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Martin's srpg polygon generator
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cgalab/genpoly-srpg
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The code srpg generates simply-connected and multiply-connected polygons bymeans of a regular grid (with quadratic cells).
Any standard C compiler will do. E.g.:
gcc -O2 -Wall -o srpg srpg.cThis is also basically what the Makefile does, so you could also just runmake.
srgp --Nx <X> --Ny <Y> --output <OUTPUTFILE> [--percent <P>] [--seed <S>] [--holes] [--aligned | --perturb [--smooth <M>]] [--hierarchy <N>] [--diagonal]where X,Y,M,N are positive integers, S is a non-negative integer,0.001 < P < 0.5 is a real, and OUTPUTFILE is the name of the output file.
The computation is based on a grid with X times Y quadratic cells. The userhas to specify X and Y. In addition, the user has to specify the name of anoutput file. If no other options are specified, then srpg generates a polygonwhose edges are parallel to the coordinate axes. The number of vertices of thepolygon generated is random, but it does depend on X, Y and the percentage P:The larger X and Y, the more vertices the polygon tends to have if P is keptconstant. Visually pleasing "random" polygons can be achieved by selectingfairly small values for P, e.g., P:=0.1 or even P:=0.01. (However, a smallvalue of P will also reduce the number of vertices of the polygon.)
The option "--aligned" will cause all vertices to lie on grid points, i.e., tohave integer coordinates. The option "--diagonal" causes srpg to cut off somecorners by line segments with inclination +/-1, thus generating an octagonalpolygon. If the option "--perturb" is used then the vertices are moved awayfrom the grid points and (most) polygon edges will not be parallel to thecoordinate axes. The option "--hierarchy N" instructs srpg to apply N roundsof a recursive refinement to the polygon generated. (Typically, N will be asmall positive integer.) If the option "--holes" is specified then srpg willgenerate a multiply-connected polygonal area. The option "--smooth M" tellssrpg to apply M rounds of corner cutting to the polygon generated, thusgenerating a polygon which resembles a polygonal approximation of a smoothfree-form curve. (Again, M will be a small positive integer.)
Please direct bug reports or suggestions to Martin Held atheld@cs.sbg.ac.at.
This is free software. You may redistribute it and/or modifyit under the terms of the GNU General Public License (v3).