fantasy-brawl-cd2025/utils.lua

local function random_2dvectors() end
local last_pls_y_velocity = {} -- pl_name = y_velocity
local get_node = minetest.get_node
local get_pl_by_name = minetest.get_player_by_name



function fbrawl.replace_slot_item(player, slot, item) 
   local inv = player:get_inventory()
   local list = inv:get_list("main")
   list[slot] = ItemStack(item) 

   inv:set_list("main", list)
end



function fbrawl.hit_player(puncher, player, damage) 
   player:set_hp(player:get_hp() - damage, {
      type = "punch",
      object = puncher,
      from = "mod"
   })
end



function fbrawl.is_on_the_ground(player)
   local pl_name = player:get_player_name()
   local under_pl_feet = player:get_pos()
   local pl_velocity = player:get_velocity()
   local last_y_velocity = last_pls_y_velocity[pl_name] or pl_velocity.y

   under_pl_feet.y = under_pl_feet.y - 0.4
   
   local is_on_the_ground = 
      not (get_node(under_pl_feet).name == "air")
      or (pl_velocity.y == 0 and last_y_velocity < 0)
   
   last_pls_y_velocity[pl_name] = pl_velocity.y
   
   return is_on_the_ground
end



function fbrawl.area_raycast_up(center, radius, range, objects, liquids)
   local ray_distance = 0.5
   
   if type(radius) == "number" then
      radius_x = radius
      radius_z = radius
   else
      radius_x = radius.x
      radius_z = radius.z
   end
   
   local start_pos = {x = center.x - radius_x, y = center.y + 0.5, z = center.z - radius_z}
   local final_pos = {x = center.x + radius_x, y = center.y + 0.5, z = center.z + radius_z}
   
   for x = start_pos.x, final_pos.x, ray_distance do
      for z = start_pos.z, final_pos.z, ray_distance do
         local pos1 = {x = x, y = start_pos.y, z = z}
         local pos2 = vector.add(pos1, {x = 0, y = range, z = 0})
         local result = minetest.raycast(pos1, pos2, objects, liquids):next()
         
         if result then 
            return result 
         end
      end
   end

   return false
end



-- TODO: improve
function fbrawl.camera_shake(pl_name, duration, strength, offsets, next_offset, eye_offset, last)
   local player = get_pl_by_name(pl_name)
   local speed = 0.4
   local last = last or false
   offsets = offsets or random_2dvectors(duration, strength)
   next_offset = next_offset or 1

   if not player then
      return
   end
   
   -- When offsets finish go back to zero
   if next_offset > #offsets then
      offsets[next_offset] = {x = 0, y = 0}
      last = true
   end
   
   eye_offset = eye_offset or player:get_eye_offset()
   local target_offset = offsets[next_offset]
   local new_offset = {
      x = fbrawl.interpolate(eye_offset.x, target_offset.x, speed),
      y = fbrawl.interpolate(eye_offset.y, target_offset.y, speed),
      z = 0
   }
   eye_offset = new_offset

   -- If new_offset and eye_offset are equal go to the next offset or return if it was
   -- the last offset
   if target_offset.x == eye_offset.x and target_offset.y == eye_offset.y then
      if last then 
         return 
      end
      next_offset = next_offset + 1
   else
      player:set_eye_offset(new_offset, new_offset)
   end

   minetest.after(0, function() 
      fbrawl.camera_shake(pl_name, duration, strength, offsets, next_offset, eye_offset, last)
   end)
end



function fbrawl.reset_velocity(player)
   player:add_velocity(vector.multiply(player:get_velocity(), -1))
end



function fbrawl.interpolate(a, b, factor)
   local distance = math.abs(a-b)
   local min_step = 0.1
   local step = distance * factor
   if step < min_step then step = min_step end

   if a > b then
      a = a - step
      if a <= b then
         a = b
      end
   else
      a = a + step
      if a >= b then
         a = b
      end
   end

   return a
end



function random_2dvectors(amount, strength)
   local rnd = PcgRandom(os.time())
   local vectors = {}

   for i = 1, amount, 1 do
      local rnd_vector = {
         x = rnd:next(-1, 1) * strength,
         y = rnd:next(-1, 1) * strength, 
      }

      table.insert(vectors, rnd_vector)
   end

   return vectors
end