music-video-gen/flow-state/src/engine/Layer.js
2026-08-06 10:29:32 +02:00

297 lines
10 KiB
JavaScript

import * as THREE from 'three';
import { VERTEX_SHADER, buildFragmentShader, AUDIO_UNIFORMS, SIGNATURE_UNIFORMS } from './shader-contract.js';
import { signatureUniforms, NEUTRAL_UNIFORMS } from '../look/Personality.js';
import { clampValue } from '../params/schema.js';
export const BLEND_MODES = ['normal', 'add', 'screen', 'multiply', 'overlay', 'softlight'];
/**
* Map a raw feature value through a response curve. `spike` squares the input so
* beat-driven params punch rather than wobble; `smooth` rounds the shoulders so
* slow features don't step.
*/
function applyResponse(value, response) {
switch (response) {
case 'spike': return value * value;
case 'smooth': return value * value * (3 - 2 * value);
case 'inverse': return 1 - value;
default: return value;
}
}
/**
* The standard uniform dictionary every fragment layer is compiled against.
* Shared by ShaderLayer and the OSD plate so a text layer honours exactly the
* same contract — palette, audio features and personality — as a scene.
*/
export function buildShaderUniforms(module, baseParams, seed) {
const uniforms = {
u_resolution: { value: new THREE.Vector2(1, 1) },
u_aspect: { value: 1 },
u_pixelScale: { value: 1 },
u_time: { value: 0 },
u_frame: { value: 0 },
u_progress: { value: 0 },
u_seed: { value: (seed >>> 0) % 100000 / 1000 },
u_opacity: { value: 1 },
u_colors: { value: Array.from({ length: 8 }, () => new THREE.Vector3(1, 1, 1)) },
u_colorCount: { value: 1 },
u_prev: { value: null },
u_hasPrev: { value: 0 },
};
for (const name of AUDIO_UNIFORMS) uniforms[name] = { value: 0 };
for (const [name, type] of Object.entries(SIGNATURE_UNIFORMS)) {
const v = NEUTRAL_UNIFORMS[name];
uniforms[name] = { value: type === 'vec2' ? new THREE.Vector2(v[0], v[1]) : v };
}
for (const [name, def] of Object.entries(module.params || {})) {
if (!def.uniform || def.type === 'palette') continue;
const v = baseParams[name];
uniforms[def.uniform] = {
value: def.type === 'vec2'
? new THREE.Vector2(v ? v[0] : 0, v ? v[1] : 0)
: def.type === 'bool' ? (v ? 1 : 0) : (v || 0),
};
}
return uniforms;
}
/**
* Push the per-frame values into a fragment layer's uniforms: the frame, the
* audio features, the palette and the personality. Shared by scene layers and
* the OSD plate so they all see the same inputs — the same render path, so
* what a scene honours a plate honours too.
*/
export function setFrameUniforms(layer, renderer, target, ctx) {
const u = layer.uniforms;
const { timeline, features, prevTexture } = ctx;
const w = target ? target.width : renderer.width;
const h = target ? target.height : renderer.height;
u.u_resolution.value.set(w, h);
u.u_aspect.value = w / h;
u.u_pixelScale.value = h / 1080; // reference height; keeps 720p ≡ 4K
u.u_time.value = timeline.time;
u.u_frame.value = timeline.frame;
u.u_progress.value = timeline.progress;
u.u_opacity.value = layer.opacity;
if (features) {
for (const name of AUDIO_UNIFORMS) {
const key = name.slice(2); // u_bandLow -> bandLow
const v = features[key];
u[name].value = v === undefined ? 0 : v;
}
}
const colors = layer.palette || [];
u.u_colorCount.value = Math.max(1, Math.min(8, colors.length));
for (let i = 0; i < 8; i++) {
const c = colors[i % Math.max(1, colors.length)];
if (c) u.u_colors.value[i].set(c[0], c[1], c[2]);
}
const signature = signatureUniforms(layer.personality, layer.module);
for (const [name, type] of Object.entries(SIGNATURE_UNIFORMS)) {
const v = signature[name];
if (type === 'vec2') u[name].value.set(v[0], v[1]);
else u[name].value = v;
}
// Framing is per shot and wins over the personality's neutral defaults —
// it is the operator's hand on a shot that is already set up, not a trait
// of the track. See look/framing.js.
if (layer.framing) {
u.u_sigFrameScale.value = layer.framing.scale;
u.u_sigFrameShift.value.set(layer.framing.shift[0], layer.framing.shift[1]);
}
u.u_prev.value = prevTexture || null;
u.u_hasPrev.value = prevTexture ? 1 : 0;
}
/** Common surface for shader layers and 3D layers, so Compositor holds one type. */
export class Layer {
constructor({ module, params = {}, seed = 1, opacity = 1, blend = 'normal' }) {
this.module = module;
this.baseParams = { ...params };
this.params = { ...params };
this.seed = seed >>> 0;
this.opacity = opacity;
this.blend = blend;
this.palette = [];
this.personality = null;
}
/**
* The track's production design. Constant for the whole video — see
* look/Personality.js — and pushed in the same way the palette is, so a
* layer never reaches for global state.
