% Generated by roxygen2: do not edit by hand
% Please edit documentation in R/render_alpha_outline.R
\name{offset_alpha}
\alias{offset_alpha}
\title{Offset Alpha Matrix}
\usage{
offset_alpha(alpha, row_offset, col_offset)
}
\arguments{
\item{alpha}{Numeric alpha matrix.}

\item{row_offset}{Integer row offset. Positive values sample from rows below
each output pixel.}

\item{col_offset}{Integer column offset. Positive values sample from columns
to the right of each output pixel.}
}
\value{
Numeric alpha matrix with the same dimensions as \code{alpha}.
}
\description{
Internal shift helper used by \code{fill_alpha_gaps()}. It returns a
same-size alpha matrix shifted by integer row and column offsets, filling
newly exposed pixels with zero instead of wrapping. This lets the gap-filling
scan compare pixels a fixed distance away on opposite sides of a candidate
gap.
}
\keyword{internal}
