% (c) Paul Jungwirth 2006
% You are free to use this file, but please do not modify it.

\NeedsTeXFormat{LaTeX2e}
\ProvidesPackage{bezcirc}[2006/04/14 For drawing circles]

\RequirePackage{ifthen}
\RequirePackage{fp}
\RequirePackage{bez123}

% USAGE: \bezcircle[tblr]{x-center}{y-center}{radius}
% based on http://www.princeton.edu/~graff/files/bezhowto.html
% The optional argument stands for "top,bottom,left,right."
% Use this to get only a quarter or half of a circle.
\DeclareRobustCommand*{\bezcircle}[4][tblr]{
\FPmul{\BCk}{0.5522847498}{#4}
\FPadd{\BCxpr}{#2}{#4}
\FPadd{\BCxpk}{#2}{\BCk}
\FPsub{\BCxmr}{#2}{#4}
\FPsub{\BCxmk}{#2}{\BCk}
\FPadd{\BCypr}{#3}{#4}
\FPadd{\BCypk}{#3}{\BCk}
\FPsub{\BCymr}{#3}{#4}
\FPsub{\BCymk}{#3}{\BCk}
\ifthenelse{\equal{#1}{tblr}}{
\cbezier(\BCxmr,#3)(\BCxmr,\BCypk)(\BCxmk,\BCypr)(#2,\BCypr)
\cbezier(#2,\BCypr)(\BCxpk,\BCypr)(\BCxpr,\BCypk)(\BCxpr,#3)
\cbezier(\BCxpr,#3)(\BCxpr,\BCymk)(\BCxpk,\BCymr)(#2,\BCymr)
\cbezier(#2,\BCymr)(\BCxmk,\BCymr)(\BCxmr,\BCymk)(\BCxmr,#3)
}{
\ifthenelse{\equal{#1}{t}\or\equal{#1}{tl}\or\equal{#1}{l}}{	% NW
\cbezier(\BCxmr,#3)(\BCxmr,\BCypk)(\BCxmk,\BCypr)(#2,\BCypr)
}{}
\ifthenelse{\equal{#1}{t}\or\equal{#1}{tr}\or\equal{#1}{r}}{	% NE
\cbezier(#2,\BCypr)(\BCxpk,\BCypr)(\BCxpr,\BCypk)(\BCxpr,#3)
}{}
\ifthenelse{\equal{#1}{b}\or\equal{#1}{bl}\or\equal{#1}{l}}{	% SW
\cbezier(#2,\BCymr)(\BCxmk,\BCymr)(\BCxmr,\BCymk)(\BCxmr,#3)
}{}
\ifthenelse{\equal{#1}{b}\or\equal{#1}{br}\or\equal{#1}{r}}{	% SE
\cbezier(\BCxpr,#3)(\BCxpr,\BCymk)(\BCxpk,\BCymr)(#2,\BCymr)
}{}
}}