[_CD6_]<autolayout>Phoenix23>IPCTGMaker.mesa!2

-- File: IPCTGMaker.mesa

-- Last Edited by: CSChow, February 2, 1985 1:53:21 am PST

--Intro: This purpose of this interface is to construct the Channel Topology Graph

-- (ie. Channel Definition) given as input a collection of components of known positions.

-- It takes as input an instance of IPCoVerifier, which is assumed to have verified that

-- there are no overlappings in the components and output an instance of

-- ChannelsTopologyGraph with the coordinates of the channels assigned.

DIRECTORY

OrderedSymbolTableRef USING[Table],

Misc USING [Interval],

IPParams USING[ChDefaultWidth],

IPCTG USING [Ref, ChType],

IPCoTab USING [Component],

IPCoVerifier USING [Ref];

IPCTGMaker: CEDAR DEFINITIONS

IMPORTS IPParams = BEGIN

-- Intro: The sole reasons for not making most of the fields below opaque is to

-- simply debugging.

Ref: TYPE = REF Rep;

Rep: TYPE = RECORD[comps: CompItems, horPreChs, verPreChs: OrderedSymbolTableRef.Table, xMin, yMin, xMax, yMax: INT];

CompItems: TYPE = REF CompItemsRep;

CompItemsRep: TYPE = RECORD[count: NAT ← 0, compItems: ARRAY CompItemIndices OF CompItem ← ALL [NIL]];

CompItemIndices: TYPE = [1..MaxCompItemCnt];

MaxCompItemCnt: NAT = 100; --%Restriction on maximum number of Components%--

MaxClusterCnt: NAT = 200; --%Restriction on maximum number of Channels%--

CompItem: TYPE = REF CompItemRep;

CompItemRep: TYPE = RECORD[co: IPCoTab.Component, prinPreChs: RECORD [south, east, north, west: PreCh ← NIL], cornerPreChs: RECORD[sw, se, ne, nw: CornerPreChs ← NIL]];

CornerPreChs:TYPE = REF CornerPreChsRep;

CornerPreChsRep: TYPE = RECORD[hor, ver: PreCh];

PreCh: TYPE = REF PreChRep;

PreChRep: TYPE = RECORD[type: IPCTG.ChType, posComp: BOOL, coord: INT, span, range: Misc.Interval, comp: IPCoTab.Component, negBnd, posBnd: PreCh, cluster: NAT ← 0];

Create: PROC[] RETURNS[Ref];

Destroy: PROC [r: Ref];

--This frees up any cyclic pointers and invalidates the instance.

-- Needed because an instance of IPCTGMaker can be reused as often as desired.

ConstructCTG: PROC[r: Ref, cV: IPCoVerifier.Ref, chWidth: NAT ← IPParams.ChDefaultWidth, yPrimary, maxChWidth: BOOL ← TRUE] RETURNS[needGeom: BOOL ← FALSE, ctg: IPCTG.Ref]; --Assumed that the instance of IPCoVerifier has verified that there are no overlaps among

-- the components. If yPrimary is true then the output will tend to have more long vertical

-- running channels else it will give more long horizontal running channels. If maxChWidth

-- is true then the width of the each constructed channel will be set to the maximum possible

-- without moving the components else all channels will be set to chWidth (In any case all

-- channels will be at least chWidth wide.) The output is an instance of Channel Topology

-- Graph with the coordinates of all the channels assigned. If needGeom is true this

-- means that ctg has to be geometrized (ie. the channel position has to be reassigned)

-- otherwise some channels may intersect with the components. This arises mostly

-- because the input configuration of components does not permit the construction

-- of a valid channels structure without moving some components

END.