mods/ENTITIES/mcl_item_entity/init.lua

@@ -27,6 +27,11 @@ local mcl_item_entity = {}
 local item_drop_settings                 = {} --settings table
 item_drop_settings.dug_buffer            = 0.65 -- the warm up period before a dug item can be collected
 item_drop_settings.age                   = 1.0 --how old a dropped item (_insta_collect==false) has to be before collecting
+item_drop_settings.fluid_flow_rate       = 1.39 --the speed of a flowing fluid, used when computing push and drag forces of water on items; default is tuned to Minecraft
+item_drop_settings.fluid_drag            = 1.8 --how much drag water has on items (how quickly an item's motion will settle onto the water's flow speed)
+item_drop_settings.ground_drag           = 3.0 --how much friction with the ground slows items sliding on it
+item_drop_settings.slippery_drag_factor  = 0.25 --scales item friction with the ground on slippery floors (e.g. ice)
+item_drop_settings.slippery_fluid_drag_factor = 0.4 --scales item drag with waterflow on slippery floors (e.g. ice)
 item_drop_settings.radius_magnet         = 2.0 --radius of item magnet. MUST BE LARGER THAN radius_collect!
 item_drop_settings.xp_radius_magnet      = 7.25 --radius of xp magnet. MUST BE LARGER THAN radius_collect!
 item_drop_settings.radius_collect        = 0.2 --radius of collection
@@ -778,11 +783,35 @@ minetest.register_entity(":__builtin:item", {
 			-- Just to make sure we don't manipulate the speed for no reason
 			if vec.x ~= 0 or vec.y ~= 0 or vec.z ~= 0 then
 				-- Minecraft Wiki: Flowing speed is "about 1.39 meters per second"
-				local f = 1.39
-				-- Set new item moving speed into the direciton of the liquid
+				local f = item_drop_settings.fluid_flow_rate --1.39
+
+				-- Apply the force of the flowing liquid onto the item's velocity
 				local newv = vector.multiply(vec, f) 
 				self.object:set_acceleration({x = 0, y = 0, z = 0})
-				self.object:set_velocity({x = newv.x, y = -0.22, z = newv.z})
+
+				local oldvel = self.object:get_velocity() -- v is vector, vel is velocity
+
+				-- drag
+				local fluid_drag = item_drop_settings.fluid_drag
+
+                local floornn = minetest.get_node({x=p.x, y=p.y-0.5, z=p.z}).name
+                local floornode = floornn and minetest.registered_nodes[floornn]
+				if floornode and minetest.get_item_group(floornode.name, "slippery") then
+				    -- scale fluid drag on slippery floors
+				    fluid_drag = fluid_drag * item_drop_settings.slippery_fluid_drag_factor
+				end
+
+                newv.x = newv.x - (oldvel.x - newv.x) * fluid_drag * dtime
+                newv.y = newv.y - (oldvel.y - newv.y) * fluid_drag * dtime
+                newv.z = newv.z - (oldvel.z - newv.z) * fluid_drag * dtime
+
+                newv.y = newv.y + -0.22 -- (keep slight downward thrust from previous version of code)
+                                        -- NOTE:    is there any particular reason we have this, anyway?
+                                        --          since fluid drag is now on, we could as well just
+                                        --          apply gravity here; drag will slow down the fall
+                                        --          realistically
+				
+				self.object:set_velocity({x = oldvel.x + newv.x * dtime, y = oldvel.y + newv.y * dtime, z = oldvel.z + newv.z * dtime})
 
 				self.physical_state = true
 				self._flowing = true
@@ -794,15 +823,17 @@ minetest.register_entity(":__builtin:item", {
 		elseif self._flowing == true then
 			-- Disable flowing physics if not on/in flowing liquid
 			self._flowing = false
-			enable_physics(self.object, self, true)
+			--enable_physics(self.object, self, true) -- do not reset velocity upon leaving water!
+			self.object:set_acceleration({x=0,y=-get_gravity(),z=0}) -- resume applying gravity
 			return
 		end
 
 		-- If node is not registered or node is walkably solid and resting on nodebox
 		local nn = minetest.get_node({x=p.x, y=p.y-0.5, z=p.z}).name
 		local v = self.object:get_velocity()
+		local node = nn and minetest.registered_nodes[nn]
 
-		if not minetest.registered_nodes[nn] or minetest.registered_nodes[nn].walkable and v.y == 0 then
+		if not node or node.walkable and v.y == 0 then
 			if self.physical_state then
 				local own_stack = ItemStack(self.object:get_luaentity().itemstring)
 				-- Merge with close entities of the same item
@@ -815,7 +846,28 @@ minetest.register_entity(":__builtin:item", {
 						end
 					end
 				end
+				--disable_physics(self.object, self)
+				-- apply ground drag
+				local oldvel = self.object:get_velocity()
+
+                -- ignore momentum if it's tiny
+				if math.abs(oldvel.x) < 0.05 and math.abs(oldvel.z) < 0.05 then
 				    disable_physics(self.object, self)
+				    return
+                end
+
+                local ground_drag = item_drop_settings.ground_drag
+
+                if node and minetest.get_item_group(node.name, "slippery") ~= 0 then
+                    ground_drag = ground_drag * item_drop_settings.slippery_drag_factor
+                end
+                
+				local newvel = {
+				    x = oldvel.x - oldvel.x * ground_drag * dtime,
+				    y = 0,
+				    z = oldvel.z - oldvel.z * ground_drag * dtime
+                }
+                self.object:set_velocity(newvel)
 			end
 		else
 			if self._magnet_active == false then

mods/ITEMS/REDSTONE/mcl_dispensers/init.lua

@@ -260,9 +260,22 @@ local dispenserdef = {
 							end
 						else
 							-- Drop item otherwise
-							minetest.add_item(droppos, dropitem)
+							-- Drop item normally
+            				local dropitemobj = minetest.add_item(droppos, dropitem)
             				stack:take_item()
             				inv:set_stack("main", stack_id, stack)
+
+            				-- Set item velocity (overrides the default random drop direction)
+            				local shoot_force = 1.3
+
+            				local newv = minetest.facedir_to_dir(node.param2)
+            				newv = {
+            				    x = newv.x * shoot_force,
+            				    y = newv.y * shoot_force,
+            				    z = newv.z * shoot_force
+            				}
+
+            				dropitemobj:set_velocity(newv)
 						end
 					end
 

mods/ITEMS/REDSTONE/mcl_droppers/init.lua

@@ -134,9 +134,21 @@ local dropperdef = {
 				-- No container?
 				if not dropped and not dropnodedef.groups.container then
 					-- Drop item normally
-					minetest.add_item(droppos, dropitem)
+					local dropitemobj = minetest.add_item(droppos, dropitem)
 					stack:take_item()
 					inv:set_stack("main", stack_id, stack)
+
+					-- Set item velocity (overrides the default random drop direction)
+					local shoot_force = 1.3
+
+					local newv = minetest.facedir_to_dir(node.param2)
+					newv = {
+					    x = -newv.x * shoot_force,
+					    y = -newv.y * shoot_force,
+					    z = -newv.z * shoot_force
+					}
+
+					dropitemobj:set_velocity(newv)
 				end
 			end
 		end,