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IfOverlap Rule

Syntax: IfOverlap [Region region_expr] expression [string]

This test fails if any source figure is partially covered by the figures associated with the expression. Unlike the Overlap keyword, this test does not fail if there is no intersection. The expression must be either always true or always false at every point of a source figure, or for every object on the present layer if no Region is given. Figure 15.2 illustrates use of this keyword, for no Region and an expression consisting of a single layer.

Figure 15.2: The IfOverlap test. The present figure (solid) can not be partially covered by figures resulting from evaluating the expression argument (dotted).
\begin{figure}
\vspace{1.5ex}
\begin{center}
\epsfbox{images/ifoverlap.eps}
\end{center}\end{figure}



Stephen R. Whiteley 2021-01-27