Render mcl_farming plant stems 1/16 node lower

This patch shifts mcl_farming nodes that represent a stem 1/16 nodes
downwards. It also replaces the plantlike drawtype of mcl_farming nodes
that represent an unconnected stem (x) with a nodebox drawtype that
looks like a plus (+), as Minetest has no option to rotate nodeboxes.
The goal is to remove the gap between plants and farming soil with a
node height of 15/16.

This patch affects melon stem and pumpkin stem nodes.

mods/ITEMS/mcl_farming/melon.lua

@@ -91,16 +91,18 @@ for s=1,7 do
 		_doc_items_longdesc = longdesc,
 		paramtype = "light",
 		walkable = false,
-		drawtype = "plantlike",
+		drawtype = "nodebox",
+		node_box = mcl_farming:get_plantlike_plus_nodebox(),
 		sunlight_propagates = true,
 		drop = stem_drop,
-		tiles = {texture},
+		tiles = { mcl_farming:align_plantlike_nodebox_texture(texture) },
+		use_texture_alpha = "clip",
 		wield_image = texture,
 		inventory_image = texture,
 		selection_box = {
 			type = "fixed",
 			fixed = {
-				{-0.15, -0.5, -0.15, 0.15, -0.5+h, 0.15}
+				{-0.15, -9/16, -0.15, 0.15, -9/16+h, 0.15}
 			},
 		},
 		groups = {dig_immediate=3, not_in_creative_inventory=1, plant=1,attached_node=1, dig_by_water=1,destroy_by_lava_flow=1, plant_melon_stem=s},

mods/ITEMS/mcl_farming/pumpkin.lua

@@ -63,16 +63,18 @@ for s=1,7 do
 		_doc_items_longdesc = longdesc,
 		paramtype = "light",
 		walkable = false,
-		drawtype = "plantlike",
+		drawtype = "nodebox",
+		node_box = mcl_farming:get_plantlike_plus_nodebox(),
 		sunlight_propagates = true,
 		drop = stem_drop,
-		tiles = {texture},
+		tiles = { mcl_farming:align_plantlike_nodebox_texture(texture) },
+		use_texture_alpha = "clip",
 		inventory_image = texture,
 		wield_image = texture,
 		selection_box = {
 			type = "fixed",
 			fixed = {
-				{-0.15, -0.5, -0.15, 0.15, -0.5+h, 0.15}
+				{-0.15, -9/16, -0.15, 0.15, -9/16+h, 0.15}
 			},
 		},
 		groups = {dig_immediate=3, not_in_creative_inventory=1, plant=1,attached_node=1, dig_by_water=1,destroy_by_lava_flow=1,},

mods/ITEMS/mcl_farming/shared_functions.lua

@@ -265,7 +265,7 @@ function mcl_farming:add_gourd(full_unconnected_stem, connected_stem_basename, s
 		stem_def.selection_box = {
 			type = "fixed",
 			fixed = {
-				{-0.15, -0.5, -0.15, 0.15, 0.5, 0.15}
+				{-0.15, -9/16, -0.15, 0.15, 7/16, 0.15}
 			},
 		}
 	end
@@ -273,7 +273,20 @@ function mcl_farming:add_gourd(full_unconnected_stem, connected_stem_basename, s
 		stem_def.paramtype = "light"
 	end
 	if not stem_def.drawtype then
-		stem_def.drawtype = "plantlike"
+		stem_def.drawtype = "nodebox"
+	end
+	if not stem_def.node_box then
+		stem_def.node_box = mcl_farming:get_plantlike_plus_nodebox()
+	end
+	if stem_def.tiles then
+		for i=1,#stem_def.tiles do
+			stem_def.tiles[i] = mcl_farming:align_plantlike_nodebox_texture(
+				stem_def.tiles[i]
+			)
+		end
+	end
+	if not stem_def.use_texture_alpha then
+		stem_def.use_texture_alpha = "clip"
 	end
 	if stem_def.walkable == nil then
 		stem_def.walkable = false
@@ -300,6 +313,9 @@ function mcl_farming:add_gourd(full_unconnected_stem, connected_stem_basename, s
 	minetest.register_node(stem_itemstring, stem_def)
 
 	-- Register connected stems
+	local connected_stem_texture = mcl_farming:align_plantlike_nodebox_texture(
+		connected_stem_texture
+	)
 	local connected_stem_tiles = {
 		{ "blank.png", --top
 		"blank.png", -- bottom
@@ -331,16 +347,16 @@ function mcl_farming:add_gourd(full_unconnected_stem, connected_stem_basename, s
 		}
 	}
 	local connected_stem_nodebox = {
-		{-0.5, -0.5, 0, 0.5, 0.5, 0},
+		{-0.5, -9/16, 0, 0.5, 7/16, 0},
-		{-0.5, -0.5, 0, 0.5, 0.5, 0},
+		{-0.5, -9/16, 0, 0.5, 7/16, 0},
-		{0, -0.5, -0.5, 0, 0.5, 0.5},
+		{0, -9/16, -0.5, 0, 7/16, 0.5},
-		{0, -0.5, -0.5, 0, 0.5, 0.5},
+		{0, -9/16, -0.5, 0, 7/16, 0.5},
 	}
 	local connected_stem_selectionbox = {
-		{-0.1, -0.5, -0.1, 0.5, 0.2, 0.1},
+		{-0.1, -9/16, -0.1, 0.5, 0.2 - 1/16, 0.1},
-		{-0.5, -0.5, -0.1, 0.1, 0.2, 0.1},
+		{-0.5, -9/16, -0.1, 0.1, 0.2 - 1/16, 0.1},
-		{-0.1, -0.5, -0.1, 0.1, 0.2, 0.5},
+		{-0.1, -9/16, -0.1, 0.1, 0.2 - 1/16, 0.5},
-		{-0.1, -0.5, -0.5, 0.1, 0.2, 0.1},
+		{-0.1, -9/16, -0.5, 0.1, 0.2 - 1/16, 0.1},
 	}
 
 	for i=1, 4 do
@@ -469,6 +485,19 @@ minetest.register_lbm({
 	end,
 })
 
+-- This function returns a nodebox that imitates a plantlike plus (+)
+-- drawtype, but is shifted 1/16 lower, into the empty space above
+-- farming soil. The regular plantlike drawtype can not do this.
+function mcl_farming:get_plantlike_plus_nodebox()
+	return {
+		type = "fixed",
+		fixed = {
+			{ 0, -9/16, -0.15, 0, 7/16, 0.15 },
+			{ -0.15, -9/16, 0, 0.15, 7/16, 0 }
+		}
+	}
+end
+
 -- This function returns a nodebox that imitates a plantlike grid (#)
 -- drawtype, but is shifted 1/16 lower, into the empty space above
 -- farming soil. The regular plantlike drawtype can not do this.