Add 'display_api/' from commit '3a43e4ad81dc6595fabfa22c88e229c393f93529'

git-subtree-dir: display_api
git-subtree-mainline: 135cae721906d312cd0084f7343a15760e3aa722
git-subtree-split: 3a43e4ad81dc6595fabfa22c88e229c393f93529

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diff --git a/display_api/API.md b/display_api/API.md
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--- /dev/null
+++ b/display_api/API.md
@@ -0,0 +1,92 @@
+# Display API
+This document describes Display API. Display API allows to add a dynamic display on a node. Display API limits node rotations. For wallmounted, only vertical positionning is available. For facedir, only first four position are availabel (those with default axis).
+
+## Provided methods
+### update\_entities
+**display\_api.update\_entities(pos)**
+
+This method triggers entities update for the display node at pos. Actual entity update is made by `on_display_update` callback associated to the entity.
+
+`pos`: Position of the node
+### register\_display\_entity
+**display\_api.register\_display\_entity(entity_name)**
+
+This is a helper to register entities used for display.
+
+`entity_name`: Name of the entity to register.
+
+## Provided callback implementations
+### on_place
+**display\_api.on\_place(itemstack, placer, pointed\_thing)**
+
+`on_place` node callback implementation. Display nodes should have this callback (avoid placement of horizontal display node).
+### on_construct
+**display\_api.on\_construct(pos)**
+
+`on_construct` node callback implementation. Display nodes should have this callback (creates, places and updates display entities on node construction).
+### on_destruct
+**display\_api.on_destruct(pos)**
+
+`on_destruct` node callback implementation. Display nodes should have this callback (removes display entities on node destruction).
+### on_rotate
+**display\_api.on\_rotate(pos, node, user, mode, new_param2)**
+
+`on_rotate` node callback implementation. Display nodes should have this callback (restricts rotations and rotates display entities associated with node).
+### on_activate
+**display\_api.on_activate(entity, staticdata)**
+
+`On_activate` entity callback implementation for display entities. No need of this method if display entities have been registered using `register_display_entity` (callback is already set).
+
+## Howto register a display node
+* Register display entities with `register_display_entity`
+
+* Register node with :
+  - `on_place`, `on_construct`, `on_destruct` and `on_rotate` callbacks using display_api callbacks.\
+  - `display_api` group. This will make this node have their entities updated as soon as the mapblock is loaded (Useful after /clearobjects).\
+  - a `display_entities` field in node definition containing a entity name indexed table. See below for description of each display_entities fields.\
+
+### Display_entities fields
+`on_display_update` is a callback in charge of setting up entity texture. If not set, entity will have no texture and will be displayed as unknown item.\
+`depth`, `right` and `top`: Entity position regarding to node facedir/wallmounted main axis.\
+Values for these fields can be any number between -1.5 and 1.5 (default value is 0). Position 0,0,0 is the center of the node.\
+`depth` goes from front (-0.5) to rear (0.5), `top` goes from bottom (-0.5) to top (0.5) and `right` goes from left (-0.5) to right (0.5).\
+`yaw`: Entity yaw in radians, regarding to main axis. Default is 0, aligned to node face.
+
+In order to avoid flickering text, it's better to have text a little behind node surface. A good spacing value is given by `display_api.entity_spacing` variable.
+
+### Example
+
+	display_api.register_display_entity("mymod:entity1")
+	display_api.register_display_entity("mymod:entity2")
+
+	function my_display_update1(pos, objref)
+		objref:set_properties({ textures= {"mytexture1.png"},
+		                        visual_size = {x=1, y=1} })
+	end
+
+	function my_display_update2(pos, objref)
+		objref:set_properties({ textures= {"mytexture2.png"},
+		                        visual_size = {x=1, y=1} })
+	end
+
+	minetest.register_node("mymod:test_display_node", {
+		...
+		paramtype2 = "facedir",
+		...
+		groups = { display_api = 1, ... },
+		...
+		display_entities = {
+			["mymod:entity1"] = {
+				depth = 0.3,
+				on_display_update = my_display_update1 },
+			["mymod:entity1"] = {
+				depth = 0.2, top = 0.1,
+				on_display_update = my_display_update2 },
+			},
+		...
