support additional reveal options
diff --git a/R/revealjs_presentation.R b/R/revealjs_presentation.R
index 66fd542..53b3e4f 100644
--- a/R/revealjs_presentation.R
+++ b/R/revealjs_presentation.R
@@ -14,6 +14,8 @@
 #' @param background_transition Slide background-transition ("default", "none", "fade", "slide", 
 #'   "convex", "concave" or "zoom")
 #' @param history \code{TRUE} to push each slide change to the browser history.
+#' @param reveal_options Additional options to specify for reveal.js (see
+#'   \href{https://github.com/hakimel/reveal.js#configuration}{https://github.com/hakimel/reveal.js#configuration} for details). 
 #' @param template Pandoc template to use for rendering. Pass "default"
 #'   to use the rmarkdown package default template; pass \code{NULL}
 #'   to use pandoc's built-in template; pass a path to use a custom template
@@ -86,6 +88,7 @@
                                   transition = "default",
                                   background_transition = "default",
                                   history = TRUE,
+                                  reveal_options = NULL,
                                   highlight = "default",
                                   mathjax = "default",
                                   template = "default",
@@ -146,6 +149,16 @@
   # history
   args <- c(args, pandoc_variable_arg("history", jsbool(history)))
   
+  # additional reveal options
+  if (is.list(reveal_options)) {
+    for (option in names(reveal_options)) {
+      value <- reveal_options[[option]]
+      if (is.logical(value))
+        value <- jsbool(value)
+      args <- c(args, pandoc_variable_arg(option, value))
+    }
+  }
+  
   # content includes
   args <- c(args, includes_to_pandoc_args(includes))
   
diff --git a/man/revealjs_presentation.Rd b/man/revealjs_presentation.Rd
index 7a6e134..4fc1594 100644
--- a/man/revealjs_presentation.Rd
+++ b/man/revealjs_presentation.Rd
@@ -8,9 +8,10 @@
   fig_height = 6, fig_retina = if (!fig_caption) 2, fig_caption = FALSE,
   smart = TRUE, self_contained = TRUE, theme = "simple",
   transition = "default", background_transition = "default",
-  highlight = "default", mathjax = "default", template = "default",
-  css = NULL, includes = NULL, keep_md = FALSE, lib_dir = NULL,
-  pandoc_args = NULL, ...)
+  history = TRUE, reveal_options = NULL, highlight = "default",
+  mathjax = "default", template = "default", css = NULL,
+  includes = NULL, keep_md = FALSE, lib_dir = NULL, pandoc_args = NULL,
+  ...)
 }
 \arguments{
 \item{incremental}{\code{TRUE} to render slide bullets incrementally. Note
@@ -52,6 +53,11 @@
 \item{background_transition}{Slide background-transition ("default", "none", "fade", "slide", 
 "convex", "concave" or "zoom")}
 
+\item{history}{\code{TRUE} to push each slide change to the browser history.}
+
+\item{reveal_options}{Additional options to specify for reveal.js (see
+\href{https://github.com/hakimel/reveal.js#configuration}{https://github.com/hakimel/reveal.js#configuration} for details).}
+
 \item{highlight}{Syntax highlighting style. Supported styles include
 "default", "tango", "pygments", "kate", "monochrome", "espresso",
 "zenburn", and "haddock". Pass \code{NULL} to prevent syntax highlighting.}