Add Lua API function to resolve node/collision/selection boxes (#13964)

games/devtest/mods/testtools/node_box_visualizer.lua

@@ -0,0 +1,79 @@
+local S = minetest.get_translator("testtools")
+
+minetest.register_entity("testtools:visual_box", {
+	initial_properties = {
+		visual = "cube",
+		textures = {
+			"blank.png", "blank.png", "blank.png",
+			"blank.png", "blank.png", "blank.png",
+		},
+		use_texture_alpha = true,
+		physical = false,
+		pointable = false,
+		static_save = false,
+	},
+
+	on_activate = function(self)
+		self.timestamp = minetest.get_us_time() + 5000000
+	end,
+
+	on_step = function(self)
+		if minetest.get_us_time() >= self.timestamp then
+			self.object:remove()
+		end
+	end,
+})
+
+local BOX_TYPES = {"node_box", "collision_box", "selection_box"}
+local DEFAULT_BOX_TYPE = "selection_box"
+
+local function visualizer_on_use(itemstack, user, pointed_thing)
+	if pointed_thing.type ~= "node" then
+		return
+	end
+
+	local meta = itemstack:get_meta()
+	local box_type = meta:get("box_type") or DEFAULT_BOX_TYPE
+
+	local result = minetest.get_node_boxes(box_type, pointed_thing.under)
+	local t = "testtools_visual_" .. box_type .. ".png"
+
+	for _, box in ipairs(result) do
+		local box_min = pointed_thing.under + vector.new(box[1], box[2], box[3])
+		local box_max = pointed_thing.under + vector.new(box[4], box[5], box[6])
+		local box_center = (box_min + box_max) / 2
+		local obj = minetest.add_entity(box_center, "testtools:visual_box")
+		if not obj then
+			break
+		end
+		obj:set_properties({
+			textures = {t, t, t, t, t, t},
+			-- Add a small offset to avoid Z-fighting.
+			visual_size = vector.add(box_max - box_min, 0.01),
+		})
+	end
+end
+
+local function visualizer_on_place(itemstack, placer, pointed_thing)
+	local meta = itemstack:get_meta()
+	local prev_value = meta:get("box_type") or DEFAULT_BOX_TYPE
+	local prev_index = table.indexof(BOX_TYPES, prev_value)
+	assert(prev_index ~= -1)
+
+	local new_value = BOX_TYPES[(prev_index % #BOX_TYPES) + 1]
+	meta:set_string("box_type", new_value)
+	minetest.chat_send_player(placer:get_player_name(), S("[Node Box Visualizer] box_type = @1", new_value))
+
+	return itemstack
+end
+
+minetest.register_tool("testtools:node_box_visualizer", {
+	description = S("Node Box Visualizer") .. "\n" ..
+		S("Punch: Show node/collision/selection boxes of the pointed node") .. "\n" ..
+		S("Place: Change selected box type (default: selection box)"),
+	inventory_image = "testtools_node_box_visualizer.png",
+	groups = { testtool = 1, disable_repair = 1 },
+	on_use = visualizer_on_use,
+	on_place = visualizer_on_place,
+	on_secondary_use = visualizer_on_place,
+})