add doc

DESCRIPTION

@@ -11,3 +11,7 @@ LazyData: true
 LinkingTo: Rcpp
 Imports: Rcpp, imager, stats
 RoxygenNote: 7.1.0
+Suggests: 
+    knitr,
+    rmarkdown
+VignetteBuilder: knitr

R/io.r

@@ -15,15 +15,16 @@ getdepthmap <- function(path, cutoff = 0.5){
 
 #' read in image and change them into magic eye
 #' @param img cimg object
+#' @param len length of pattern square,default 50.
 #' @param shift shift of magic eye, default 0.15
 #' @return NULL
 #' @export
 
-getme <- function(img,shift=0.15){
+getme <- function(img,len = 50, shift=0.15){
         d <- dim(img)
         mask <- matrix(as.numeric(img),d[1],d[2])
         i <- imager::as.cimg(mask,dim=c(d[1],d[2],d[3],1))
-        c1 <- matrix(stats::runif(50*50,0,1),50,50)
+        c1 <- matrix(stats::runif(len*len,0,1),len,len)
         o <- getmagiceye(t(mask), c1, shift)
         o <- t(o)
         o <- imager::as.cimg(o,dim=c(d[1],d[2],d[3],1))
@@ -32,11 +33,12 @@ getme <- function(img,shift=0.15){
 
 #' read in text
 #' @param text text
+#' @param cex default 20
 #' @return NULL
 #' @export
 
-getmet <- function(text = 'yufree'){
+getmet <- function(text = 'yufree',cex = 20){
         bg <- imager::imfill(1000,1000,val=1)
-        o <- imager::implot(bg,text(500,500,text,cex=20))
+        o <- imager::implot(bg,text(500,500,text,cex=cex))
         return(1-o)
 }

vignettes/.gitignore

@@ -0,0 +1,2 @@
+*.html
+*.R

vignettes/MagicEye.Rmd

@@ -0,0 +1,54 @@
+---
+title: "Magic Eye in R"
+output: rmarkdown::html_vignette
+vignette: >
+  %\VignetteIndexEntry{Magic Eye in R}
+  %\VignetteEngine{knitr::rmarkdown}
+  %\VignetteEncoding{UTF-8}
+---
+
+```{r, include = FALSE}
+knitr::opts_chunk$set(
+  collapse = TRUE,
+  comment = "#>"
+)
+```
+
+```{r setup}
+library(magiceyer)
+```
+
+You could use this package to generate autostereograms.
+
+## How
+
+- You need an image as the shape hidden in the magic eye
+
+- Convert the image into the depthmap 
+
+- You need to define shift. 0.1-0.2 should be fine.
+
+- Generate the autostereograms
+
+```{r demo}
+image <- getdepthmap("https://cran.r-project.org/Rlogo.jpg")
+plot(image)
+me <- getme(image,len = 10)
+plot(me)
+```
+
+You could also generate text as hidden information in the autostereograms
+
+```{r text}
+met <- getmet(text = "Don't Panic",cex = 15)
+me <- getme(met)
+plot(me)
+```
+
+## Why
+
+- [Wiki](https://en.wikipedia.org/wiki/Magic_Eye)
+
+- [History](https://eyeondesign.aiga.org/the-hidden-history-of-magic-eye-the-optical-illusion-that-briefly-took-over-the-world/)
+
+- [Python](https://flothesof.github.io/making-stereograms-Python.html)