Create sync leaflet maps from a Geotiff, see https://www.giorgiocomai.eu/testzone/sibiu1934/

sibiu_1934_map.Rmd

---
title: "Sibiu 1934 historic map"
output: html_document
---

```{r setup, include=FALSE}
knitr::opts_chunk$set(echo = TRUE)
library("tidyverse")
library("leaflet")
library("leaflet.opacity")
library("tiler")
library("leafsync")
```

## Create the tiles from a Geotiff

```{r}
# fs::dir_create("tiles")
# tiler::tile(file = "sibiu_map_modified_mercator.tif",
#             tiles = "tiles",
#             zoom = "11-18")
```

Move them to a server, then check if they work.

```{r fig.height=6}
leaflet::leaflet()  %>% 
  leaflet::addTiles(group = "OpenStreetMap", layerId = "OSM") %>% 
  leaflet::addTiles(urlTemplate = "https://giorgiocomai.eu/testzone/sibiu_tiles_16/{z}/{x}/{-y}.png",
                    group = "Sibiu 1934",
                    layerId = "Sibiu 1934") %>% 
  setView(lng = 24.1519202, lat = 45.7973912, zoom = 14) %>% 
  addLayersControl(baseGroups = c("OpenStreetMap"),
                   overlayGroups = "Sibiu 1934")
  

```

## Combo side by side

```{r}
base <- leaflet::leaflet()  %>% 
  addProviderTiles(providers$OpenStreetMap.Mapnik, group = "Base map") %>% 
  addProviderTiles(providers$Esri.WorldImagery, group = "Satellite") %>% 
 # leaflet::addTiles(group = "OpenStreetMap", layerId = "OpenStreetMap") %>% 
  setView(lng = 24.1519202, lat = 45.7973912, zoom = 14) %>% 
  addLayersControl(baseGroups = c("Base map", "Satellite")) 

sibiu1934 <- leaflet::leaflet()  %>% 
  leaflet::addTiles(urlTemplate = "https://giorgiocomai.eu/testzone/sibiu_tiles_18/{z}/{x}/{-y}.png",
                    group = "Sibiu 1934",
                    layerId = "Sibiu 1934") %>% 
  setView(lng = 24.1519202, lat = 45.7973912, zoom = 14)

combo <- leafsync::sync(sibiu1934, base)
```

```{r fig.height=6, fig.width=10}
combo
```