+		on_place = display_api.on_place,
+		on_construct = display_api.on_construct,
+		on_destruct = display_api.on_destruct,
+		on_rotate = display_api.on_rotate,
+		...
+	})
diff --git a/display_api/LICENSE.txt b/display_api/LICENSE.txt
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index 0000000..341c30b
--- /dev/null
+++ b/display_api/LICENSE.txt
@@ -0,0 +1,166 @@
+                   GNU LESSER GENERAL PUBLIC LICENSE
+                       Version 3, 29 June 2007
+
+ Copyright (C) 2007 Free Software Foundation, Inc. <http://fsf.org/>
+ Everyone is permitted to copy and distribute verbatim copies
+ of this license document, but changing it is not allowed.
+
+
+  This version of the GNU Lesser General Public License incorporates
+the terms and conditions of version 3 of the GNU General Public
+License, supplemented by the additional permissions listed below.
+
+  0. Additional Definitions.
+
+  As used herein, "this License" refers to version 3 of the GNU Lesser
+General Public License, and the "GNU GPL" refers to version 3 of the GNU
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diff --git a/display_api/README.md b/display_api/README.md
new file mode 100644
index 0000000..73acdf9
--- /dev/null
+++ b/display_api/README.md
@@ -0,0 +1,34 @@
+# Display API
+
+This library's purpose is to ease creation of nodes with one or more displays on sides. For example, signs and clocks. Display can be dynamic and/or different for each node instance.
+
+**Limitations**: This lib uses entities to draw display. This means display has to be vertical (and "upside up") on Minetest before version 5.0.
+
+**Dependancies**:default
+
+**License**: LGPLv2
+
+**API**: See [API.md](https://github.com/pyrollo/display_modpack/blob/master/display_api/API.md) document please.
+
+For more information, see the [forum topic](https://forum.minetest.net/viewtopic.php?t=19365) at the Minetest forums.
+
+## Deprecation notice (for modders)
+
+### December 2018
+Following objects are deprecated, shows a warning in log when used:
+* `display_modpack_node` group (use `display_api` group instead);
+* `display_lib_node` group (use `display_api` group instead);
+* `display_lib` global table (use `display_api` global table instead);
+
+These objects will be removed in the future.
+
+## Change log
+### 2019-03-14
+- __dispay_api__: Display API now detects automatically whenr rotation restrictions have to be applied.
+
+### 2019-03-09
+- __display_api__: Display nodes can be rotated in every directions (if running Minetest 5 or above).
+- __display_api__: New setting to restrict rotations to Minetest 0.4 abilities (restriction enabled by default).
+
+### 2018-12-14
+- __display_api__: New `yaw` attributes, entities can now have different angles with node.
diff --git a/display_api/copyright.txt b/display_api/copyright.txt
new file mode 100644
index 0000000..e242c7c
--- /dev/null
+++ b/display_api/copyright.txt
@@ -0,0 +1,5 @@
+Code by Pierre-Yves Rollo (pyrollo)
+Contributors:
+(gpcf): Compatibility with signs lib
+(Thomas--S): Fix /clearobjects bug
+(12Me21): on_place and on_rotate improvements
diff --git a/display_api/depends.txt b/display_api/depends.txt
new file mode 100644
index 0000000..e69de29
--- /dev/null
+++ b/display_api/depends.txt
diff --git a/display_api/deprecation.lua b/display_api/deprecation.lua
new file mode 100644
index 0000000..b041f6f
--- /dev/null
+++ b/display_api/deprecation.lua
@@ -0,0 +1,78 @@
+--[[
+		display_api mod for Minetest - Library to add dynamic display
+		capabilities to nodes
+		(c) Pierre-Yves Rollo
+
+		This program is free software: you can redistribute it and/or modify
+		it under the terms of the GNU General Public License as published by
+		the Free Software Foundation, either version 3 of the License, or
+		(at your option) any later version.
+
+		This program is distributed in the hope that it will be useful,
+		but WITHOUT ANY WARRANTY; without even the implied warranty of
+		MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+		GNU General Public License for more details.
+
+		You should have received a copy of the GNU General Public License
+		along with this program.  If not, see <http://www.gnu.org/licenses/>.
