creatura/boids.lua

233 lines
6.7 KiB
Lua
Raw Normal View History

2022-02-10 16:32:53 -08:00
-----------
-- Boids --
-----------
2022-08-27 20:07:53 -07:00
local abs = math.abs
2022-10-12 14:37:44 -07:00
local atan2 = math.atan2
local sin = math.sin
local cos = math.cos
local function average_angle(tbl)
local sum_sin, sum_cos = 0, 0
for _, v in pairs(tbl) do
sum_sin = sum_sin + sin(v)
sum_cos = sum_cos + cos(v)
end
return atan2(sum_sin, sum_cos)
end
2022-02-10 16:32:53 -08:00
local function average(tbl)
local sum = 0
for _,v in pairs(tbl) do -- Get the sum of all numbers in t
sum = sum + v
end
return sum / #tbl
2022-02-10 16:32:53 -08:00
end
2022-10-12 14:37:44 -07:00
local function interp_rad(a, b, w)
local cs = (1 - w) * cos(a) + w * cos(b)
local sn = (1 - w) * sin(a) + w * sin(b)
return atan2(sn, cs)
2022-02-10 16:32:53 -08:00
end
local vec_add = vector.add
2022-10-12 14:37:44 -07:00
local vec_dir = vector.direction
local vec_dist = vector.distance
2022-02-10 16:32:53 -08:00
local vec_divide = vector.divide
2022-10-12 14:37:44 -07:00
local vec_normal = vector.normalize
2022-02-10 16:32:53 -08:00
local function get_average_pos(vectors)
local sum = {x = 0, y = 0, z = 0}
for _, vec in pairs(vectors) do sum = vec_add(sum, vec) end
return vec_divide(sum, #vectors)
2022-02-10 16:32:53 -08:00
end
local function dist_2d(pos1, pos2)
local a = vector.new(
pos1.x,
0,
pos1.z
)
local b = vector.new(
pos2.x,
0,
pos2.z
)
return vec_dist(a, b)
2022-02-10 16:32:53 -08:00
end
local yaw2dir = minetest.yaw_to_dir
local dir2yaw = minetest.dir_to_yaw
-- Get Boid Members --
2022-10-12 14:37:44 -07:00
function creatura.get_boid_cached(self)
local pos = self.object:get_pos()
if not pos then return end
local radius = self.tracking_range * 0.5 or 4
local members = self._movement_data.boids or {}
local max_boids = self.max_boids or 7
if #members > 0 then
for i = #members, 1, -1 do
local object = members[i]
if not object or not object:get_yaw() then members[i] = nil end
end
if #members >= max_boids then return members end
end
local objects = minetest.get_objects_inside_radius(pos, radius)
if #objects < 2 then return {} end
for _, object in ipairs(objects) do
local ent = object and object ~= self.object and object:get_luaentity()
if ent
and ent.name == self.name then
local move_data = ent._movement_data
if move_data
and (not move_data.boids
or #move_data.boids < max_boids) then
table.insert(members, object)
end
end
if #members >= max_boids then break end
end
self._movement_data.boids = members
return members
end
-- Calculate Boid Movement Direction
function creatura.get_boid_dir(self)
local pos = self.object:get_pos()
if not pos then return end
local boids = creatura.get_boid_cached(self)
if #boids < 2 then return end
local pos_no, pos_sum = 0, {x = 0, y = 0, z = 0}
local sum_sin, sum_cos = 0, 0
local lift_no, lift_sum = 0, 0
local vel
local boid_pos
local closest_pos
for _, object in ipairs(boids) do
if object then
2023-03-14 20:04:14 -07:00
boid_pos, vel = object:get_pos(), object:get_velocity()
2022-10-17 14:25:33 -07:00
if boid_pos then
2023-03-14 20:04:14 -07:00
vel = vec_normal(vel)
2022-10-17 14:25:33 -07:00
local obj_yaw = object:get_yaw()
pos_no, pos_sum = pos_no + 1, vec_add(pos_sum, boid_pos)
sum_sin, sum_cos = sum_sin + sin(obj_yaw), sum_cos + cos(obj_yaw)
lift_no, lift_sum = lift_no + 1, lift_sum + vel.y
if not closest_pos
or vec_dist(pos, boid_pos) < vec_dist(pos, closest_pos) then
closest_pos = boid_pos
end
2022-10-12 14:37:44 -07:00
end
end
end
