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

doc/lua_api.md

@@ -6183,6 +6183,17 @@ Environment access
     * increase level of leveled node by level, default `level` equals `1`
     * if `totallevel > maxlevel`, returns rest (`total-max`)
     * `level` must be between -127 and 127
+* `minetest.get_node_boxes(box_type, pos, [node])`
+    * `box_type` must be `"node_box"`, `"collision_box"` or `"selection_box"`.
+    * `pos` must be a node position.
+    * `node` can be a table in the form `{name=string, param1=number, param2=number}`.
+      If `node` is `nil`, the actual node at `pos` is used instead.
+    * Resolves any facedir-rotated boxes, connected boxes and the like into
+      actual boxes.
+    * Returns a list of boxes in the form
+      `{{x1, y1, z1, x2, y2, z2}, {x1, y1, z1, x2, y2, z2}, ...}`. Coordinates
+      are relative to `pos`.
+    * See also: [Node boxes](#node-boxes)
 * `minetest.fix_light(pos1, pos2)`: returns `true`/`false`
     * resets the light in a cuboid-shaped part of
       the map and removes lighting bugs.

games/devtest/mods/testtools/init.lua

@@ -6,6 +6,7 @@ testtools = {}
 dofile(minetest.get_modpath("testtools") .. "/light.lua")
 dofile(minetest.get_modpath("testtools") .. "/privatizer.lua")
 dofile(minetest.get_modpath("testtools") .. "/particles.lua")
+dofile(minetest.get_modpath("testtools") .. "/node_box_visualizer.lua")
 
 local pointabilities_nodes = {
 	nodes = {

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,
+})

src/script/common/c_content.cpp

@@ -1110,7 +1110,7 @@ void push_nodebox(lua_State *L, const NodeBox &box)
 		case NODEBOX_FIXED:
 			lua_pushstring(L, "fixed");
 			lua_setfield(L, -2, "type");
-			push_box(L, box.fixed);
+			push_aabb3f_vector(L, box.fixed);
 			lua_setfield(L, -2, "fixed");
 			break;
 		case NODEBOX_WALLMOUNTED:
@@ -1127,17 +1127,17 @@ void push_nodebox(lua_State *L, const NodeBox &box)
 			lua_pushstring(L, "connected");
 			lua_setfield(L, -2, "type");
 			const auto &c = box.getConnected();
-			push_box(L, c.connect_top);
+			push_aabb3f_vector(L, c.connect_top);
 			lua_setfield(L, -2, "connect_top");
-			push_box(L, c.connect_bottom);
+			push_aabb3f_vector(L, c.connect_bottom);
 			lua_setfield(L, -2, "connect_bottom");
-			push_box(L, c.connect_front);
+			push_aabb3f_vector(L, c.connect_front);
 			lua_setfield(L, -2, "connect_front");
-			push_box(L, c.connect_back);
+			push_aabb3f_vector(L, c.connect_back);
 			lua_setfield(L, -2, "connect_back");
-			push_box(L, c.connect_left);
+			push_aabb3f_vector(L, c.connect_left);
 			lua_setfield(L, -2, "connect_left");
-			push_box(L, c.connect_right);
+			push_aabb3f_vector(L, c.connect_right);
 			lua_setfield(L, -2, "connect_right");
 			// half the boxes are missing here?
 			break;
@@ -1148,16 +1148,6 @@ void push_nodebox(lua_State *L, const NodeBox &box)
 	}
 }
 
-void push_box(lua_State *L, const std::vector<aabb3f> &box)
-{
-	lua_createtable(L, box.size(), 0);
-	u8 i = 1;
-	for (const aabb3f &it : box) {
-		push_aabb3f(L, it);
-		lua_rawseti(L, -2, i++);
-	}
-}
-
 /******************************************************************************/
 void push_palette(lua_State *L, const std::vector<video::SColor> *palette)
 {

src/script/common/c_content.h

@@ -83,9 +83,6 @@ void               push_content_features     (lua_State *L,
 
 void               push_nodebox              (lua_State *L,
                                               const NodeBox &box);
-void               push_box                  (lua_State *L,
-                                              const std::vector<aabb3f> &box);
-
 void               push_palette              (lua_State *L,
                                               const std::vector<video::SColor> *palette);
 

src/script/common/c_converter.cpp

@@ -364,20 +364,20 @@ aabb3f read_aabb3f(lua_State *L, int index, f32 scale)
 	return box;
 }
 