+--]]
+
+-- Deprecation
+
+function deprecated_group(deprecated_group, replacement_group)
+	for name, ndef in pairs(minetest.registered_nodes) do
+		if ndef.groups and ndef.groups[deprecated_group] then
+			minetest.log("warning", string.format(
+				'Node %s belongs to deprecated "%s" group which should be replaced with new "%s" group.',
+				name, deprecated_group, replacement_group))
+		end
+	end
+end
+
+function deprecated_global_table(deprecated_global_name, replacement_global_name)
+	assert(type(deprecated_global_name) == 'string', "deprecated_global_name should be a string.")
+	assert(type(replacement_global_name) == 'string', "replacement_global_name should be a string.")
+	assert(deprecated_global_name ~= '', "deprecated_global_name should not be empty.")
+	assert(replacement_global_name ~= '', "replacement_global_name should not be empty.")
+	assert(rawget(_G, deprecated_global_name) == nil, "deprecated global does not exist.")
+	if _G[replacement_global_name] == nil then
+		minetest.log('warning', string.format(
+			'Replacement global "%s" does not exists.', replacement_global_name))
+		return
+	end
+	local meta = {
+		deprecated = deprecated_global_name,
+		replacement = replacement_global_name,
+		__index = function(table, key)
+			local meta = getmetatable(table)
+			local dbg = debug.getinfo(2, "lS")
+			minetest.log("warning", string.format(
+				'Accessing deprecated "%s" table, "%s" should be used instead (%s:%d).',
+				meta.deprecated, meta.replacement, (dbg.short_src or 'unknown'),
+				(dbg.currentline or 0)))
+			return _G[meta.replacement][key]
+		end,
+		__newindex = function(table, key, value)
+			local meta = getmetatable(table)
+			local dbg = debug.getinfo(2, "lS")
+			minetest.log("warning", string.format(
+				'Accessing deprecated "%s" table, "%s" should be used instead (%s:%d).',
+				meta.deprecated, meta.replacement, (dbg.short_src or 'unknown'),
+				(dbg.currentline or 0)))
+			_G[meta.replacement][key]=value
+		end,
+	}
+	rawset(_G, deprecated_global_name, {})
+	setmetatable(_G[deprecated_global_name], meta)
+end
+
+
+-- deprecated(1) -- December 2018 - Deprecation of groups display_modpack_node and display_lib_node
+-- Group to be removed from display API register_lbm
+minetest.after(0, function()
+	deprecated_group("display_modpack_node", "display_api")
+	deprecated_group("display_lib_node", "display_api")
+end)
+
+-- deprecated(2) -- December 2018 - Deprecation of display_lib
+deprecated_global_table('display_lib', 'display_api')
diff --git a/display_api/display.lua b/display_api/display.lua
new file mode 100644
index 0000000..fa7c854
--- /dev/null
+++ b/display_api/display.lua
@@ -0,0 +1,325 @@
+--[[
+		display_api mod for Minetest - Library to add dynamic display
+		capabilities to nodes
+		(c) Pierre-Yves Rollo
+
+		This program is free software: you can redistribute it and/or modify
+		it under the terms of the GNU General Public License as published by
+		the Free Software Foundation, either version 3 of the License, or
+		(at your option) any later version.
+
+		This program is distributed in the hope that it will be useful,
+		but WITHOUT ANY WARRANTY; without even the implied warranty of
+		MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+		GNU General Public License for more details.
+
+		You should have received a copy of the GNU General Public License
+		along with this program.  If not, see <http://www.gnu.org/licenses/>.
