merged https://github.com/kestral246/hangglider, changed a couple things

LICENSE.txt

@@ -1,6 +1,7 @@
 License for Code
 ----------------
 Copyright (C) 2018 Piezo_
+Copyright (C) 2018 kestral246
 Copyright (C) 2016 cd2 (cdqwertz) <cdqwertz@gmail.com>
 
 This program is free software; you can redistribute it and/or
@@ -23,6 +24,7 @@ License for Media
 
 Textures:
 	glider_inventory.png: CC-BY-SA 3.0 UNPORTED. Created by cd2 (cdqwertz)
+	glider_struts.png: CC-BY-SA 3.0, Piezo_.
 	Default wood and wool textures from minetest-game.
 
 Models and sounds: 

README.md

@@ -0,0 +1,38 @@
+Hang Glider Mod for Minetest
+----------------------------
+This is a fork of the minetest-hangglider mod by Piezo_ (orderofthefourthwall@gmail.com)
+
+Which is located at:
+    <https://notabug.org/Piezo_/minetest-hangglider>
+
+**This version is an experimental version that is not intended for general use.**
+
+It includes the following changes by David G (kestral246@gmail.com):
+
+- Give visual indication that hangglider is equiped.
+    - Display simple overlay with blurred struts when equiped.
+    - Issue: don't know how to disable overlay when using third person view.
+
+- Also unequip hangglider when landing on water.
+
+- Attempt to linearize parabolic flight path.
+    - Start gravity stronger, but gradually reduce it as descent velocity increases.
+    - Don't use airstopper when equipped from the ground (descent velocity is low).
+    - Slightly increase flight speed to 1.25.
+
+- Unequip/equip cycling mid-flight should not fly farther than continuous flight.
+    - When equipping mid-air (descent velocity higher), use airstopper but increase descent slope afterwards.
+    - Create airbreak flag so all equips mid-flight use faster descent.
+    - Reset airbreak flag only when land (canExist goes false).
+    - Issue: it wouldn't reset if land in water, use fly, and launch from air, before I added test for water,
+        - Not sure if there are other such cases.
+
+- Did another round of parameter tuning.
+    - Commented out hud debug display code with prefix "--debug:".
+
+- For Minetest 5.x the glider's set_attach point needs to be offset by 1 node.
+    - Provided alternate commented out version of this line that has the correct offset.
+
+- Discovered that sprint mod interferes with this mod's speed settings.
+    - It's likely that other mods that affect player_physics will have this same problem.
+    - May need to consider adding player_monoid support to this mod.

init.lua

@@ -1,5 +1,50 @@
-hangglider = {}
+-- Hangglider mod for Minetest
+-- Original code by Piezo_ (orderofthefourthwall@gmail.com)
+-- 2018-11-14
+
+-- Modifications by David G (kestral246@gmail.com)
+-- 2018-11-24
+-- For Minetest 5.x, glider's set_attach needs to be offset by 1 node
+--     Switch to alternate commented line below with correct offset.
+-- Additional tuning of parameters.
+-- Commented out debug hud display code, prefixed with "--debug:".
+
+-- 2018-11-22
+-- Give visual indication that hangglider is equiped.
+--     Display simple overlay with blurred struts when equiped.
+--     Issue: don't know how to disable overlay in third person view.
+-- Also Unequip hangglider when landing on water.
+-- Attempt to linearize parabolic flight path.
+--     Start gravity stronger, but gradually reduce it as descent velocity increases.
+--     Don't use airstopper when equipped from the ground (descent velocity is low).
+--     Slightly increase flight speed to 1.25.
+-- Unequip/equip cycling mid-flight should not fly farther than continuous flight.
+--     When equipping mid-air (descent velocity higher), use airstopper but increase descent slope afterwards.
+--     Create airbreak flag so all equips mid-flight use faster descent.
+--     Reset airbreak flag only when land (canExist goes false).
+--     Issue: it wouldn't reset if land in water, use fly, and launch from air, before I added test for water,
+--            not sure if there are other such cases.
+-- Temporarily add hud debug display to show descent velocity, gravity override, and airbreak flag.
+--     Still in process of tuning all the parameters.
+
+
+-- Modifications by Piezo_
+-- 2018-11-25
+-- hud overlay and debug can be enabled/disabled
+-- Added blender-rendered overlay for struts using the actual model.
+-- Reduced airbreak penalty severity
+-- gave glider limited durability.
+
+
+local HUD_Overlay = true --show glider struts as overlay on HUD
+local debug = false --show debug info in top-center of hud
+hangglider = {} --Make this global, so other mods can tell if hangglider exists.
 hangglider.use = {}
+if HUD_Overlay then
+hangglider.id = {}  -- hud id for displaying overlay with struts
+end
+if debug then  hangglider.debug = {} end -- hud id for debug data
+hangglider.airbreak = {}  -- true if falling fast when equip
 
