Add Lua API for mod interop

API.md

@@ -82,3 +82,20 @@ Dripstone blocks cannot be crafted.
 All other sizes can be crafted using dripstone spikes. You can upgrade a
 dripstone item by surrounding it with (the same type of) dripstone spikes.
 Huge dripstone cannot be upgraded to a dripstone block, however.
+
+## Lua modders
+
+The following API functions are exposed for you to manipulate this mod with.
+
+- `noordstar_dripstone.add_lava_source(nodename)` Add a node name that the mod
+should consider a source of lava droplets above dripstone blocks.
+- `noordstar_dripstone.add_water_source(nodename)` Add a node name that the mod
+should consider a source of water droplets above dripstone blocks.
+- `noordstar_dripstone.add_lava_catcher(oldnodename, newnodename)` Register a
+node that can catch lava droplets to transform into a new node, such as a
+cauldron.
+- `noordstar_dripstone.add_water_catcher(oldnodename, newnodename)` Register a
+node that can catch water droplets to transform into a new node, such as a
+cauldron.
+
+All input values are strings in this API.

init.lua

@@ -1,56 +1,4 @@
-noordstar_dripstone = {
-    -- Nodes that the mod should consider as sources to extract water from
-    water_nodes =
-        { "default:river_water_source"
-        , "default:water_source"
-        , "mcl_core:water_source"
-        , "mclx_core:river_water_source"
-        }
-    
-    -- Nodes that the mod should consider as sources to extract lava from
-    , lava_nodes =
-        { "default:lava_source"
-        , "mcl_core:lava_source"
-        }
-}
-
-local modpath = minetest.get_modpath(minetest.get_current_modname())
-
-local function load(module_name)
-    return dofile(modpath .. "/lua/" .. module_name .. ".lua")
-end
-local function schem(module_name)
-    return dofile(modpath .. "/schematics/" .. module_name .. ".lua")
-end
-
--- Create a node box for any given dripstone size.
--- Size 8 is a normal block size
-local function nodebox_of_size(size)
-    if size >= 8 then
-        return nil
-    else
-        return {
-            type = "fixed",
-            fixed = {
-                { - size / 16, -0.5, - size / 16, size / 16, 0.5, size / 16 },
-            },
-        }
-    end
-end
-
-local function nodebox_type(size)
-    if size >= 8 then
-        return "normal"
-    else
-        return "nodebox"
-    end
-end
-
--- Sounds
-local dripstone_sounds = nil
-if mcl_sounds then
-    dripstone_sounds = mcl_sounds.node_sound_stone_defaults()
-end
+noordstar_dripstone = {}
 
 -- Constants
 local speed_factor = 30
@@ -93,6 +41,82 @@ local watered_dripstone_small = "noordstar_dripstone:small_watered_dripstone"
 local watered_dripstone_tiny = "noordstar_dripstone:tiny_watered_dripstone"
 local watered_dripstone_spike = "noordstar_dripstone:watered_dripstone_spike"
 
+local internal = {
+    -- Nodes that the mod should consider as sources to extract water from
+    water_nodes =
+        { "default:river_water_source"
+        , "default:water_source"
+        , "mcl_core:water_source"
+        , "mclx_core:river_water_source"
+        },
+    
+    -- Nodes that the mod should consider as sources to extract lava from
+    lava_nodes =
+        { "default:lava_source"
+        , "mcl_core:lava_source"
+        },
+
+    -- Nodes that can catch a lava droplet instead of letting a spike grow on top
+    lava_cauldrons = {
+        { from = dry_dripstone_spike, to = molten_dripstone_spike },
+        { from = "mcl_cauldrons:cauldron", to = "mcl_cauldrons:cauldron_1_lava" },
+        { from = "mcl_cauldrons:cauldron_1_lava", to = "mcl_cauldrons:cauldron_2_lava" },
+        { from = "mcl_cauldrons:cauldron_2_lava", to = "mcl_cauldrons:cauldron_3_lava" },
+    },
+
+    -- Nodes that can catch a water droplet instead of letting a spike grow on top
+    water_cauldrons = {
+        { from = dry_dripstone_spike, to = watered_dripstone_spike },
+        { from = "mcl_cauldrons:cauldron", to = "mcl_cauldrons:cauldron_1" },
+        { from = "mcl_cauldrons:cauldron_1", to = "mcl_cauldrons:cauldron_2" },
+        { from = "mcl_cauldrons:cauldron_2", to = "mcl_cauldrons:cauldron_3" },
+    }
+}
+
+function noordstar_dripstone.add_lava_source(nodename)
+    table.insert(internal.lava_nodes)
+end
+function noordstar_dripstone.add_water_source(nodename)
+    table.insert(internal.water_nodes, nodename)
+end
+
+function noordstar_dripstone.add_lava_catcher(nodename, newnodename)
+    table.insert(internal.lava_cauldrons, { from = nodename, to = newnodename })
+end
+function noordstar_dripstone.add_water_catcher(nodename, newnodename)
+    table.insert(internal.water_cauldrons, { from = nodename, to = newnodename })
+end
+
+
+-- Create a node box for any given dripstone size.
+-- Size 8 is a normal block size
+local function nodebox_of_size(size)
+    if size >= 8 then
+        return nil
+    else
+        return {
+            type = "fixed",
+            fixed = {
+                { - size / 16, -0.5, - size / 16, size / 16, 0.5, size / 16 },
+            },
+        }
+    end
+end
+
+local function nodebox_type(size)
+    if size >= 8 then
+        return "normal"
+    else
+        return "nodebox"
+    end
+end
+
+-- Sounds
+local dripstone_sounds = nil
+if mcl_sounds then
+    dripstone_sounds = mcl_sounds.node_sound_stone_defaults()
+end
+
 -- Trickle down config
 
 local lava_trickle_down = {
@@ -171,20 +195,8 @@ local water_trickle_down_spike = {
     { from = molten_dripstone_spike, to = hardened_dripstone_spike },
 }
 
-local lava_drop_down = {
-    { from = dry_dripstone_spike, to = molten_dripstone_spike },
-    { from = "mcl_cauldrons:cauldron", to = "mcl_cauldrons:cauldron_1_lava" },
-    { from = "mcl_cauldrons:cauldron_1_lava", to = "mcl_cauldrons:cauldron_2_lava" },
-    { from = "mcl_cauldrons:cauldron_2_lava", to = "mcl_cauldrons:cauldron_3_lava" },
-}
-local water_drop_down = {
-    { from = dry_dripstone_spike, to = watered_dripstone_spike },
-    { from = "mcl_cauldrons:cauldron", to = "mcl_cauldrons:cauldron_1" },
-    { from = "mcl_cauldrons:cauldron_1", to = "mcl_cauldrons:cauldron_2" },
-    { from = "mcl_cauldrons:cauldron_2", to = "mcl_cauldrons:cauldron_3" },
-}
-
 -- Tiles for dripstone
+
 local dry_dripstone_tiles =
     { "noordstar_dripstone_dripstone_top.png"
     , "noordstar_dripstone_dripstone_top.png"
@@ -206,6 +218,8 @@ local watered_dripstone_tiles =
     , "noordstar_dripstone_watered_dripstone_side.png"
     }
 
+-- Register dripstone nodes
+
 local function make_dripstone(name, desc, longdesc, tiles, drop, size)
     local sunlight_propagates = nil
     if size < 8 then