nc_extended_rotating/init.lua

local minetest, vector, nodecore, include
    = minetest, vector, nodecore, include

local hud     = include("hud")
local rotate  = include("rotate")
local utility = include("utility")

-- TODO: Add crosshair indicators for rotating around edges.
-- TODO: Register only the nodes that should be rotatable.
-- TODO: Replace `on_rightclick` of intended nodes.
-- TODO: Add some more comments.

-- Distance at which we want to rotate by "pushing" on an edge.
local EDGE_DISTANCE = 1.5 / 16 -- 1.5 texels (at 16² texture resolution)

local rotating_state = {}

nodecore.register_playerstep({
    label = "extended rotating update",
    action = function(player, player_data)
        local name  = player:get_player_name()
        local state = {}; rotating_state[name] = state

        local pointed_thing = player_data.raycast()
        if (not pointed_thing) or pointed_thing.type ~= "node" then return nil end

        state.pos  = pointed_thing.under
        state.node = minetest.get_node(state.pos)
        if not rotate.is_rotatable(state.node) then return end

        if vector.equals(pointed_thing.above, pointed_thing.under) then return end
        state.face = pointed_thing.above - pointed_thing.under

        local edge, distance = utility.find_closest_edge(state.node, pointed_thing)
        if edge and distance > EDGE_DISTANCE then
            state.axis = state.face
            state.mode = "face"
        else
            state.axis = state.face:cross(edge):normalize():round()
            state.mode = "edge"
        end

        state.invert = player:get_player_control().sneak
        hud.update_player_hud(player, state)
    end,
})

minetest.register_on_leaveplayer(function(player)
    local name = player:get_player_name()
    rotating_state[name] = nil
end)


minetest.register_on_punchnode(function(pos, node, puncher, pointed_thing)
    if not minetest.is_player(puncher) then return end
    local name  = puncher:get_player_name()
    local state = rotating_state[name]
    if not state then return end

    -- Make sure we're still the same node that we raycasted in `playerstep`.
    if not vector.equals(pos, state.pos) then return end
    if node.name ~= state.node.name or node.param2 ~= state.node.param2 then return end

    local degrees = state.invert and 90 or -90
    rotate.rotate_node(state.pos, state.node, state.axis, degrees)
end)