*/
setPersonality(personality) {
this.personality = personality;
return this;
}
setParams(params) {
this.baseParams = { ...this.baseParams, ...params };
return this;
}
setPalette(colors) {
this.palette = colors;
return this;
}
/**
* This shot's FRAMING — a per-shot scale/recentre pushed by the arc driver,
* applied inside sigCamera. A layer that is never framed renders at the
* neutral (full-frame) scale, so nothing predating framing changes.
*/
setFraming(framing) {
this.framing = framing || null;
return this;
}
/** Resolve base params + reactive modulation into the values used this frame. */
resolveParams(features) {
const defs = this.module.params || {};
const reactive = this.module.reactive || {};
const out = this.params;
for (const name of Object.keys(defs)) out[name] = this.baseParams[name];
if (!features) return out;
for (const [name, r] of Object.entries(reactive)) {
const def = defs[name];
if (!def || def.type === 'palette') continue;
// Rate params multiply absolute time; modulating them jumps the phase
// by elapsed * delta. See params/schema.js RATE_FLAG.
if (def.rate) continue;
const raw = features[r.feature];
if (raw === undefined) continue;
const shaped = applyResponse(Math.max(0, Math.min(1, raw)), r.response);
const [lo, hi] = def.range || [0, 1];
const span = hi - lo;
const base = out[name] !== undefined ? out[name] : lo;
if (def.type === 'vec2') {
out[name] = [
clampValue(def, [base[0] + shaped * r.amount * span, 0])[0],
clampValue(def, [0, base[1] + shaped * r.amount * span])[1],
];
} else if (def.type === 'bool') {
out[name] = base;
} else {
out[name] = clampValue(def, base + shaped * r.amount * span);
}
}
return out;
}
render() { throw new Error('Layer.render not implemented'); }
dispose() {}
}
/** A fullscreen fragment-shader scene. The common case. */
export class ShaderLayer extends Layer {
constructor(options) {
super(options);
this.uniforms = buildShaderUniforms(this.module, this.baseParams, this.seed);
this.material = new THREE.ShaderMaterial({
vertexShader: VERTEX_SHADER,
fragmentShader: buildFragmentShader(this.module),
uniforms: this.uniforms,
depthTest: false,
depthWrite: false,
});
}
render(renderer, target, ctx) {
const { features } = ctx;
setFrameUniforms(this, renderer, target, ctx);
const resolved = this.resolveParams(features);
for (const [name, def] of Object.entries(this.module.params || {})) {
if (!def.uniform || def.type === 'palette') continue;
const target_u = this.uniforms[def.uniform];
const v = resolved[name];
if (v === undefined) continue;
if (def.type === 'vec2') target_u.value.set(v[0], v[1]);
else if (def.type === 'bool') target_u.value = v ? 1 : 0;
else target_u.value = v;
}
renderer.blit(this.material, target);
}
dispose() {
this.material.dispose();
}
}
/**
* A layer backed by a real three.js scene — particles, geometry, camera motion.
* The module supplies build/update hooks; everything determinism-related (seeded
* rng, fixed dt, explicit re-seed at section boundaries) is handled here so 3D
* modules can't accidentally reintroduce wall-clock or Math.random.
*/
export class SceneLayer extends Layer {
constructor(options) {
super(options);
this.scene = new THREE.Scene();
this.camera = new THREE.PerspectiveCamera(60, 16 / 9, 0.1, 200);
this.camera.position.set(0, 0, 5);
this.instance = this.module.build({
scene: this.scene,
camera: this.camera,
seed: this.seed,
params: this.baseParams,
THREE,
});
}
render(renderer, target, ctx) {
const { timeline, features } = ctx;
const w = target ? target.width : renderer.width;
const h = target ? target.height : renderer.height;
if (this.camera.aspect !== w / h) {
this.camera.aspect = w / h;
this.camera.updateProjectionMatrix();
}
const resolved = this.resolveParams(features);
this.module.update({
instance: this.instance,
scene: this.scene,
camera: this.camera,
timeline,
features: features || {},
params: resolved,
palette: this.palette,
personality: this.personality,
opacity: this.opacity,
THREE,
});
renderer.renderScene(this.scene, this.camera, target, true);
}
dispose() {
this.scene.traverse((obj) => {
if (obj.geometry) obj.geometry.dispose();
if (obj.material) {
const mats = Array.isArray(obj.material) ? obj.material : [obj.material];
mats.forEach((m) => m.dispose());
}
});
}
}
export function createLayer(module, options) {
if (module.kind === 'layer3d') return new SceneLayer({ module, ...options });
return new ShaderLayer({ module, ...options });
}