist; newSide2 _ left}; left => IF newPoint2-dist>=rect.y1 THEN newPoint2 _ newPoint2-dist ELSE {newPoint2 _ rect.x1+dist; newSide2 _ bottom}; ENDCASE => ERROR; newSeg _ NEW[SegRec _ [point1: seg.point1, side1: seg.side1, point2: newPoint2, side2: newSide2]]; }; SegEnumerateSegBits: PROC [seg: Seg, rect: CD.Rect, eachSegBit: EachSegBitProc] = { point: INT _ seg.point1; side: Side _ seg.side1; WHILE side#seg.side2 OR (SELECT side FROM bottom, right => seg.point2 seg.point2>point, ENDCASE => ERROR) DO SELECT side FROM bottom => {eachSegBit[point, rect.x2, bottom]; point _ rect.y1; side _ right}; right => {eachSegBit[point, rect.y2, right]; point _ rect.x2; side _ top}; top => {eachSegBit[rect.x1, point, top]; point _ rect.y2; side _ left}; left => {eachSegBit[rect.y1, point, left]; point _ rect.x1; side _ bottom}; ENDCASE => ERROR; ENDLOOP; eachSegBit[MIN[point, seg.point2], MAX[point, seg.point2], side]; }; EmptyArc: PUBLIC PROC [rect: CD.Rect] RETURNS [arc: Arc] = { arc _ NEW [ArcRec _ [rect: rect, segs: NIL]]; }; Length: PUBLIC PROC [arc: Arc] RETURNS [length: INT _ 0] = { FOR segs: LIST OF Seg _ arc.segs, segs.rest WHILE segs#NIL DO length _ length + SegLength[segs.first, arc.rect]; ENDLOOP; }; Positive: PROC [side: Side] RETURNS [positive: BOOL] = { positive _ SELECT side FROM bottom, right => TRUE, left, top => FALSE, ENDCASE => ERROR; }; ConnectSegBitToArc: PUBLIC PROC [min, max: INT, side: Side, arc: Arc] RETURNS [connection: Arc] = { rect: CD.Rect _ arc.rect; segs: LIST OF Seg _ NIL; seg: Seg; SELECT side FROM bottom, top => {rect.x1 _ MIN[rect.x1, min]; rect.x2 _ MAX[rect.x2, max]}; right, left => {rect.y1 _ MIN[rect.y1, min]; rect.y2 _ MAX[rect.y2, max]}; ENDCASE => ERROR; IF ~Positive[side] THEN {w: INT _ min; min _ max; max _ w}; IF arc.segs=NIL THEN seg _ NEW [SegRec _ [point1: min, point2: max, side1: side, side2: side]] ELSE { IF arc.segs.rest#NIL THEN ERROR; seg _ arc.segs.first; SELECT TRUE FROM PointInSeg[min, side, seg, rect] AND PointInSeg[max, side, seg, rect] => {}; PointInSeg[min, side, seg, rect] => seg _ NEW[SegRec _ [point1: seg.point1, side1: seg.side1, point2: max, side2: side]]; PointInSeg[max, side, seg, rect] => seg _ NEW[SegRec _ [point1: min, side1: side, point2: seg.point2, side2: seg.side2]]; ENDCASE => { possibleSeg1: Seg _ NEW[SegRec _ [point1: seg.point1, point2: max, side1: seg.side1, side2: side]]; possibleSeg2: Seg _ NEW[SegRec _ [point1: min, point2: seg.point2, side1: side, side2: seg.side2]]; seg _ IF SegLength[possibleSeg1, rect] < SegLength[possibleSeg2, rect] THEN possibleSeg1 ELSE possibleSeg2; }; }; connection _ NEW [ArcRec _ [rect: rect, segs: LIST [seg]]]; RETURN; }; NotOverlinsting: PUBLIC PROC [arc1, arc2: Arc, minDist: INT] RETURNS [notOverlinsting: BOOL _ TRUE] = { rect: CD.Rect _ CDBasics.Surround[arc1.rect, arc2.rect]; FOR segs1: LIST OF Seg _ arc1.segs, segs1.rest WHILE segs1#NIL DO extSeg1: Seg _ SegExtent[segs1.first, rect, minDist]; FOR segs2: LIST OF Seg _ arc2.segs, segs2.rest WHILE segs2#NIL DO IF SegIntersect[extSeg1, SegExtent[segs2.first, rect, minDist], rect] THEN { RETURN[FALSE]; }; ENDLOOP; ENDLOOP; }; Union: PUBLIC PROC [arc1, arc2: Arc] RETURNS [union: Arc] = { rect: CD.Rect _ CDBasics.Surround[arc1.rect, arc2.rect]; segs: LIST OF Seg _ arc2.segs; FOR segs1: LIST OF Seg _ arc1.segs, segs1.rest WHILE segs1#NIL DO segs _ CONS[segs1.first, segs]; ENDLOOP; union _ NEW[ArcRec _ [rect: rect, segs: segs]]; }; EnumerateSegBits: PUBLIC PROC [arc: Arc, eachSegBit: EachSegBitProc] = { FOR segs: LIST OF Seg _ arc.segs, segs.rest WHILE segs#NIL DO SegEnumerateSegBits[segs.first, arc.rect, eachSegBit]; ENDLOOP; }; END. :OnionArcImpl.mesa Copyright c 1985 by Xerox Corporation. All rights reversed. Created by Bertrand Serlet, August 19, 1985 5:15:59 pm PDT Last Edited by: Serlet, July 3, 1985 2:05:09 pm PDT -- The projection of the point according to side is assumed to intersect the "ring" defined by the segment Extends the segment after point2 Extend rect according to point Test whether segs is empty Estimates for each seg the price of extending the seg to point in both directions The 2 arcs can be of different sizes The union is positionned to fit on the largest rect. Êd˜– "Cedar" stylešœ™Jšœ Ïmœ1™