Change folder structure: data files are now in a directory.

Also added a demo 400x400 map, that is overriden on pre-processing.

.gitignore

@@ -9,3 +9,4 @@ bounds_y
 dirs
 rivers
 unused/
+data/

README.md

@@ -18,6 +18,8 @@ The Python part relies on external libraries that you need to install:
 They are commonly found on `pip` or `conda` Python distributions.
 
 # Usage
+By default, the mod contains a demo 400x400 map (so you can start the game directly), but it is recommended that you run the pre-processing script to generate a new map before world creation, if you can.
+
 ## Pre-processing
 Run the script `terrain_rivers.py` via command line. You can optionally append the map size (by default 400). Example for a 1000x1000 map:
 ```
@@ -25,5 +27,10 @@ Run the script `terrain_rivers.py` via command line. You can optionally append t
 ```
 For a default 400x400 map, it should take between 1 and 2 minutes. It will generate 5 files directly in the mod folder, containing the map data.
 
+If you have `matplotlib` installed, the script `view_map.py` can be used to get a map preview. Example:
+```
+./view_map.py data/
+```
+
 ## Map generation
 Just create a Minetest world with `singlenode` mapgen, enable this mod and start the world. The data files are immediately copied in the world folder so you can re-generate them afterwards, it won't affect the old worlds.

demo_data/size

@@ -0,0 +1,2 @@
+401
+401

load.lua

@@ -1,4 +1,4 @@
-local worldpath = minetest.get_worldpath() .. "/"
+local worldpath = minetest.get_worldpath() .. "/river_data/"
 
 local function load_map(filename, bytes, signed, size)
 	local file = io.open(worldpath .. filename, 'r')

polygons.lua

@@ -1,15 +1,22 @@
 local modpath = minetest.get_modpath(minetest.get_current_modname()) .. '/'
-local worldpath = minetest.get_worldpath() .. '/'
+local mod_data_path = modpath .. 'data/'
+if not io.open(mod_data_path .. 'size', 'r') then
+	mod_data_path = modpath .. 'demo_data/'
+end
+
+local world_data_path = minetest.get_worldpath() .. '/river_data/'
+minetest.mkdir(world_data_path)
+
 local load_map = dofile(modpath .. 'load.lua')
 
 local function copy_if_needed(filename)
-	local wfilename = worldpath..filename
+	local wfilename = world_data_path..filename
 	local wfile = io.open(wfilename, 'r')
 	if wfile then
 		wfile:close()
 		return
 	end
-	local mfilename = modpath..filename
+	local mfilename = mod_data_path..filename
 	local mfile = io.open(mfilename, 'r')
 	local wfile = io.open(wfilename, 'w')
 	wfile:write(mfile:read("*all"))
@@ -18,7 +25,7 @@ local function copy_if_needed(filename)
 end
 
 copy_if_needed('size')
-local sfile = io.open(worldpath..'size')
+local sfile = io.open(world_data_path..'size')
 local X = tonumber(sfile:read('*l'))
 local Z = tonumber(sfile:read('*l'))
 sfile:close()

terrain_rivers.py

@@ -77,6 +77,9 @@ offset_x, offset_y = bounds.twist(bx, by, bounds.get_fixed(model.dirs))
 offset_x = np.clip(np.floor(offset_x * 256), -128, 127)
 offset_y = np.clip(np.floor(offset_y * 256), -128, 127)
 
+if not os.path.isdir('data'):
+    os.mkdir('data')
+os.chdir('data')
 # Save the files
 save(model.dem, 'dem', dtype='>i2')
 save(model.lakes, 'lakes', dtype='>i2')

view_map.py

@@ -27,6 +27,11 @@ def view_map(dem, lakes, rivers):
     plt.show()
 
 if __name__ == "__main__":
+    import sys
+    import os
+    if len(sys.argv) > 1:
+        os.chdir(sys.argv[1])
+
     def load_map(name, dtype, shape):
         dtype = np.dtype(dtype)
         with open(name, 'rb') as f: