. The Program was modfied to use interfaces for Delphi 5 under Windows NT 4.0. To be opportune with the compiler family, the code was adapted to use the free Borland C++ Compiler BCC 5.5. The result is a dynamic liked library with a DELPHI core API. The code is very volatile and it is the start for programming a secure encapsulation of the API as a component. The Program was modfied to use interfaces for Delphi 5 under Windows NT 4.0. To be opportune with the compiler family, the code was adapted to use the free Borland C++ Compiler BCC 5.5. The result is a dynamic liked library with a DELPHI core API. The first Proj library version was 4.4.3. These library version was updated now and synchronized with the code version 4.4.7 coming up from Frank Warmerdam The migration from version 4.4.3 to 4.4.6 and now 4.4.7 has little different resulting behavoir of the proj tools in version 4.4.3 and the library. The Contouring Routine was written by Paul D. Brouke in Fortran and proted by Nicholas Yue into C. For these sources see . CONREC is a contouring subroutine for rectangularily spaced data. It emits calls to a line drawing subroutine supplied by the user which draws a contour map corresponding to double on a randomly spaced rectangular grid. The coordinates emitted are in the same units given in the x and y arrays as sample: and the number of contur levels must be given as sample dimh. As this code is ported as from FORTRAN-77, ANSI C, Delphi and the procedural is of course a PASCALIAN please be very careful of the various indices like remeber that C/C++ and for dynamic arrays in delphi indices starts from zero (0). OK. here is listing with a small example directly applied sample part via a functional definition f(x,y). The basic idea of the algorithm is the desciption of the movement of an unintelligent mouse in a labyrinth with clockwise spin if the move fails and a counter clock wise spin if the move succeeds for the next exploring direction. Versus the contouring other authors like of Paul. D. Brouke it delivers open or closed polygons (rings) and it is possible to create faces over on height intersection plane. To build a DEM or body of heigth lines the algorithm will take more than height intersections and therefore more computational power. In technical terms of the time the routine was implemented as a direct drawing routine to the, in recent considerations, low resoluted PC DOS screen. I extract the these parts from the routine and try to make it industial hard, to check border conditions, uniqe existence polygons of each height inertsected part. Source.