if not closest_pos then return end
local center = vec_divide(pos_sum, pos_no)
local lift = lift_sum / lift_no
local angle_sin, angle_cos
local radius = self.tracking_range * 0.5 or 4
local dist_factor = (radius - vec_dist(pos, closest_pos)) / radius
local alignment = atan2(sum_sin, sum_cos)
local seperation = dir2yaw(vec_dir(closest_pos, pos))
local cohesion = dir2yaw(vec_dir(pos, center))
if dist_factor > 0.9 then
seperation = interp_rad(alignment, seperation, 0.5)
angle_sin, angle_cos = sin(seperation), cos(seperation)
else
angle_sin, angle_cos = sin(cohesion), cos(cohesion)
end
local angle = atan2(angle_sin + sin(alignment), angle_cos + cos(alignment))
local dir = yaw2dir(angle)
dir.y = lift
return vector.normalize(dir), boids
end
-- Deprecated
2022-02-10 16:32:53 -08:00
function creatura.get_boid_members(pos, radius, name)
local objects = minetest.get_objects_inside_radius(pos, radius)
if #objects < 2 then return {} end
local members = {}
local max_boid = minetest.registered_entities[name].max_boids or 7
for i = 1, #objects do
if #members > max_boid then break end
local object = objects[i]
if object:get_luaentity()
and object:get_luaentity().name == name then
table.insert(members, object)
end
end
2022-08-09 15:18:47 -07:00
if #members > 1 then
for _, object in ipairs(members) do
local ent = object and object:get_luaentity()
if ent then
ent._movement_data.boids = members
end
end
end
return members
2022-02-10 16:32:53 -08:00
end
function creatura.get_boid_angle(self, _boids, range)
local pos = self.object:get_pos()
local boids = _boids or creatura.get_boid_members(pos, range or 4, self.name)
if #boids < 3 then return end
local yaw = self.object:get_yaw()
local lift = self.object:get_velocity().y
-- Add Boid data to tables
local closest_pos
local positions = {}
local angles = {}
local lifts = {}
for i = 1, #boids do
local boid = boids[i]
if boid:get_pos() then
2022-08-27 20:07:53 -07:00
local vel = boid:get_velocity()
if boid ~= self.object
and (abs(vel.x) > 0.1
or abs(vel.z) > 0.1) then
local boid_pos = boid:get_pos()
table.insert(positions, boid_pos)
table.insert(lifts, vec_normal(vel).y)
table.insert(angles, boid:get_yaw())
if not closest_pos
or vec_dist(pos, boid_pos) < vec_dist(pos, closest_pos) then
closest_pos = boid_pos
end
end
end
end
if #positions < 3 then return end
local center = get_average_pos(positions)
local dir2closest = vec_dir(pos, closest_pos)
-- Calculate Parameters
local alignment = average_angle(angles)
center = vec_add(center, yaw2dir(alignment))
local dir2center = vec_dir(pos, center)
local seperation = yaw + -(dir2yaw(dir2closest) - yaw)
local cohesion = dir2yaw(dir2center)
local params = {alignment}
if dist_2d(pos, closest_pos) < (self.boid_seperation or self.width * 3) then
table.insert(params, seperation)
elseif dist_2d(pos, center) > (#boids * 0.33) * (self.boid_seperation or self.width * 3) then
table.insert(params, cohesion)
end
-- Vertical Params
local vert_alignment = average(lifts)
local vert_seperation = (self.speed or 2) * -dir2closest.y
local vert_cohesion = (self.speed or 2) * dir2center.y
local vert_params = {vert_alignment}
if math.abs(pos.y - closest_pos.y) < (self.boid_seperation or self.width * 3) then
table.insert(vert_params, vert_seperation)
elseif math.abs(pos.y - closest_pos.y) > 1.5 * (self.boid_seperation or self.width * 3) then
table.insert(vert_params, vert_cohesion + (lift - vert_cohesion) * 0.1)
end
2022-08-05 17:42:37 -07:00
return average_angle(params), average(vert_params)
2022-10-14 20:07:51 -07:00
end