ai-chatbot/lib/video-canvas/director-extensions.ts

import { resizeObjectTracks } from "./director-object-tracks";
import {
  defaultDirectorMotion,
  resizeDirectorMotion,
  type DirectorPose,
  type DirectorMotion,
} from "./director-motion";
import type {
  DirectorScene,
  DirectorCamera,
  DirectorVector,
  DirectorObject,
} from "./director-scene";
export function commitDirectorScene(previous: DirectorScene, next: DirectorScene): DirectorScene {
  const motionTracks = {
    ...previous.motionTracks,
    ...next.motionTracks,
    [previous.activeCameraId]: previous.motion,
  };
  const motion =
    previous.activeCameraId === next.activeCameraId
      ? next.motion
      : motionTracks[next.activeCameraId] || {
          ...defaultDirectorMotion(),
          duration: previous.motion.duration,
        };
  motionTracks[next.activeCameraId] = motion;
  for (const id of Object.keys(motionTracks))
    if (!next.cameras.some((c) => c.id === id)) delete motionTracks[id];
  let objectTracks = next.objectTracks;
  if (
    previous.activeCameraId === next.activeCameraId &&
    previous.motion.duration !== next.motion.duration
  ) {
    for (const id of Object.keys(motionTracks))
      if (id !== next.activeCameraId)
        motionTracks[id] = resizeDirectorMotion(motionTracks[id], next.motion.duration);
    objectTracks = resizeObjectTracks(objectTracks, previous.motion.duration, next.motion.duration);
  }
  objectTracks = Object.fromEntries(
    Object.entries(objectTracks || {}).filter(([id]) => next.objects.some((o) => o.id === id)),
  );
  return { ...next, motion, motionTracks, objectTracks };
}
export function resolveDirectorCamera(scene: DirectorScene, pose?: DirectorPose): DirectorCamera {
  const camera = scene.cameras.find((c) => c.id === scene.activeCameraId) || scene.cameras[0];
  const subject = scene.objects.find((o) => o.id === camera.followObjectId);
  const result = { ...camera, ...pose };
  if (subject) {
    const target: DirectorVector = [
      subject.position[0],
      subject.position[1] + subject.scale[1],
      subject.position[2],
    ];
    if (Math.hypot(...target.map((v, i) => v - result.position[i])) > 0.001) result.target = target;
  }
  return result;
}
export function cameraAngles(camera: DirectorPose) {
  const [x, y, z] = camera.target.map((v, i) => v - camera.position[i]);
  return {
    yaw: (Math.atan2(x, -z) * 180) / Math.PI,
    pitch: (Math.atan2(y, Math.hypot(x, z)) * 180) / Math.PI,
  };
}
export function rotateDirectorCamera(
  camera: DirectorPose,
  yaw: number,
  pitch: number,
): DirectorVector {
  const distance = Math.max(
    0.01,
    Math.hypot(...camera.target.map((v, i) => v - camera.position[i])),
  );
  const y = (yaw * Math.PI) / 180,
    p = (Math.max(-89, Math.min(89, pitch)) * Math.PI) / 180;
  return [
    camera.position[0] + distance * Math.sin(y) * Math.cos(p),
    camera.position[1] + distance * Math.sin(p),
    camera.position[2] - distance * Math.cos(y) * Math.cos(p),
  ];
}
export const directorBodies = {
  标准: [1, 1, 1],
  高挑: [0.85, 1.15, 1],
  矮壮: [1.2, 0.85, 1.1],
  纤细: [0.7, 1, 0.95],
  健壮: [1.35, 1.08, 1],
  宽厚: [1.5, 1, 1.05],
  幼童: [0.7, 0.6, 1.4],
  大头: [1, 0.85, 1.5],
} as const;
export function createDirectorCrowd(
  object: DirectorObject,
  existingCount: number,
  id: () => string,
) {
  if (existingCount + 8 > 200) throw Error("场景最多支持 200 个对象");
  return Array.from({ length: 8 }, (_, index) => {
    const cell = index + 1;
    return {
      ...object,
      id: id(),
      name: `${object.name} 阵列 ${cell}`,
      position: [
        object.position[0] + (cell % 3) * 1.5,
        object.position[1],
        object.position[2] + Math.floor(cell / 3) * 1.5,
      ] as DirectorVector,
    };
  });
}
export function transformDirectorMotion(
  motion: DirectorMotion,
  translation: DirectorVector,
  yawDegrees: number,
): DirectorMotion {
  const origin = motion.keyframes[0]?.target || [0, 0, 0],
    angle = (yawDegrees * Math.PI) / 180;
  const transform = (v: DirectorVector): DirectorVector => {
    const x = v[0] - origin[0],
      z = v[2] - origin[2];
    return [
      origin[0] + x * Math.cos(angle) - z * Math.sin(angle) + translation[0],
      v[1] + translation[1],
      origin[2] + x * Math.sin(angle) + z * Math.cos(angle) + translation[2],
    ];
  };
  return {
    ...motion,
    keyframes: motion.keyframes.map((k) => ({
      ...k,
      position: transform(k.position),
      target: transform(k.target),
    })),
  };
}