Clean up a few functions and get ready for new features.

mapgen.lua

@@ -7,20 +7,7 @@ function init_mapgen()
 
    -- Metadata for different biomes
    -- frequencies don't have to add up to 100, but they should by convention
-   --
-   -- Sprites are:
-   --  * 2 - grass
-   --  * 3 - bush
-   --  * 4 - tree
-   --  * 5 - red flowers
-   --  * 6 - pink flowers
-   --  * 7 - mushrooms
-   --  * 8 - big mushroom
-   --  * 9 - sand
-   --  * 10 - cactus with flower
-   --  * 11 - pebbles
-   --  * 12 - rock
-   --  * 13 - cactus
+   -- tile_frequencies tuples are {frequency, sprite_index}, see index_map.md
    biome_data = {
       grassland = {
          biome_frequency = 75,
@@ -92,17 +79,17 @@ end
 
 -- determines which biome a given world map position should be,
 -- returns the object out of the biome_data table
-function get_biome(pos)
+function get_biome_name(pos)
    local biome_pos = calculate_biome_pos(pos)
    local uid = generate_uid(biome_pos)
-   local biome_name = biome_metadata[(uid % #biome_metadata) + 1]
-   return biome_data[biome_name]
+   return biome_metadata[(uid % #biome_metadata) + 1]
 end
 
 -- determine what sprite to render for a given position.
 -- todo: this needs the ability to have a list of 'changed' tiles to check against.
 function get_tile(pos)
-   local biome = get_biome(pos)
+   local biome_name = get_biome_name(pos)
+   local biome = biome_data[biome_name]
    local uid = generate_uid(pos)
 
    return biome["tile_lookup"][(uid % #biome["tile_lookup"]) + 1]