-void push_aabb3f(lua_State *L, aabb3f box)
+void push_aabb3f(lua_State *L, aabb3f box, f32 divisor)
 {
 	lua_createtable(L, 6, 0);
-	lua_pushnumber(L, box.MinEdge.X);
+	lua_pushnumber(L, box.MinEdge.X / divisor);
 	lua_rawseti(L, -2, 1);
-	lua_pushnumber(L, box.MinEdge.Y);
+	lua_pushnumber(L, box.MinEdge.Y / divisor);
 	lua_rawseti(L, -2, 2);
-	lua_pushnumber(L, box.MinEdge.Z);
+	lua_pushnumber(L, box.MinEdge.Z / divisor);
 	lua_rawseti(L, -2, 3);
-	lua_pushnumber(L, box.MaxEdge.X);
+	lua_pushnumber(L, box.MaxEdge.X / divisor);
 	lua_rawseti(L, -2, 4);
-	lua_pushnumber(L, box.MaxEdge.Y);
+	lua_pushnumber(L, box.MaxEdge.Y / divisor);
 	lua_rawseti(L, -2, 5);
-	lua_pushnumber(L, box.MaxEdge.Z);
+	lua_pushnumber(L, box.MaxEdge.Z / divisor);
 	lua_rawseti(L, -2, 6);
 }
 
@@ -409,6 +409,16 @@ std::vector<aabb3f> read_aabb3f_vector(lua_State *L, int index, f32 scale)
 	return boxes;
 }
 
+void push_aabb3f_vector(lua_State *L, const std::vector<aabb3f> &boxes, f32 divisor)
+{
+	lua_createtable(L, boxes.size(), 0);
+	int i = 1;
+	for (const aabb3f &box : boxes) {
+		push_aabb3f(L, box, divisor);
+		lua_rawseti(L, -2, i++);
+	}
+}
+
 size_t read_stringlist(lua_State *L, int index, std::vector<std::string> *result)
 {
 	if (index < 0)

src/script/common/c_converter.h

@@ -110,11 +110,13 @@ void                push_v2s16          (lua_State *L, v2s16 p);
 void                push_v2s32          (lua_State *L, v2s32 p);
 void                push_v2u32          (lua_State *L, v2u32 p);
 void                push_v3s16          (lua_State *L, v3s16 p);
-void                push_aabb3f         (lua_State *L, aabb3f box);
+void                push_aabb3f         (lua_State *L, aabb3f box, f32 divisor = 1.0f);
 void                push_ARGB8          (lua_State *L, video::SColor color);
 void                pushFloatPos        (lua_State *L, v3f p);
 void                push_v3f            (lua_State *L, v3f p);
 void                push_v2f            (lua_State *L, v2f p);
+void                push_aabb3f_vector  (lua_State *L, const std::vector<aabb3f> &boxes,
+                                         f32 divisor = 1.0f);
 
 void                warn_if_field_exists(lua_State *L, int table,
                                          const char *fieldname,

src/script/lua_api/l_env.cpp

@@ -562,6 +562,40 @@ int ModApiEnv::l_add_node_level(lua_State *L)
 	return 1;
 }
 
+// get_node_boxes(box_type, pos, [node]) -> table
+// box_type = string
+// pos = {x=num, y=num, z=num}
+// node = {name=string, param1=num, param2=num} or nil
+int ModApiEnv::l_get_node_boxes(lua_State *L)
+{
+	GET_ENV_PTR;
+
+	std::string box_type = luaL_checkstring(L, 1);
+	v3s16 pos = read_v3s16(L, 2);
+	MapNode n;
+	if (lua_istable(L, 3))
+		n = readnode(L, 3);
+	else
+		n = env->getMap().getNode(pos);
+
+	u8 neighbors = n.getNeighbors(pos, &env->getMap());
+	const NodeDefManager *ndef = env->getGameDef()->ndef();
+
+	std::vector<aabb3f> boxes;
+	if (box_type == "node_box")
+		n.getNodeBoxes(ndef, &boxes, neighbors);
+	else if (box_type == "collision_box")
+		n.getCollisionBoxes(ndef, &boxes, neighbors);
+	else if (box_type == "selection_box")
+		n.getSelectionBoxes(ndef, &boxes, neighbors);
+	else
+		luaL_error(L, "get_node_boxes: box_type is invalid. Allowed values: \"node_box\", \"collision_box\", \"selection_box\"");
+
+	push_aabb3f_vector(L, boxes, BS);
+
+	return 1;
+}
+
 // find_nodes_with_meta(pos1, pos2)
 int ModApiEnv::l_find_nodes_with_meta(lua_State *L)
 {
@@ -1456,6 +1490,7 @@ void ModApiEnv::Initialize(lua_State *L, int top)
 	API_FCT(get_node_level);
 	API_FCT(set_node_level);
 	API_FCT(add_node_level);
+	API_FCT(get_node_boxes);
 	API_FCT(add_entity);
 	API_FCT(find_nodes_with_meta);
 	API_FCT(get_meta);

src/script/lua_api/l_env.h

@@ -120,6 +120,12 @@ private:
 	// pos = {x=num, y=num, z=num}
 	static int l_add_node_level(lua_State *L);
 
+	// get_node_boxes(box_type, pos, [node]) -> table
+	// box_type = string
+	// pos = {x=num, y=num, z=num}
+	// node = {name=string, param1=num, param2=num} or nil
+	static int l_get_node_boxes(lua_State *L);
+
 	// find_nodes_with_meta(pos1, pos2)
 	static int l_find_nodes_with_meta(lua_State *L);