init.lua

   1 playerphysics = {}
   2
   3 local function calculate_attribute_product(player, attribute)
   4         local a = minetest.deserialize(player:get_meta():get_string("playerphysics:physics"))
   5         local product = 1
   6         if a == nil or a[attribute] == nil then
   7                 return product
   8         end
   9         local factors = a[attribute]
  10         if type(factors) == "table" then
  11                 for _, factor in pairs(factors) do
  12                         product = product * factor
  13                 end
  14         end
  15         return product
  16 end
  17
  18 function playerphysics.add_physics_factor(player, attribute, id, value)
  19         local meta = player:get_meta()
  20         local a = minetest.deserialize(meta:get_string("playerphysics:physics"))
  21         if a == nil then
  22                 a = { [attribute] = { [id] = value } }
  23         elseif a[attribute] == nil then
  24                 a[attribute] = { [id] = value }
  25         else
  26                 a[attribute][id] = value
  27         end
  28         meta:set_string("playerphysics:physics", minetest.serialize(a))
  29         local raw_value = calculate_attribute_product(player, attribute)
  30         player:set_physics_override({[attribute] = raw_value})
  31 end
  32
  33 function playerphysics.remove_physics_factor(player, attribute, id)
  34         local meta = player:get_meta()
  35         local a = minetest.deserialize(meta:get_string("playerphysics:physics"))
  36         if a == nil or a[attribute] == nil then
  37                 -- Nothing to remove
  38                 return
  39         else
  40                 a[attribute][id] = nil
  41         end
  42         meta:set_string("playerphysics:physics", minetest.serialize(a))
  43         local raw_value = calculate_attribute_product(player, attribute)
  44         player:set_physics_override({[attribute] = raw_value})
  45 end