File pgf/libraries/pgflibraryfixedpointarithmetic.code.tex (tested with TikZ 3.0) contains unwanted white spaces at line ends that leak into the drawing and moves the following elements to the right, if functions like atan2/abs/...
are used. Example:
\documentclass[tikz, convert = false]{standalone}%
\usepackage{fp}
\usetikzlibrary{fixedpointarithmetic}
\usetikzlibrary{calc}
\begin{document}
\begin{tikzpicture}
\fill[blue] (0,0) circle[radius=1pt];
\fill(1,0) circle[radius=.5pt];
\path[fixed point arithmetic] let
\n1 = {atan2(57pt, 85pt)}
in;
\fill[red] (0,0) circle[radius=.5pt];
\end{tikzpicture}
\end{document}
The red circle should be on top of the blue circle (both in the origin), but it is moved to the right.
The problem was found by dustin at tex.stackexchange.com: fixed point arithmetic is all wacky now.
I found three places with unwanted line ends (atan2 uses abs):
--- pgflibraryfixedpointarithmetic.code.tex.org 2014-02-27
--- 01:01:50.000000000 +0100
+++ pgflibraryfixedpointarithmetic.code.tex 2014-04-27
14:58:13.308190620 +0200
@@ -273,7 +273,7 @@
}
\def\pgfmathfpabs@#1{%
\begingroup%
- \FPabs\pgfmathresult{#1}
+ \FPabs\pgfmathresult{#1}%
\pgfmath@smuggleone\pgfmathresult%
\endgroup%
}
@@ -561,7 +561,7 @@
\begingroup%
\FPmul\pgfmathresult{#1}{0.017453292519943295}%
\FPcos\pgfmathresult{\pgfmathresult}%
- \FPdiv\pgfmathresult{1}{\pgfmathresult}
+ \FPdiv\pgfmathresult{1}{\pgfmathresult}%
\pgfmath@smuggleone\pgfmathresult%
\endgroup%
}
@@ -576,7 +576,7 @@
\begingroup%
\FPmul\pgfmathresult{#1}{0.017453292519943295}%
\FPsin\pgfmathresult{\pgfmathresult}%
- \FPdiv\pgfmathresult{1}{\pgfmathresult}
+ \FPdiv\pgfmathresult{1}{\pgfmathresult}%
\pgfmath@smuggleone\pgfmathresult%
\endgroup%
}
