Files
sporel-lib-core.puppet/init.lua
Axel Meyer e62671060e feat: initial implementation with build_rig + build_animation
Validates and cooks rig + animation data into internal representations:
- build_rig: parses bones (with parent-resolution to object refs) and
  tracks (with bone-uniqueness validation). Converts rest angles
  from JSON degrees to radians.
- build_animation: validates each keyframe references only bones in
  the animation's declared track. Converts keyframe angles from
  degrees to radians.

Remaining functions (sample_animation, spawn, update, look-at,
procedural, render, lifecycle) follow in subsequent commits.
2026-05-17 19:54:27 +02:00

182 lines
6.7 KiB
Lua

-- lib-core.puppet v0.1.0
-- Skeletal animation: skeleton + bones + tracks + rest + keyframe
-- + procedural + look-at constraint. No footplant in v0.1.
local M = {}
-- ====================================================================
-- Module state (lib-singleton)
-- ====================================================================
local all_puppets = {} -- {[handle] = puppet_instance}
local next_handle = 1
-- ====================================================================
-- Utility helpers
-- ====================================================================
local function deep_copy(t)
if type(t) ~= "table" then return t end
local copy = {}
for k, v in pairs(t) do copy[k] = deep_copy(v) end
return copy
end
local function clamp_angle_rad(a)
-- Normalize to [-pi, pi]
local pi = math.pi
while a > pi do a = a - 2 * pi end
while a < -pi do a = a + 2 * pi end
return a
end
-- Subsequent tasks add: sample_animation,
-- spawn, despawn, update, render, set_look_target, clear_look_target,
-- bone_angle, set_procedural, clear_procedural, write_bone, play, stop,
-- stop_all, is_playing, position, facing, move_to, register_animation,
-- load_rig, load_animation.
-- ====================================================================
-- Rig validation + build
-- ====================================================================
function M.build_rig(rig_table)
if type(rig_table) ~= "table" then
error("puppet.build_rig: rig_table must be a table")
end
if type(rig_table.bones) ~= "table" or #rig_table.bones == 0 then
error("puppet.build_rig: rig.bones must be a non-empty array")
end
if type(rig_table.tracks) ~= "table" then
error("puppet.build_rig: rig.tracks must be an array")
end
-- Build bones_by_id with shallow copies of rest pose.
local bones_by_id = {}
for _, b in ipairs(rig_table.bones) do
if type(b.id) ~= "string" then
error("puppet.build_rig: bone.id must be string")
end
if bones_by_id[b.id] ~= nil then
error("puppet.build_rig: duplicate bone id: " .. b.id)
end
bones_by_id[b.id] = {
id = b.id,
parent = nil, -- resolved below
rest = {
x = b.rest.x, y = b.rest.y,
-- JSON angles in degrees; convert to radians once.
angle = math.rad(b.rest.angle or 0),
},
look_at = (b.look_at == true),
color = b.color or { 200, 200, 200 },
}
end
-- Resolve parents (object references).
for _, b_src in ipairs(rig_table.bones) do
local b = bones_by_id[b_src.id]
if b_src.parent ~= nil then
local parent_obj = bones_by_id[b_src.parent]
if parent_obj == nil then
error("puppet.build_rig: parent '" .. tostring(b_src.parent)
.. "' of bone '" .. b.id .. "' not found")
end
b.parent = parent_obj
end
end
-- Build tracks + validate each bone is in EXACTLY ONE track.
local bone_to_track = {}
local tracks_by_id = {}
for _, t in ipairs(rig_table.tracks) do
if type(t.id) ~= "string" then
error("puppet.build_rig: track.id must be string")
end
if tracks_by_id[t.id] ~= nil then
error("puppet.build_rig: duplicate track id: " .. t.id)
end
local bones_in_track = {}
for _, bid in ipairs(t.bones) do
if bones_by_id[bid] == nil then
error("puppet.build_rig: track '" .. t.id
.. "' references unknown bone '" .. bid .. "'")
end
if bone_to_track[bid] ~= nil then
error("puppet.build_rig: bone '" .. bid
.. "' assigned to multiple tracks ('"
.. bone_to_track[bid] .. "' and '" .. t.id .. "')")
end
bone_to_track[bid] = t.id
bones_in_track[#bones_in_track + 1] = bid
end
tracks_by_id[t.id] = { id = t.id, bones = bones_in_track }
end
return {
id = rig_table.id or "anonymous",
bones = rig_table.bones, -- keep original-order array
bones_by_id = bones_by_id,
tracks_by_id = tracks_by_id,
bone_to_track = bone_to_track,
}
end
-- ====================================================================
-- Animation validation + build
-- ====================================================================
function M.build_animation(anim_table, rig)
if type(anim_table) ~= "table" then
error("puppet.build_animation: anim_table must be a table")
end
if type(anim_table.track) ~= "string" then
error("puppet.build_animation: animation.track must be string")
end
if rig.tracks_by_id[anim_table.track] == nil then
error("puppet.build_animation: animation.track '"
.. anim_table.track .. "' not found in rig")
end
if type(anim_table.duration) ~= "number" or anim_table.duration <= 0 then
error("puppet.build_animation: animation.duration must be positive number")
end
if type(anim_table.keyframes) ~= "table" or #anim_table.keyframes == 0 then
error("puppet.build_animation: animation.keyframes must be non-empty array")
end
-- Validate each keyframe: t in [0, duration], bones referenced are in this animation's track.
local track_bones = {}
for _, bid in ipairs(rig.tracks_by_id[anim_table.track].bones) do
track_bones[bid] = true
end
local keyframes = {}
for i, kf in ipairs(anim_table.keyframes) do
if type(kf.t) ~= "number" or kf.t < 0 or kf.t > anim_table.duration + 1e-9 then
error("puppet.build_animation: keyframe[" .. i .. "].t out of [0, duration]")
end
local cooked = { t = kf.t, bones = {} }
for k, v in pairs(kf) do
if k ~= "t" then
if rig.bones_by_id[k] == nil then
error("puppet.build_animation: keyframe references unknown bone '" .. k .. "'")
end
if not track_bones[k] then
error("puppet.build_animation: keyframe writes bone '" .. k
.. "' which is not in animation's track '" .. anim_table.track .. "'")
end
cooked.bones[k] = {
angle = math.rad(v.angle or 0), -- JSON degrees → radians
}
end
end
keyframes[i] = cooked
end
return {
id = anim_table.id or "anonymous",
track = anim_table.track,
duration = anim_table.duration,
loop = (anim_table.loop == true),
keyframes = keyframes,
}
end
return M