display_modpack/display_api/display.lua

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--[[
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
-- Miscelaneous values depending on wallmounted param2
local wallmounted_values = {
[2]={dx=-1, dz=0, rx=0, rz=-1, yaw=-math.pi/2},
[3]={dx=1, dz=0, rx=0, rz=1, yaw=math.pi/2 },
[4]={dx=0, dz=-1, rx=1, rz=0, yaw=0 },
[5]={dx=0, dz=1, rx=-1, rz=0, yaw=math.pi }
}
-- Miscelaneous values depending on facedir param2
local facedir_values = {
[0]={dx=0, dz=-1, rx=1, rz=0, yaw=0 },
[1]={dx=-1, dz=0, rx=0, rz=-1, yaw=-math.pi/2},
[2]={dx=0, dz=1, rx=-1, rz=0, yaw=math.pi },
[3]={dx=1, dz=0, rx=0, rz=1, yaw=math.pi/2 }
}
-- dx/dy = depth vector, rx/ly = right vector, yaw = yaw of entity,
local function get_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]
end
end
end
--- Gets the display entities attached with a node. Removes extra ones
local function get_entities(pos)
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
end
return objrefs
end
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
--- (Create and) place display entities according to the node orientation
local function place_entities(pos)
local node = minetest.get_node(pos)
local ndef = minetest.registered_nodes[node.name]
local values = get_values(node)
local objrefs = get_entities(pos)
if values and ndef and ndef.display_entities then
for entity_name, props in pairs(ndef.display_entities) do
local depth = clip_pos_prop(props.depth)
local right = clip_pos_prop(props.right)
local top = clip_pos_prop(props.top)
if not objrefs[entity_name] then
objrefs[entity_name] = minetest.add_entity(pos, entity_name,
minetest.serialize({ nodepos = pos }))
end
objrefs[entity_name]:set_pos({
x = pos.x - values.dx * depth + values.rx * right,
y = pos.y - top,
z = pos.z - values.dz * depth + values.rz * right})
objrefs[entity_name]:set_yaw(values.yaw + (props.yaw or 0))
end
end
return objrefs
end
--- Entity update
function update_entity(entity)
if not entity then
return
end
if not entity.nodepos then
entity.object:remove() -- Remove old/buggy entity
return
end
local node = minetest.get_node(entity.nodepos)
local ndef = minetest.registered_nodes[node.name]
if ndef and ndef.display_entities and
ndef.display_entities[entity.name] and
ndef.display_entities[entity.name].on_display_update
then
-- Call on_display_update callback of a node for one of its display entities
ndef.display_entities[entity.name].on_display_update(entity.nodepos,
entity.object)
else
-- Display node has been removed, remove entity also
entity.object:remove()
end
end
--- Force entity update
function display_api.update_entities(pos)
for _, objref in pairs(place_entities(pos)) do
update_entity(objref:get_luaentity())
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
update_entity(entity)
end
end
--- On_place callback for display_api items.
-- Does nothing more than preventing node from being placed on ceiling or ground
function display_api.on_place(itemstack, placer, pointed_thing, override_param2)
local ndef = itemstack:get_definition()
local above = pointed_thing.above
local under = pointed_thing.under
local dir = {x = under.x - above.x, y = 0, z = under.z - above.z}
-- 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()
dir.y = 0
end
local param2 = 0
if ndef then
local paramtype2 = ndef.paramtype2
if paramtype2 == "wallmounted" or paramtype2 == "colorwallmounted" then
param2 = minetest.dir_to_wallmounted(dir)
elseif paramtype2 == "facedir" or paramtype2 == "colorfacedir" then
param2 = minetest.dir_to_facedir(dir)
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_entities(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
if get_values(node) then
minetest.swap_node(pos, node)
place_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)
2018-12-04 18:01:36 +01:00
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,
})