uniham/system/register_hammer.lua

-- Localize
local use_hammer = uniham.use_hammer


-- Register a new hammer
--
-- definition = {
--   name = 'Name of the hammer',
--   head = 'head_material_texture.png',
--   craft = 'crafting:material',
--   on_use = on_use_function,
--   uses = 123,
-- }
--
-- The `name` will be shown as tooltip on hovering the item in the inventory
-- and will be used as it is.
--
-- `head` is a texture that is used as base for the hammer head texture mask.
-- To change the mask textture packs need to add `uniham_head_mask.png` with
-- another file. All black pixels will become transparent.
--
-- With `craft` the material to craft the hammer from is defined. Hammers are
-- crafted all the same with the provided material for x and a stick for s
--
--   [ ][x][ ]
--   [ ][s][x]
--   [s][ ][ ]
--
-- The function provided via `on_use` gets three parameters when called by the
-- hammer’s on_use action: `itemstack`, `player`, and `pointed_thing`. All of
-- those three parameters are defined by Minetest’s API. The function has to
-- modify and return the itemstack as needed.
--
-- If no function is provided the default function (replace nodes by the table
-- provided as `uniham.use_hammer` in mod loading state).
--
-- `uses` is added as `_uniham.uses` to the hammer’s item definition and can
-- be used by the custom `on_use` function. The built-in function (replacing
-- nodes) calculates the `add_wear` value from this.
--
-- @param short_id   Unprefixed ID for the new hammer
-- @param definition Definition table as described
-- @see <https://dev.minetest.net/on_use#on_use>
-- @return void
uniham.register_hammer = function (short_id, definition)
    local texture = '([combine:16x16:-1,1=+s)^((+h^+m)^[makealpha:0,0,0)'
    texture = texture:gsub('+.', {
        ['+s'] = 'default_stick.png',
        ['+h'] = definition.head,
        ['+m'] = 'uniham_head_mask.png'
    })

    local on_use = definition.on_use or use_hammer

    minetest.register_tool('uniham:'..short_id, {
        description = definition.name,
        inventory_image = texture,
        _uniham = { uses = definition.uses },
        on_use = function(itemstack, player, pointed_thing)
            return on_use(itemstack, player, pointed_thing)
        end
    })

    minetest.register_craft({
        output = minetest.get_current_modname()..':'..short_id,
        recipe = {
            { '',            definition.craft,  ''               },
            { '',            'default:stick',   definition.craft },
            { 'default:stick', '',              ''               }
        }
    })
end