 minetest.register_entity("hangglider:airstopper", { --A one-instant entity that catches the player and slows them down.
 	hp_max = 3,
@@ -31,19 +76,65 @@ minetest.register_entity("hangglider:glider", {
 			local player = self.object:get_attach("parent")
 			if player then
 				local pos = player:getpos()
-				if hangglider.use[player:get_player_name()] then
-					if minetest.registered_nodes[minetest.get_node(vector.new(pos.x, pos.y-0.5, pos.z)).name] then
-						if not minetest.registered_nodes[minetest.get_node(vector.new(pos.x, pos.y-0.5, pos.z)).name].walkable then
+				local pname = player:get_player_name()
+				if hangglider.use[pname] then
+					local mrn_name = minetest.registered_nodes[minetest.get_node(vector.new(pos.x, pos.y-0.5, pos.z)).name]
+					if mrn_name then
+						if not (mrn_name.walkable or (mrn_name.drowning and mrn_name.drowning == 1)) then
 							canExist = true
-							if player:get_player_velocity().y > -4.5 and player:get_physics_override().gravity < 0 then
-								player:set_physics_override({
-									gravity = 0.02,
-								})
-							elseif player:get_player_velocity().y < -5 and player:get_physics_override().gravity > 0 then
-								player:set_physics_override({
-									gravity = -0.02,
-								})
+							local vel = player:get_player_velocity()
+							local grav = player:get_physics_override().gravity
+							if debug then player:hud_change(hangglider.debug[pname].id, "text", vel.y..', '..grav..', '..tostring(hangglider.airbreak[pname])) end
+							-- If airbreaking used, increase the descent progression to not give
+							-- mid-flight unequip/equip cycles a distance advantage.
+							if hangglider.airbreak[pname] then
+								if vel.y <= -4.0 then
+									grav = -0.2 --Extreme measures are needed, as sometimes speed will get a bit out of control
+								elseif vel.y <= -2.0 then
+									grav = -0.02
+								elseif vel.y <= -1.75 then
+									grav = 0.00125  -- *1
+								elseif vel.y <= -1.5 then
+									grav = 0.0025  -- *2
+								elseif vel.y <= -1.25 then
+									grav = 0.005  -- *2
+								elseif vel.y <= -1 then
+									grav = 0.015  -- *3
+								elseif vel.y <= -0.75 then
+									grav = 0.04  -- *4
+								elseif vel.y <= -0.5 then
+									grav = 0.08  -- *4
+								elseif vel.y <= -0.25 then
+									grav = 0.12  -- *3
+								elseif vel.y <= 0 then
+									grav = 0.3  -- *3
+								else  -- vel.y > 0
+									grav = 0.75  -- *1.5
 								end
+							else  -- normal descent progression
+								if vel.y <= -4.0 then
+									grav = -0.2
+								elseif vel.y <= -2.0 then
+									grav = -0.02
+								elseif vel.y <= -1.5 then
+									grav = 0.00125
+								elseif vel.y <= -1.25 then
+									grav = 0.0025
+								elseif vel.y <= -1 then
+									grav = 0.005
+								elseif vel.y <= -0.75 then
+									grav = 0.01
+								elseif vel.y <= -0.5 then
+									grav = 0.02
+								elseif vel.y <= -0.25 then
+									grav = 0.04
+								elseif vel.y <= 0 then
+									grav = 0.1
+								else  -- vel.y > 0
+									grav = 0.5
+								end
+							end
+							player:set_physics_override({gravity = grav})
 						end
 					end
 				end
@@ -51,8 +142,13 @@ minetest.register_entity("hangglider:glider", {
 					player:set_physics_override({
 						gravity = 1,
 						jump = 1,
+						speed = 1,
 					})
-					hangglider.use[player:get_player_name()] = false
+					hangglider.use[pname] = false
+					if HUD_Overlay then
+					player:hud_change(hangglider.id[pname], "text", "blank.png")
+					end
+					hangglider.airbreak[pname] = false
 				end
 			end
 		end
@@ -73,42 +169,84 @@ end)
 