+--]]
+
+-- Prefered gap between node and entity
+-- Entity positionment is up to mods but it is a good practice to use this
+-- variable as spacing between entity and node
+display_api.entity_spacing = 0.002
+
+-- Maximum entity position relative to the node pos
+local max_entity_pos = 1.5
+
+local wallmounted_rotations = {
+	[0]={x=1, y=0, z=0}, [1]={x=3, y=0, z=0},
+	[2]={x=0, y=3, z=0}, [3]={x=0, y=1, z=0},
+	[4]={x=0, y=0, z=0}, [5]={x=0, y=2, z=0},
+	[6]={x=1, y=0, z=0}, [7]={x=1, y=1, z=1},
+}
+
+local facedir_rotations = {
+	[ 0]={x=0, y=0, z=0}, [ 1]={x=0, y=3, z=0},
+	[ 2]={x=0, y=2, z=0}, [ 3]={x=0, y=1, z=0},
+	[ 4]={x=3, y=0, z=0}, [ 5]={x=0, y=3, z=3},
+	[ 6]={x=1, y=0, z=2}, [ 7]={x=0, y=1, z=1},
+	[ 8]={x=1, y=0, z=0}, [ 9]={x=0, y=3, z=1},
+	[10]={x=3, y=0, z=2}, [11]={x=0, y=1, z=3},
+	[12]={x=0, y=0, z=1}, [13]={x=3, y=0, z=1},
+	[14]={x=2, y=0, z=1}, [15]={x=1, y=0, z=1},
+	[16]={x=0, y=0, z=3}, [17]={x=1, y=0, z=3},
+	[18]={x=2, y=0, z=3}, [19]={x=3, y=0, z=3},
+	[20]={x=0, y=0, z=2}, [21]={x=0, y=1, z=2},
+	[22]={x=0, y=2, z=2}, [23]={x=0, y=3, z=2},
+}
+
+-- Compute other useful values depending on wallmounted and facedir param
+local wallmounted_values = {}
+local facedir_values = {}
+
+local function compute_values(r)
+	local function rx(v) return { x=v.x, y=v.z, z=-v.y} end
+	local function ry(v) return { x=-v.z, y=v.y, z=v.x} end
+	local function rz(v) return { x=v.y, y=-v.x, z=v.z} end
+
+	local d = { x = 0, y = 0, z = 1 }
+	local w = { x = 1, y = 0, z = 0 }
+	local h = { x = 0, y = 1, z = 0 }
+
+	-- Important to keep z rotation first (not same results)
+	for _ = 1, r.z do d, w, h = rz(d), rz(w), rz(h) end
+	for _ = 1, r.x do d, w, h = rx(d), rx(w), rx(h) end
+	for _ = 1, r.y do d, w, h = ry(d), ry(w), ry(h) end
+
+	return {
+		rotation=r, depth=d, width=w, height=h,
+		restricted=(r.x==0 and r.z==0) }
+end
+
+for i, r in pairs(facedir_rotations) do
+	facedir_values[i] = compute_values(r)
+end
+
+for i, r in pairs(wallmounted_rotations) do
+	wallmounted_values[i] = compute_values(r)
+end
+
+-- Detect rotation restriction
+local rotation_restricted = nil
+minetest.register_entity('display_api:dummy_entity', {
+	collisionbox = { 0, 0, 0, 0, 0, 0 },
+	visual = "upright_sprite",
+	textures = {} })
+
+function display_api.is_rotation_restricted()
+	if rotation_restricted == nil then
+		local objref = minetest.add_entity(
+			{x=0, y=0, z=0}, 'display_api:dummy_entity')
+		if objref then
+			rotation_restricted = objref.set_rotation == nil
+			objref:remove()
+		end
+	end
+	return rotation_restricted
+end
+
+-- Clip position property to maximum entity position
+
+local function clip_pos_prop(posprop)
+	if posprop then
+		return math.max(-max_entity_pos, math.min(max_entity_pos, posprop))
+	else
+		return 0
+	end
+end
+
+-- Get values needed for orientation computation of node
+
+local function get_orientation_values(node)
+	local ndef = minetest.registered_nodes[node.name]
+
+	if ndef then
+		local paramtype2 = ndef.paramtype2
+		if paramtype2 == "wallmounted" or paramtype2 == "colorwallmounted" then
+			return wallmounted_values[node.param2 % 8]
+		elseif paramtype2 == "facedir" or paramtype2 == "colorfacedir"  then
+			return facedir_values[node.param2 % 32]
+		else
+			-- No orientation or unknown orientation type
+			return facedir_values[0]
+		end
+	end
+end
+
+-- Gets the display entities attached with a node.
+-- Add missing and remove duplicates
+
+local function get_display_objrefs(pos, create)
+	local objrefs = {}
+	local ndef = minetest.registered_nodes[minetest.get_node(pos).name]
+	if ndef and ndef.display_entities then
+		for _, objref in
+			ipairs(minetest.get_objects_inside_radius(pos, max_entity_pos)) do
+			local entity = objref:get_luaentity()
+			if entity and ndef.display_entities[entity.name] and
+				 entity.nodepos and vector.equals(pos, entity.nodepos) then
+				if objrefs[entity.name] then
+					objref:remove() -- Remove duplicates
+				else
+					objrefs[entity.name] = objref
+				end
+			end
+		end
+		if create then
+			-- Add missing
+			for name, _ in pairs(ndef.display_entities) do
+				if not objrefs[name] then
+					objrefs[name] = minetest.add_entity(pos, name,
+						minetest.serialize({ nodepos = pos }))
+				end
+			end
+		end
+	end
+	return objrefs
+end
+
+--- Force entity update : position and texture
+function display_api.update_entities(pos)
+
+	local node = minetest.get_node(pos)
+	local ndef = minetest.registered_nodes[node.name]
+	local ov = get_orientation_values(node)
+	if not ndef or not ov then
+		return
+	end
+
+	for _, objref in pairs(get_display_objrefs(pos, true)) do
+		local edef = ndef.display_entities[objref:get_luaentity().name]
+		local depth = clip_pos_prop(edef.depth)
+		local right = clip_pos_prop(edef.right)
+		local top = clip_pos_prop(edef.top)
+
+		objref:set_pos({
+			x = pos.x + ov.depth.x*depth + ov.width.x*right - ov.height.x*top,
+			y = pos.y + ov.depth.y*depth + ov.width.y*right - ov.height.y*top,
+			z = pos.z + ov.depth.z*depth + ov.width.z*right - ov.height.z*top,
+		})
+
+		if objref.set_rotation then
+			objref:set_rotation({
+				x = ov.rotation.x*math.pi/2,
+				y = ov.rotation.y*math.pi/2 + (edef.yaw or 0),
+				z = ov.rotation.z*math.pi/2,
+			})
+		else
+			if ov.rotation.x ~=0 or ov.rotation.y ~= 0 then
+				minetest.log("warning", string.format(
+					"[display_api] unable to rotate correctly entity for node at %s without set_rotation method.",
+					minetest.pos_to_string(pos)))
+			end
+			objref:set_yaw(ov.rotation.y*math.pi/2 + (edef.yaw or 0))
+		end
+
+		-- Call on_display_update callback of a node for one of its display entities
+		if edef.on_display_update then
+			edef.on_display_update(pos, objref)
+		end
+	end
+end
+
+--- On_activate callback for display_api entities. Calls on_display_update callbacks
+--- of corresponding node for each entity.
+function display_api.on_activate(entity, staticdata)
+	if entity then
+		if string.sub(staticdata, 1, string.len("return")) == "return" then
+			local data = minetest.deserialize(staticdata)
+			if data and type(data) == "table" then
+				entity.nodepos = data.nodepos
+			end
+			entity.object:set_armor_groups({immortal=1})
+		end
+
+		if entity.nodepos then
+			local node = minetest.get_node(entity.nodepos)
+			local ndef = minetest.registered_nodes[node.name]
+			if ndef and ndef.display_entities then
+				local edef = ndef.display_entities[entity.name]
+				if edef then
+					-- Call on_display_update callback of the entity to build texture
+					if edef.on_display_update then
+						edef.on_display_update(entity.nodepos, entity.object)
+					end
+					return
+				end
+			end
+		end
+		-- If we got here, this display entity is buggy and should be removed
+		entity.object:remove()
+	end
+end
+
+--- On_place callback for display_api items.
