1 -- can be overriden by mods
2 function core.calculate_knockback(player, hitter, time_from_last_punch, tool_capabilities, dir, distance, damage)
3 if damage == 0 or player:get_armor_groups().immortal then
8 -- solve m - m*e^(k*4) = 4 for k
10 local res = m - m * math.exp(k * damage)
12 if distance < 2.0 then
13 res = res * 1.1 -- more knockback when closer
14 elseif distance > 4.0 then
15 res = res * 0.9 -- less when far away
20 local function vector_absmax(v)
21 local max, abs = math.max, math.abs
22 return max(max(abs(v.x), abs(v.y)), abs(v.z))
25 core.register_on_punchplayer(function(player, hitter, time_from_last_punch, tool_capabilities, unused_dir, damage)
26 if player:get_hp() == 0 then
30 -- Server::handleCommand_Interact() adds eye offset to one but not the other
31 -- so the direction is slightly off, calculate it ourselves
32 local dir = vector.subtract(player:get_pos(), hitter:get_pos())
33 local d = vector.length(dir)
35 dir = vector.divide(dir, d)
38 local k = core.calculate_knockback(player, hitter, time_from_last_punch, tool_capabilities, dir, d, damage)
40 local kdir = vector.multiply(dir, k)
41 if vector_absmax(kdir) < 1.0 then
42 return -- barely noticeable, so don't even send
45 player:add_player_velocity(kdir)