1 files changed, 125 insertions, 0 deletions
diff --git a/ch_core/interiors.lua b/ch_core/interiors.lua
new file mode 100644
index 0000000..c7b15a4
--- /dev/null
+++ b/ch_core/interiors.lua
@@ -0,0 +1,125 @@
+ch_core.open_submod("interiors", {})
+
+local normal = 0
+local passable = 1
+local evadable = 2
+
+minetest.register_on_mods_loaded(function()
+    local passable_drawtypes = {
+        airlike = true,
+        firelike = true,
+        flowingliquid = true,
+        liquid = true,
+        plantlike = true,
+        plantlike_rooted = true,
+        signlike = true,
+        torchlike = true,
+    }
+    for _, ndef in pairs(minetest.registered_nodes) do
+		if passable_drawtypes[ndef.drawtype or "normal"] then -- or ndef.sunlight_propagates == true
+            ndef._ch_interior = passable
+		else
+			local groups = ndef.groups
+            if groups == nil then
+                ndef._ch_interior = normal
+            elseif groups.leaves then
+                ndef._ch_interior = passable
+			elseif groups.tree then
+                ndef._ch_interior = evadable
+            else
+                ndef._ch_interior = normal
+			end
+		end
+	end
+end)
+
+local get_node = minetest.get_node
+local registered_nodes = minetest.registered_nodes
+
+local function has_passable_neighbour(pos)
+    local ndef
+	pos.x = pos.x - 1 -- -x
+    ndef = registered_nodes[get_node(pos).name]
+	if ndef ~= nil and ndef._ch_interior == passable then
+		return true
+	end
+	pos.z = pos.z - 1 -- -x -z
+    ndef = registered_nodes[get_node(pos).name]
+	if ndef ~= nil and ndef._ch_interior == passable then
+		return true
+	end
+	pos.x = pos.x + 1 -- -z
+    ndef = registered_nodes[get_node(pos).name]
+	if ndef ~= nil and ndef._ch_interior == passable then
+		return true
+	end
+	pos.x = pos.x + 1 -- +x -z
+    ndef = registered_nodes[get_node(pos).name]
+	if ndef ~= nil and ndef._ch_interior == passable then
+		return true
+	end
+	pos.z = pos.z + 1 -- +x
+    ndef = registered_nodes[get_node(pos).name]
+	if ndef ~= nil and ndef._ch_interior == passable then
+		return true
+	end
+	pos.z = pos.z + 1 -- +x +z
+    ndef = registered_nodes[get_node(pos).name]
+	if ndef ~= nil and ndef._ch_interior == passable then
+		return true
+	end
+	pos.x = pos.x - 1 -- +z
+    ndef = registered_nodes[get_node(pos).name]
+	if ndef ~= nil and ndef._ch_interior == passable then
+		return true
+	end
+	pos.x = pos.x - 1 -- -x +z
+    ndef = registered_nodes[get_node(pos).name]
+	if ndef ~= nil and ndef._ch_interior == passable then
+		return true
+	end
+	return false
+end
+
+--[[
+    Prozkoumá, zda se zadaná pozice jeví být v interiéru.
+    Při použití na hráčskou postavu (player:get_pos()) je potřeba k souřadnici y přičíst 0.5.
+]]
+function ch_core.is_in_interior(pos)
+    local nlight = minetest.get_natural_light(pos, 0.5) or 0
+    if nlight <= 0 then
+        return true
+    elseif nlight >= minetest.LIGHT_MAX then
+        return false
+    else
+        local ndef, ntype
+        local ray = minetest.raycast(pos, vector.offset(pos, 0, 20, 0), false, false)
+        for pointed_thing in ray do
+            if pointed_thing.type == "node" then
+                ndef = registered_nodes[get_node(pointed_thing.under)]
+                if ndef == nil then
+                    return true -- under unknown node => interior
+                end
+                ntype = ndef._ch_interior
+                if ntype ~= passable then
+                    if ntype == evadable then
+                        local pos2 = vector.offset(pointed_thing.under, 0, 1, 0)
+                        ndef = registered_nodes[get_node(pos2).name]
+                        if ndef == nil or ndef._ch_interior == evadable then
+                            return true -- under two evadable nodes => interior
+                        end
+                        pos2.y = pointed_thing.under.y
+                        if not has_passable_neighbour(pointed_thing.under) then
+                            return true -- under evadable node with no passable neighbour => interior
+                        end
+                    else
+                        return true -- under full node => interior
+                    end
+                end
+            end
+        end
+        return false
+    end
+end
+
+ch_core.close_submod("interiors")