Allow using regular (non-formspec) HUD elements

README.md

@@ -52,6 +52,26 @@ The following elements are supported:
 
 All valid formspec elements not listed above are ignored.
 
+### Using normal HUD element definitions
+
+If you want features can't be implemented using formspecs, you can use a list
+of HUD elements (the tables sent to `hud_add`) instead. Example:
+
+```lua
+hud_fs.show_hud(player, "waypoints", {
+    {
+        hud_elem_type = "waypoint",
+        world_pos = {x = 0, y = 0, z = 0},
+        name = "Waypoint 1"
+    },
+    {
+        hud_elem_type = "waypoint",
+        world_pos = {x = 1, y = 2, z = 3},
+        name = "Waypoint 2"
+    }
+})
+```
+
 ### Advanced API
 
  - `hud_fs.set_scale(formname, scale)`: Sets the scale of the HUD.
@@ -92,6 +112,9 @@ Then don't use this mod. There are plenty of other HUD library mods around such
 as [hudlib](https://github.com/octacian/hudlib) and
 [panel_lib](https://gitlab.com/zughy-friends-minetest/panel_lib).
 
+Alternatively, the API provided by this mod accepts a list of HUD elements in
+place of a formspec.
+
 ## Performance
 
 If this mod becomes a performance bottleneck you can try the following things:

init.lua

@@ -251,9 +251,11 @@ local function render(tree, proto_ver, scale, z_index)
             end
             offset_x = -node.x * size_w
             offset_y = -node.y * size_h
-            -- return render_error('anchor[] not implemented')
         elseif nodes[node_type] then
             add_node(node_type, node)
+        elseif node_type == nil and node.hud_elem_type then
+            -- Pass through plain HUD elements
+            hud_elems[#hud_elems + 1] = node
         end
     end
 
@@ -280,9 +282,9 @@ local function compare_elems(old_elem, new_elem)
     for k, v in pairs(old_elem) do
         local v2 = new_elem[k]
         if type(v) == "table" and type(v2) == "table" then
-            -- Tables are guaranteed to be 2-dimensional vectors at the moment,
-            -- don't bother checking anything else to improve performance.
-            if v.x ~= v2.x or v.y ~= v2.y then
+            -- Tables are guaranteed to be vectors at the moment, don't bother
+            -- checking anything else to improve performance.
+            if v.x ~= v2.x or v.y ~= v2.y or v.z ~= v2.z then
                 differences[#differences + 1] = k
             end
         elseif v ~= v2 then