DIRECTORYCD USING [Rect, Design],CDBasics,CDDrawQueue;CDDrawQueueImpl: CEDAR MONITOR IMPORTS CDBasicsEXPORTS CDDrawQueueSHARES CD = BEGINDrawQueue: TYPE = REF DrawQueueRep;Request: TYPE = CDDrawQueue.Request;QueueList: TYPE = LIST OF DrawQueue;maxC: CARD16 = 50;DrawQueueRep: PUBLIC TYPE = RECORD [fancyList: LIST OF Request _ NIL,fancyLast: LIST OF Request _ NIL,cnt, in, out: CARD16,commandAvail: CONDITION,desgn: CD.Design,deviceClip: CD.Rect,comm: ARRAY [0..maxC) OF Request,stopFlag: REF BOOL, -- must be monitoredactive: BOOL _ FALSE,deleted: BOOL _ FALSE,alldoneToBeReported: BOOL _ FALSE,inProgress: Request _ [NIL, CDBasics.universe]];queueEmpty: PUBLIC REF _ NEW[INT];finishedForEver: PUBLIC REF _ NEW[INT];Activate: INTERNAL PROC [dq: DrawQueue] = {IF NOT dq.active THEN {list: QueueList _ NARROW[dq.desgn.cdDrawQueuePriv];list _ CONS[dq, list];dq.desgn.cdDrawQueuePriv _ list;dq.active _ TRUE;};};DeActivate: INTERNAL PROC [dq: DrawQueue] = {IF dq.active THEN {list: QueueList _ NARROW[dq.desgn.cdDrawQueuePriv];IF list=NIL THEN RETURN; -- list#NIL; otherwise nothing too delete! not dq.active; but don't be pickyIF list.first=dq THEN dq.desgn.cdDrawQueuePriv _ list.restELSEFOR l: QueueList _ list, l.rest WHILE l.rest#NIL DOIF l.rest.first=dq THEN {l.rest _ l.rest.rest; EXIT}ENDLOOP;dq.active _ FALSE;};};Create: PUBLIC ENTRY PROC [design: CD.Design, stopFlag: REF BOOL, clip: CD.Rect_[1,1,0,0]] RETURNS [DrawQueue] = {ENABLE UNWIND => NULL; --catches eg on stopFlag=NILdq: DrawQueue = NEW[DrawQueueRep];IF stopFlag=NIL THEN stopFlag _ NEW[BOOL_FALSE];dq.cnt _ dq.in _ dq.out _ 0;dq.deviceClip _ CDBasics.empty;dq.desgn _ design;dq.stopFlag _ stopFlag;  -- assigns addressesdq.deleted _ dq.active _ dq.alldoneToBeReported _ dq.stopFlag^ _ FALSE;InternalChangeClipArea[dq, clip];RETURN [dq]};ChangeClipArea: PUBLIC ENTRY PROC [dq: DrawQueue, clip: CD.Rect] = {ENABLE UNWIND => NULL; InternalChangeClipArea[dq, clip];};InternalChangeClipArea: INTERNAL PROC [dq: DrawQueue, clip: CD.Rect] = {InternalFlushAll[dq];dq.deviceClip _ clip;IF CDBasics.NonEmpty[clip] THEN Activate[dq] ELSE DeActivate[dq]};Destroy: PUBLIC ENTRY PROC [dq: DrawQueue] = {ENABLE UNWIND => NULL; IF dq#NIL THEN {dq.deleted _ TRUE; InternalFlushAll[dq];DeActivate[dq]; dq.desgn _ NIL;}};QueueInsertDrawCommand: PUBLIC ENTRY PROC [dq: DrawQueue, req: Request] = {ENABLE UNWIND => NULL; IF dq#NIL AND dq.active THEN InternalInsertCommand[dq, req]};InsertFancy: INTERNAL PROC [dq: DrawQueue, req: Request] = INLINE {IF dq.fancyList=NIL THEN dq.fancyList _ dq.fancyLast _ LIST[req]ELSE {dq.fancyLast.rest _ LIST[req];dq.fancyLast _ dq.fancyLast.rest;};NOTIFY dq.commandAvail;};Stronger: PROC [a, b: REF] RETURNS [ATOM] = INLINE {RETURN [IF a=$redraw OR b=$redraw THEN $redraw ELSE $draw];};InternalInsertCommand: INTERNAL PROC [dq: DrawQueue, req: Request] = {dq.alldoneToBeReported _ TRUE;IF req.key#$redraw AND req.key#$draw THEN InsertFancy[dq, req]ELSE { j: CARD16;IF ~CDBasics.Intersect[req.rect, dq.deviceClip] THEN RETURN;req.rect _ CDBasics.Intersection[req.rect, dq.deviceClip];IF dq.cnt>=maxC THEN { InternalFlushDraw[dq];InsertFancy[dq, Request[$flushed, dq.deviceClip]];req _ Request[$redraw, dq.deviceClip];};IF CDBasics.Inside[dq.inProgress.rect, req.rect] THEN {IF dq.inProgress.key=$redraw OR dq.inProgress.key=$draw THEN {dq.stopFlag^ _ TRUE;req.key _ Stronger[req.key, dq.inProgress.key];};};j  _ dq.out;THROUGH [0..dq.cnt) DOIF CDBasics.Intersect[req.rect, dq.comm[j].rect] THEN {IF CDBasics.Inside[req.rect, dq.comm[j].rect] THEN {dq.comm[j].key _ Stronger[dq.comm[j].key, req.key];RETURN};IF CDBasics.Inside[dq.comm[j].rect, req.rect] THEN {dq.comm[j].key _ Stronger[dq.comm[j].key, req.key];dq.comm[j].rect _ req.rect; RETURN};};j _ (j+1) MOD maxC;ENDLOOP;dq.cnt _ dq.cnt+1;dq.comm[dq.in] _ req;dq.in _ (dq.in+1) MOD maxC;NOTIFY dq.commandAvail;};};InsertDrawCommand: PUBLIC ENTRY PROC [design: CD.Design, req: Request] = {ENABLE UNWIND => NULL; FOR lst: QueueList _ NARROW[design.cdDrawQueuePriv], lst.rest WHILE lst#NIL DOInternalInsertCommand[lst.first, req];ENDLOOP};lastFirst: BOOL _ TRUE;FetchCommand: PUBLIC ENTRY PROC [dq: DrawQueue] RETURNS [req: Request] = {ENABLE UNWIND => NULL; dq.stopFlag^ _ FALSE;WHILE dq.cnt<=0 AND dq.fancyList=NIL DO IF dq.deleted THEN InsertDisappear[dq]ELSE IF dq.alldoneToBeReported THEN {InsertFancy[dq, Request[queueEmpty, [1,1,0,0]]];dq.alldoneToBeReported _ FALSE;}ELSE WAIT dq.commandAvail;dq.stopFlag^ _ FALSE;ENDLOOP;IF dq.fancyList#NIL THEN {dq.inProgress _ req _ dq.fancyList.first;dq.fancyList _ dq.fancyList.rest;RETURN};dq.cnt _ dq.cnt-1;IF dq.cnt>2 THEN {dq.in _ (dq.in+maxC-1) MOD maxC;dq.inProgress _ req _ dq.comm[dq.in];}ELSE {dq.inProgress _ req _ dq.comm[dq.out];dq.out _ (dq.out+1) MOD maxC;};};Flush: PUBLIC ENTRY PROC [dq: DrawQueue] = {ENABLE UNWIND => NULL; IF dq#NIL THEN InternalFlushAll[dq]};InternalFlushAll: INTERNAL PROC [dq: DrawQueue] = {dq.fancyList _ dq.fancyLast _ NIL;InternalFlushDraw[dq];};InternalFlushDraw: INTERNAL PROC [dq: DrawQueue] = {dq.cnt _ dq.in _ dq.out _ 0;dq.stopFlag^ _ TRUE;dq.alldoneToBeReported _ FALSE;dq.inProgress _ [NIL, CDBasics.universe];NOTIFY dq.commandAvail;};InsertDisappear: INTERNAL PROC [dq: DrawQueue] = {dq.fancyList _ dq.fancyLast _ LIST[Request[finishedForEver, [1,1,0,0]]];};END.  h  CDDrawQueueImpl.mesa     (part of ChipNDale)Copyright c 1983, 1986, 1987 by Xerox Corporation.  All rights reserved.Created by Christian Jacobi   July 6, 1983 5:09 pm Last edited by: Christian April 17, 1987 3:44:03 pm PDT-- request to stop the execution of (only!) the current command--stopFlag^ tells any drawing process to stop volunterly and to fetch the next command. --stopFlag^ must not be modified any more outside this monitor!!--until DeleteCommandTable is called--Users may request a stop by calling Flush.--changes the clipping aera--changes the clipping aera--no more insertion calls on dq allowed!!--redraw process must disapear from itself,--when redraw process dispears and contains nomore--reference of dq, it is subject for garbage collection --The stopFlag is immediately set to TRUE and later--reset to FALSE when the redraw --process stopped the current command, if it then fetches another --command it gets the disapearforever command.--regular draw requests--table overflow check--should painting stop?--try matching--enqueue--waits till command is available or DrawQueue deleted--silly heuristic; --if 2 elements it looks more like movement to clear the old area first--but if there is a backlog we want to draw the newest things first-- the drawing may stop after some time only,-- and NOT immediately with procedure returnЭ╩	├  Ш codeЪЬ,Щ,KЪЬ
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