From 45ec87616705a596ea67c7f9af8d7a4b47cbb9be Mon Sep 17 00:00:00 2001
From: MysticTempest <molecularmarc.he@gmail.com>
Date: Tue, 7 Jun 2022 02:55:19 -0500
Subject: [PATCH] Knockback fixes:

This PR enables knockback for snowballs, and eggs.
And disables knockback for the following mobs: Shulkers, Iron Golems,
and Ender Dragons.
---
 mods/ENTITIES/mcl_mobs/api.lua         | 51 +++++++++++++-------------
 mods/ENTITIES/mobs_mc/ender_dragon.lua |  1 +
 mods/ENTITIES/mobs_mc/iron_golem.lua   |  1 +
 mods/ENTITIES/mobs_mc/shulker.lua      |  1 +
 mods/ITEMS/mcl_throwing/register.lua   |  4 +-
 5 files changed, 30 insertions(+), 28 deletions(-)

diff --git a/mods/ENTITIES/mcl_mobs/api.lua b/mods/ENTITIES/mcl_mobs/api.lua
index 933634cce..577c4c2aa 100644
--- a/mods/ENTITIES/mcl_mobs/api.lua
+++ b/mods/ENTITIES/mcl_mobs/api.lua
@@ -3210,35 +3210,36 @@ local mob_punch = function(self, hitter, tflp, tool_capabilities, dir)
 
 	local die = false
 
-	-- only play hit sound and show blood effects if damage is 1 or over; lower to 0.1 to ensure armor works appropriately.
-	if damage >= 0.1 then
 
-		-- weapon sounds
-		if weapon:get_definition().sounds ~= nil then
+	if damage >= 0 then
+		-- only play hit sound and show blood effects if damage is 1 or over; lower to 0.1 to ensure armor works appropriately.
+		if damage >= 0.1 then
+			-- weapon sounds
+			if weapon:get_definition().sounds ~= nil then
 
-			local s = random(0, #weapon:get_definition().sounds)
+				local s = random(0, #weapon:get_definition().sounds)
 
-			minetest.sound_play(weapon:get_definition().sounds[s], {
-				object = self.object, --hitter,
-				max_hear_distance = 8
-			}, true)
-		else
-			minetest.sound_play("default_punch", {
-				object = self.object,
-				max_hear_distance = 5
-			}, true)
+				minetest.sound_play(weapon:get_definition().sounds[s], {
+					object = self.object, --hitter,
+					max_hear_distance = 8
+				}, true)
+			else
+				minetest.sound_play("default_punch", {
+					object = self.object,
+					max_hear_distance = 5
+				}, true)
+			end
+
+			damage_effect(self, damage)
+
+			-- do damage
+			self.health = self.health - damage
+
+			-- skip future functions if dead, except alerting others
+			if check_for_death(self, "hit", {type = "punch", puncher = hitter}) then
+				die = true
+			end
 		end
-
-		damage_effect(self, damage)
-
-		-- do damage
-		self.health = self.health - damage
-
-		-- skip future functions if dead, except alerting others
-		if check_for_death(self, "hit", {type = "punch", puncher = hitter}) then
-			die = true
-		end
-
 		-- knock back effect (only on full punch)
 		if not die
 		and self.knock_back
diff --git a/mods/ENTITIES/mobs_mc/ender_dragon.lua b/mods/ENTITIES/mobs_mc/ender_dragon.lua
index d2f971f79..e7a233fc5 100644
--- a/mods/ENTITIES/mobs_mc/ender_dragon.lua
+++ b/mods/ENTITIES/mobs_mc/ender_dragon.lua
@@ -35,6 +35,7 @@ mcl_mobs:register_mob("mobs_mc:enderdragon", {
 	},
 	physical = true,
 	damage = 10,
+	knock_back = false,
 	jump = true,
 	jump_height = 14,
 	fly = true,
diff --git a/mods/ENTITIES/mobs_mc/iron_golem.lua b/mods/ENTITIES/mobs_mc/iron_golem.lua
index 7f1e66714..81c7ed4bb 100644
--- a/mods/ENTITIES/mobs_mc/iron_golem.lua
+++ b/mods/ENTITIES/mobs_mc/iron_golem.lua
@@ -37,6 +37,7 @@ mcl_mobs:register_mob("mobs_mc:iron_golem", {
 	run_velocity = 1.2,
 	-- Approximation
 	damage = 14,
+	knock_back = false,
 	reach = 3,
 	group_attack = true,
 	attacks_monsters = true,
diff --git a/mods/ENTITIES/mobs_mc/shulker.lua b/mods/ENTITIES/mobs_mc/shulker.lua
index 5b3c4d282..77273db2f 100644
--- a/mods/ENTITIES/mobs_mc/shulker.lua
+++ b/mods/ENTITIES/mobs_mc/shulker.lua
@@ -33,6 +33,7 @@ mcl_mobs:register_mob("mobs_mc:shulker", {
 	-- TODO: Make shulker dye-able
 	visual_size = {x=3, y=3},
 	walk_chance = 0,
+	knock_back = false,
 	jump = false,
 	drops = {
 		{name = "mcl_mobitems:shulker_shell",
diff --git a/mods/ITEMS/mcl_throwing/register.lua b/mods/ITEMS/mcl_throwing/register.lua
index 413bc9d5f..53af28652 100644
--- a/mods/ITEMS/mcl_throwing/register.lua
+++ b/mods/ITEMS/mcl_throwing/register.lua
@@ -61,11 +61,9 @@ local function check_object_hit(self, pos, dmg)
 		and entity.name ~= self.object:get_luaentity().name then
 
 			if object:is_player() and self._thrower ~= object:get_player_name() then
-				-- TODO: Deal knockback
 				self.object:remove()
 				return true
 			elseif (entity.is_mob == true or entity._hittable_by_projectile) and (self._thrower ~= object) then
-				-- FIXME: Knockback is broken
 				object:punch(self.object, 1.0, {
 					full_punch_interval = 1.0,
 					damage_groups = dmg,
@@ -185,7 +183,7 @@ local function egg_on_step(self, dtime)
 	end
 
 	-- Destroy when hitting a mob or player (no chick spawning)
-	if check_object_hit(self, pos) then
+	if check_object_hit(self, pos, 0) then
 		minetest.sound_play("mcl_throwing_egg_impact", { pos = self.object:get_pos(), max_hear_distance=10, gain=0.5 }, true)
 		self.object:remove()
 		return