 
 minetest.register_on_joinplayer(function(player)
+	local pname = player:get_player_name()
 	player:set_physics_override({
 		gravity = 1,
 		jump = 1,
 	})
-	hangglider.use[player:get_player_name()] = false
+	hangglider.use[pname] = false
+	if HUD_Overlay then
+	hangglider.id[pname] = player:hud_add({
+		hud_elem_type = "image",
+		text = "blank.png",
+		position = {x=0, y=0},
+		scale = {x=-100, y=-100},
+		alignment = {x=1, y=1},
+		offset = {x=0, y=0}
+	}) end
+	if debug then 
+		hangglider.debug[pname] = {id = player:hud_add({hud_elem_type = "text",
+			position = {x=0.5, y=0.1},
+			text = "-",
+			number = 0xFF0000}),  -- red text
+			-- ht = {50,50,50},
+		}
+	end
+	hangglider.airbreak[pname] = false
 end)
 
 minetest.register_on_leaveplayer(function(player)
-	hangglider.use[player:get_player_name()] = nil
+	local pname = player:get_player_name()
+	hangglider.use[pname] = nil
+	if HUD_Overlay then hangglider.id[pname] = nil end
+	if debug then hangglider.debug[pname] = nil end
+	hangglider.airbreak[pname] = nil
 end)
 
-minetest.register_craftitem("hangglider:hangglider", {
+minetest.register_tool("hangglider:hangglider", {
 	description = "Glider",
 	inventory_image = "glider_item.png",
-	
+	stack_max=1,
 	on_use = function(itemstack, user, pointed_thing)
 		if not user then
 			return
 		end
 		local pos = user:get_pos()
-		if minetest.get_node(pos).name == "air" and not hangglider.use[user:get_player_name()] then --Equip
+		local pname = user:get_player_name()
+		if minetest.get_node(pos).name == "air" and not hangglider.use[pname] then --Equip
 			minetest.sound_play("bedsheet", {pos=pos, max_hear_distance = 8, gain = 1.0})
+			if HUD_Overlay then user:hud_change(hangglider.id[pname], "text", "glider_struts.png") end
+			local vel = user:get_player_velocity().y
+			if vel < -2 then  -- engage mid-air, falling fast, so stop but ramp velocity more quickly
+				hangglider.airbreak[pname] = true
 				user:set_physics_override({
-				gravity = 0.02,
+					gravity = 1,
 					jump = 0,
+					speed = 1.75,
 				})
 				local stopper = minetest.add_entity(pos, "hangglider:airstopper")
 				stopper:get_luaentity().attach = user
 				user:set_attach( stopper, "", {x=0,y=0,z=0}, {x=0,y=0,z=0})
-			hangglider.use[user:get_player_name()] = true
+			else
+				user:set_physics_override({
+					gravity = 0.02,
+					jump = 0,
+					speed = 1.75,
+				})
+			end
+			hangglider.use[pname] = true
+			-- if minetest 0.4.x use this:
 			minetest.add_entity(user:get_pos(), "hangglider:glider"):set_attach(user, "", {x=0,y=0,z=0}, {x=0,y=0,z=0})
-			
-		elseif hangglider.use[user:get_player_name()] then --Unequip
-			hangglider.use[user:get_player_name()] = false
-		end
+			-- if minetest 5.x use this:
+			-- minetest.add_entity(user:get_pos(), "hangglider:glider"):set_attach(user, "", {x=0,y=10,z=0}, {x=0,y=0,z=0})
+			itemstack:set_wear(itemstack:get_wear() + 255)
+			return itemstack
+		elseif hangglider.use[pname] then --Unequip
+			if HUD_Overlay then user:hud_change(hangglider.id[pname], "text", "blank.png") end
+			hangglider.use[pname] = false
 		end
+	end,
+	sound = {breaks = "default_tool_breaks"},
 })
 
 minetest.register_craft({