+-- Does nothing more than preventing node from being placed on ceiling or ground
+-- TODO:When MT<5 is not in use anymore, simplify this
+function display_api.on_place(itemstack, placer, pointed_thing, override_param2)
+	local ndef = itemstack:get_definition()
+	local dir = {
+		x = pointed_thing.under.x - pointed_thing.above.x,
+		y = pointed_thing.under.y - pointed_thing.above.y,
+		z = pointed_thing.under.z - pointed_thing.above.z,
+	}
+
+	local rotation_restriction = display_api.is_rotation_restricted()
+
+	if rotation_restriction then
+		-- If item is not placed on a wall, use the player's view direction instead
+		if dir.x == 0 and dir.z == 0 then
+			dir = placer:get_look_dir()
+		end
+		dir.y = 0
+	end
+
+	local param2 = 0
+	if ndef then
+		if ndef.paramtype2 == "wallmounted" or
+			ndef.paramtype2 == "colorwallmounted" then
+			param2 = minetest.dir_to_wallmounted(dir)
+
+		elseif ndef.paramtype2 == "facedir" or
+			ndef.paramtype2 == "colorfacedir"  then
+			param2 = minetest.dir_to_facedir(dir, not rotation_restriction)
+		end
+	end
+	return minetest.item_place(itemstack, placer, pointed_thing,
+		param2 + (override_param2 or 0))
+end
+
+--- On_construct callback for display_api items.
+-- Creates entities and update them.
+function display_api.on_construct(pos)
+	display_api.update_entities(pos)
+end
+
+--- On_destruct callback for display_api items.
+-- Removes entities.
+function display_api.on_destruct(pos)
+	for _, objref in pairs(get_display_objrefs(pos)) do
+		objref:remove()
+	end
+end
+
+-- On_rotate (screwdriver) callback for display_api items. Prevents invalid
+-- rotations and reorients entities.
+function display_api.on_rotate(pos, node, user, _, new_param2)
+	node.param2 = new_param2
+	local ov = get_orientation_values(node)
+	if not ov then
+		return
+	end
+
+	if ov.restricted or not display_api.is_rotation_restricted() then
+		minetest.swap_node(pos, node)
+		display_api.update_entities(pos)
+		return true
+	else
+		return false
+	end
+end
+
+--- Creates display entity with some fields and the on_activate callback
+function display_api.register_display_entity(entity_name)
+	if not minetest.registered_entities[entity_name] then
+		minetest.register_entity(':'..entity_name, {
+			collisionbox = { 0, 0, 0, 0, 0, 0 },
+			visual = "upright_sprite",
+			textures = {},
+			on_activate = display_api.on_activate,
+			get_staticdata = function(self)
+				return minetest.serialize({ nodepos = self.nodepos })
+			end,
+		})
+	end
+end
+
+minetest.register_lbm({
+	label = "Update display_api entities",
+	name = "display_api:update_entities",
+	run_at_every_load = true,
+	nodenames = {"group:display_api",
+		"group:display_modpack_node", "group:display_lib_node"}, -- See deprecated(1)
+	action = function(pos, node) display_api.update_entities(pos) end,
+})
diff --git a/display_api/init.lua b/display_api/init.lua
new file mode 100644
index 0000000..f1e54e8
--- /dev/null
+++ b/display_api/init.lua
@@ -0,0 +1,31 @@
+--[[
+		display_api mod for Minetest - Library to add dynamic display
+		capabilities to nodes
+		(c) Pierre-Yves Rollo
+
+		This program is free software: you can redistribute it and/or modify
+		it under the terms of the GNU General Public License as published by
+		the Free Software Foundation, either version 3 of the License, or
+		(at your option) any later version.
+
+		This program is distributed in the hope that it will be useful,
+		but WITHOUT ANY WARRANTY; without even the implied warranty of
+		MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+		GNU General Public License for more details.
+
+		You should have received a copy of the GNU General Public License
+		along with this program.  If not, see <http://www.gnu.org/licenses/>.
+--]]
+
+-- Global variables
+-------------------
+
+display_api = {}
+display_api.name = minetest.get_current_modname()
+display_api.path = minetest.get_modpath(display_api.name)
+
+-- Inclusions
+-------------
+
+dofile(display_api.path.."/display.lua")
+dofile(display_api.path.."/deprecation.lua")
diff --git a/display_api/mod.conf b/display_api/mod.conf
new file mode 100644
index 0000000..d0b1da7
--- /dev/null
+++ b/display_api/mod.conf
@@ -0,0 +1,2 @@
+name=display_api
+description=A library for adding dynamic textures on nodes