From 1749712318b0b71969cb77921e13de21780c882f Mon Sep 17 00:00:00 2001
From: ancientmarinerdev <ancientmariner_dev@proton.me>
Date: Thu, 31 Aug 2023 23:12:30 +0100
Subject: [PATCH] Change creepers line of sight check to raycast and do it from
 eyes to targets feet and head

---
 mods/ENTITIES/mcl_mobs/combat.lua   |  3 +-
 mods/ENTITIES/mcl_mobs/movement.lua | 76 +++++++++++++++++++++++++++++
 mods/ENTITIES/mobs_mc/creeper.lua   |  1 +
 3 files changed, 79 insertions(+), 1 deletion(-)

diff --git a/mods/ENTITIES/mcl_mobs/combat.lua b/mods/ENTITIES/mcl_mobs/combat.lua
index 836f53753..4b3393e36 100644
--- a/mods/ENTITIES/mcl_mobs/combat.lua
+++ b/mods/ENTITIES/mcl_mobs/combat.lua
@@ -853,7 +853,8 @@ function mob_class:do_states_attack (dtime)
 		return
 	end
 
-	local target_line_of_sight = self:line_of_sight(s, p, 2)
+	local target_line_of_sight = self:target_visible(s)
+
 	if not target_line_of_sight then
 		if self.target_time_lost then
 			local time_since_seen = os.time() - self.target_time_lost
diff --git a/mods/ENTITIES/mcl_mobs/movement.lua b/mods/ENTITIES/mcl_mobs/movement.lua
index 317ac9f28..46c470a15 100644
--- a/mods/ENTITIES/mcl_mobs/movement.lua
+++ b/mods/ENTITIES/mcl_mobs/movement.lua
@@ -76,6 +76,82 @@ function mob_class:is_node_waterhazard(nodename)
 	return false
 end
 
+
+local function raycast_line_of_sight (origin, target)
+	local raycast = minetest.raycast(origin, target, false, true)
+
+	local los_blocked = false
+
+	for hitpoint in raycast do
+		if hitpoint.type == "node" then
+			--TODO type object could block vision, for example chests
+			--minetest.log(dump(hitpoint.type))
+
+			local node = minetest.get_node(minetest.get_pointed_thing_position(hitpoint))
+
+			--minetest.log("ray node:" .. node.name)
+
+			if node.name ~= "air" then
+				local nodef = minetest.registered_nodes[node.name]
+				if nodef and nodef.walkable then
+					--minetest.log("walkable:" .. tostring(nodef.walkable))
+					los_blocked = true
+					break
+				end
+			end
+		end
+	end
+	--minetest.log("los_blocked: " .. tostring(los_blocked))
+	--minetest.log("visible: " .. tostring(not los_blocked))
+
+	return not los_blocked
+end
+
+function mob_class:target_visible(origin)
+	if not origin then return end
+
+	if not self.attack then return end
+	local target_pos = self.attack:get_pos()
+
+	if not target_pos then return end
+
+	local origin_eye_pos = vector.offset(origin, 0, self.head_eye_height, 0)
+
+	--minetest.log("origin: " .. dump(origin))
+	--minetest.log("origin_eye_pos: " .. dump(origin_eye_pos))
+
+	local targ_head_height, targ_feet_height
+	if self.attack:is_player() then
+		local cbox = self.object:get_properties().collisionbox
+		targ_head_height = vector.offset(target_pos, 0, cbox[5], 0)
+		targ_feet_height = target_pos -- Cbox would put feet under ground which interferes with ray
+	else
+		targ_head_height = vector.offset(target_pos, 0, self.collisionbox[5], 0)
+		targ_feet_height = vector.offset(target_pos, 0, self.collisionbox[2], 0)
+	end
+
+	--local target_line_of_sight = self:line_of_sight(origin_eye_pos, targ_head_height, 2)
+	--local target_line_of_sight_feet = self:line_of_sight(origin_eye_pos, targ_feet_height, 2)
+
+	--minetest.log("target_line_of_sight: " .. tostring(target_line_of_sight))
+	--minetest.log("target_line_of_sight_feet: " .. tostring(target_line_of_sight_feet))
+
+	--minetest.log("start targ_head_height: " .. dump(targ_head_height))
+	if raycast_line_of_sight (origin_eye_pos, targ_head_height) then
+		return true
+	end
+
+	--minetest.log("Start targ_feet_height: " .. dump(targ_feet_height))
+	if raycast_line_of_sight (origin_eye_pos, targ_feet_height) then
+		return true
+	end
+
+	-- TODO mid way between feet and head
+
+	--minetest.log("target is not visible so return false")
+	return false
+end
+
 -- check line of sight (BrunoMine)
 function mob_class:line_of_sight(pos1, pos2, stepsize)
 
diff --git a/mods/ENTITIES/mobs_mc/creeper.lua b/mods/ENTITIES/mobs_mc/creeper.lua
index f751b1240..72661971e 100644
--- a/mods/ENTITIES/mobs_mc/creeper.lua
+++ b/mods/ENTITIES/mobs_mc/creeper.lua
@@ -24,6 +24,7 @@ mcl_mobs.register_mob("mobs_mc:creeper", {
 	mesh = "mobs_mc_creeper.b3d",
 	head_swivel = "Head_Control",
 	bone_eye_height = 2.35,
+	head_eye_height = 1.8;
 	curiosity = 2,
 	textures = {
 		{"mobs_mc_creeper.png",