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DEFINITION MODULE Regions; (******************************************************************* Module Regions (Version 1.0) Copyright (c) 1993-2006 by Dimitrios Gyalistras and ETH Zurich. Purpose Manage geographical regions (polygons), plus basic operations related to region data. Remarks -- Programming o Design Dimitrios Gyalistras 26/11/1993 o Implementation Dimitrios Gyalistras 26/11/1993 ETH Zurich Systems Ecology CHN E 35.1 Universitaetstrasse 16 8092 Zurich SWITZERLAND URLs: <mailto:RAMSES@env.ethz.ch> <http://www.sysecol.ethz.ch> <http://www.sysecol.ethz.ch/SimSoftware/RAMSES> Last revision of definition: 18/11/1996 DG *******************************************************************) CONST MaxPoints = 8*1024-1; undefinedRegion = MIN(INTEGER); TYPE RealVecPtr = POINTER TO RealVec; RealVec = ARRAY [1..MaxPoints] OF REAL; RegionChange = (regionDefined, regionReplaced, regionRemoved); AtRegionChangeP = PROCEDURE( RegionChange, (* signifies type of change *) INTEGER ); (* number of the region affected *) AtReadDataPointP = PROCEDURE( VAR REAL, (* x-Coordinate *) VAR REAL, (* y-Coordinate *) VAR ARRAY OF CHAR (* error text to pass on *) ): BOOLEAN; (* if false, reading stops *) CalcDistanceP = PROCEDURE( REAL, REAL, (* x1/y1 *) REAL, REAL (* x2/y2 *) ): REAL; (* the distance *) (*--------------------------------------------------------------------------*) (* Calculation of distances *) (*--------------------------------------------------------------------------*) PROCEDURE SetCalcDistanceP( calcDistP: CalcDistanceP ); PROCEDURE GetCalcDistanceP( VAR calcDistP: CalcDistanceP ); (*--------------------------------------------------------------------------*) (* Definition and removal of regions *) (*--------------------------------------------------------------------------*) PROCEDURE DefineRegionsFromFile( fileName : ARRAY OF CHAR; atReadDataPoint : AtReadDataPointP; progrReprt : PROC; replaceExisting : BOOLEAN; VAR nDefined :INTEGER ; VAR errTxt : ARRAY OF CHAR ); (* Reads region data from the file "fileName" and returns in "nDefined" the number of regions actually (re)defined based on the contents of this file. If "nRead=-1", an error occurred which is explained in "errTxt". If "replaceExisting=TRUE" and in the file was found a region with the number of an already defined region, the latter will be redefined, i.e. replaced by the newly read region. Otherwise the region read from the file is neglected. Procedure "progrReprt" is called each time a region has been scanned from the file. *) PROCEDURE SimplifyRegionBoundaries( inFileName : ARRAY OF CHAR; outFileName : ARRAY OF CHAR; atReadDataPoint : AtReadDataPointP; progrReprt : PROC; minDist : REAL; idOffset : INTEGER; VAR nSimplified :INTEGER ; VAR errTxt : ARRAY OF CHAR ); (* Reads region data from the file "inFileName", simplifies the boundaries of all regions by replacing - wherever possible - all points less than "minDist" apart by a single point, and writes the result to file "outFileName". "nSimplified" returns the number of regions processed. NOTE: This procedure is particularly usefull, if a region is defined by more than "MaxPoints" and can thus not be read from file using procedure "DefineRegionsFromFile". *) PROCEDURE DefineRegion( rNr : INTEGER; name : ARRAY OF CHAR; cntrX, cntrY : REAL; nPoints : INTEGER; xC, yC : ARRAY OF REAL; VAR errTxt : ARRAY OF CHAR ): BOOLEAN; (* Defines a region. If a region with number "rNr" already exists, it is redefined. In case of an error the procedure returns FALSE and an explanation in "errTxt"; if a region "rNr" already already existed, it is left untouched. *) PROCEDURE RemoveRegion( rNr: INTEGER ); PROCEDURE RemoveAllRegions; PROCEDURE InstallAtRegionsChangedHandler( rch: AtRegionChangeP ); (* This procedure allows to install a handler "rch" which is called each time a change in the regions occurs. *) (*--------------------------------------------------------------------------*) (* Retrieval of regions and their attributes *) (*--------------------------------------------------------------------------*) PROCEDURE NRegions():INTEGER; PROCEDURE RegionExists( rNr:INTEGER ): BOOLEAN; PROCEDURE GetRegionNumbers( VAR rNum : ARRAY OF INTEGER; VAR nRegions: INTEGER); PROCEDURE GetRegionAttrs( rNr: INTEGER; VAR name: ARRAY OF CHAR; VAR left: BOOLEAN; VAR cntrX, cntrY, minX, minY, maxX, maxY, meanDist: REAL): BOOLEAN; (* Returns attributes of region "rNr". Returns FALSE if the region was not found. *) PROCEDURE GetRegionCoords( rNr: INTEGER; VAR nElems: INTEGER; VAR xC, yC: RealVecPtr): BOOLEAN; (* Returns number of elements and pointers to coordinate vectors of region "rNr". Returns FALSE if the region was not found. *) (*--------------------------------------------------------------------------*) (* Geographical relationships *) (*--------------------------------------------------------------------------*) PROCEDURE InRegion( rNr: INTEGER; xC, yC: REAL ): BOOLEAN; (* Returns TRUE if point with coordinates "xC,yC" is within region "rNr". *) PROCEDURE RegionOfPoint( xC, yC: REAL ): INTEGER; (* Returns the number of the first found region which contains the point with coordinates "xC,yC". Returns undefinedRegion, if no region is found. *) PROCEDURE ClosestBoundary( rNr: INTEGER; xC, yC: REAL; VAR xB, yB, dist: REAL); (* Returns in "xS,yS" the coordinates of the closest point to "xC,yC" on the boundary of region "rNr". "dist" is the corresponding distance. It is >0, if the point is outside the region, otherwise <0. *) END Regions.
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