Tidy up readme

README.md

@@ -3,14 +3,19 @@
 Leaftest consists of a bash script that uses [minetestmapper](https://github.com/Rogier-5/minetest-mapper-cpp) to display the map on a leaflet based zoomable sloppy map. As an example, see [VanessaE survival server's map](https://daconcepts.com/vanessa/hobbies/minetest/worldmaps/Survival_World/map.html).
 
 The map is generated in chunks through many invocations of `minetestmapper` instead of one invocation and large file thats cropped later, so that memory requirements for all tools are unrelated to the map size.
-##Dependencies
-You will need:
+
+### Dependencies
+
+Ensure that you have:
 
     -bash
     -imagemagick
-    -a web server of some sort
     -minetestmapper
 
+If you want to host the map on the world wide web, you'll need a web server.
+
+### Running the mapper script
+
 Get a clone:
 ```
 git clone --recursive https://github.com/est31/leaftest.git
@@ -21,15 +26,19 @@ To start the mapping, do:
 MAPPERDIR=dir/containing/minetestmapper ./mapper.sh path/to/world spawnx,spawny dimension
 ```
 
-If you have additional parameters for `minetestmapper`, like a `colors.txt` path of your choice, you can add them to the `MAPPERPARAMS` variable.
-
 The `dimension` number specifies the width and height of the map that should be rendered, centering with your spawn position. `dimension` should be a multiple of 8*256 =  2048, 6144 is a good starting value.
 
+The list of parameters passed via the invocation is fixed,
+but you can use the environment variable mechanism
+to pass further options to the mapper script:
+
+* `MAPPERDIR` must point to the path that contains the minetestmapper executable
+* `MAPPERPARAMS` can be used to pass custom parameters to the `minetestmapper` invocation
+* `JOBNUM` can be used to enable parallelisation. Set it to a positive number to
+
 After mapping has finished, you can open the `www/map.html` file. If you want to publish your results, you can either symlink the `www` directory into your `/var/www` directory, or copy it. Due to usage of relative symlinks, you should use `rsync -L`, so that the copied directory doesn't contain symlinks.
 
-You can use the `JOBNUM` environment variable to control the number of parallel jobs used for creating the tiles.
-
 ##License
-Copyright (c) 2015 est31, License: MIT.
+Copyright (c) 2015-2016 est31, License: MIT.
 
 Parts base on unilicensed script from [LibertyLand](http://www.ayntest.net/pages/liberty-land-map.html) minetest server, [github here](https://github.com/ayntest/ayntest.github.io).