From 830b1698ffa75c16345096b20a2b52e0276d2e5d Mon Sep 17 00:00:00 2001
From: TenPlus1 <kinsellaja@yahoo.com>
Date: Fri, 14 Sep 2018 17:13:40 +0100
Subject: [PATCH] added pushable flag for mobs so they can be pushed by player

---
 api.lua | 43 ++++++++++++++++++++++++++++++++++++++++---
 api.txt |  1 +
 2 files changed, 41 insertions(+), 3 deletions(-)

diff --git a/api.lua b/api.lua
index 79b178d..17b3b11 100644
--- a/api.lua
+++ b/api.lua
@@ -6,7 +6,7 @@ local use_cmi = minetest.global_exists("cmi")
 
 mobs = {
 	mod = "redo",
-	version = "20180909",
+	version = "20180914",
 	intllib = S,
 	invis = minetest.global_exists("invisibility") and invisibility or {},
 }
@@ -108,9 +108,45 @@ local do_attack = function(self, player)
 end
 
 
+-- collision function borrowed amended from jordan4ibanez open_ai mod
+local collision = function(self)
+
+	local pos = self.object:get_pos()
+	local vel = self.object:get_velocity()
+	local x = 0
+	local z = 0
+	local width = -self.collisionbox[1] + self.collisionbox[4] + 0.5
+
+	for _,object in ipairs(minetest.env:get_objects_inside_radius(pos, width)) do
+
+		if object:is_player()
+		or (object:get_luaentity()._cmi_is_mob == true and object ~= self.object) then
+
+			local pos2 = object:get_pos()
+			local vec  = {x = pos.x - pos2.x, z = pos.z - pos2.z}
+			local force = (width + 0.5) - vector.distance(
+				{x = pos.x, y = 0, z = pos.z},
+				{x = pos2.x, y = 0, z = pos2.z})
+
+			x = x + (vec.x * force)
+			z = z + (vec.z * force)
+		end
+	end
+
+	return({x,z})
+end
+
+
 -- move mob in facing direction
 local set_velocity = function(self, v)
 
+	local c_x, c_y = 0, 0
+
+	-- can mob be pushed, if so calculate direction
+	if self.pushable then
+		c_x, c_y = unpack(collision(self))
+	end
+
 	-- halt mob if it has been ordered to stay
 	if self.order == "stand" then
 		self.object:set_velocity({x = 0, y = 0, z = 0})
@@ -120,9 +156,9 @@ local set_velocity = function(self, v)
 	local yaw = (self.object:get_yaw() or 0) + self.rotate
 
 	self.object:set_velocity({
-		x = sin(yaw) * -v,
+		x = (sin(yaw) * -v) + c_x,
 		y = self.object:get_velocity().y,
-		z = cos(yaw) * v
+		z = (cos(yaw) * v) + c_y,
 	})
 end
 
@@ -3049,6 +3085,7 @@ minetest.register_entity(name, {
 	runaway_from = def.runaway_from,
 	owner_loyal = def.owner_loyal,
 	facing_fence = false,
+	pushable = def.pushable,
 	_cmi_is_mob = true,
 
 	on_spawn = def.on_spawn,
diff --git a/api.txt b/api.txt
index 8e3fdd0..126de42 100644
--- a/api.txt
+++ b/api.txt
@@ -45,6 +45,7 @@ functions needed for the mob to work properly which contains the following:
    'fly_in'        holds the node name that the mob flies (or swims) around
                    in e.g. "air" or "default:water_source".
    'runaway'       if true causes animals to turn and run away when hit.
+   'pushable'      when true mobs can be pushed by player or other mobs.
    'view_range'    how many nodes in distance the mob can see a player.
    'damage'        how many health points the mob does to a player or another
                    mob when melee attacking.