Start work on glass tank.

mods/nc_optics/init.lua

@@ -11,3 +11,4 @@ include("lens")
 include("prism")
 include("cooking")
 include("crafting")
+include("shelf")

mods/nc_optics/shelf.lua

@@ -0,0 +1,39 @@
+-- LUALOCALS < ---------------------------------------------------------
+local minetest, nodecore
+    = minetest, nodecore
+-- LUALOCALS > ---------------------------------------------------------
+
+local modname = minetest.get_current_modname()
+
+local po = 0.5
+local no = -0.5
+local pi = 7/16
+local ni = -7/16
+minetest.register_node(modname .. ":shelf", {
+		description = "Glass Tank",
+		drawtype = "nodebox",
+		node_box = nodecore.fixedbox(
+			{no, no, no, po, ni, po},
+			{no, no, no, po, po, ni},
+			{no, no, pi, po, po, po},
+			{no, no, no, ni, po, po},
+			{pi, no, no, po, po, po}
+		),
+		tiles = {modname .. "_glass_glare.png^" .. modname
+			.. "_glass_edges.png^(nc_lode_annealed.png^[mask:"
+			.. modname .. "_tank_mask.png)"},
+		selection_box = nodecore.fixedbox(),
+		collision_box = nodecore.fixedbox(),
+		groups = {
+			silica = 1,
+			silica_clear = 1,
+			cracky = 3,
+			visinv = 1,
+			shelf = 1,
+			totable = 1
+		},
+		paramtype = "light",
+		sunlight_propagates = true,
+		sounds = nodecore.sounds("nc_optics_glassy"),
+		shelf_access = function(pt) return pt.above.y > pt.under.y end
+	})