cocos-nodejs-io-game/apps/server/src/Common/Binary.ts

import { ApiMsgEnum, InputTypeEnum } from "./Enum";
import { strdecode, strencode } from "./Utils";

const encodeActorMove = (proto: ApiMsgEnum, data: any, view: DataView, index: number) => {
  view.setUint8(index++, data.type)
  view.setUint8(index++, data.id)
  view.setFloat32(index, data.direction.x)
  index += 4
  view.setFloat32(index, data.direction.y)
  index += 4
  view.setFloat32(index, data.dt)
  index += 4
}

const encodeWeaponShoot = (proto: ApiMsgEnum, data: any, view: DataView, index: number) => {
  view.setUint8(index++, data.type)
  view.setUint8(index++, data.owner)
  view.setFloat32(index, data.position.x)
  index += 4
  view.setFloat32(index, data.position.y)
  index += 4
  view.setFloat32(index, data.direction.x)
  index += 4
  view.setFloat32(index, data.direction.y)
  index += 4
}

export const encdoeTimePast = (proto: ApiMsgEnum, data: any, view: DataView, index: number) => {
  view.setUint8(index++, data.type)
  view.setFloat32(index, data.dt)
  index += 4
}

export const binaryEncode = (proto: ApiMsgEnum, data: any): DataView => {
  if (proto === ApiMsgEnum.MsgClientSync) {
    if (data.type === InputTypeEnum.ActorMove) {
      let index = 0
      const ab = new ArrayBuffer(3 + 12)
      const view = new DataView(ab)
      view.setUint8(index++, proto)
      encodeActorMove(proto, data, view, index)
      return view
    } else if (data.type === InputTypeEnum.WeaponShoot) {
      let index = 0
      const ab = new ArrayBuffer(3 + 16)
      const view = new DataView(ab)
      view.setUint8(index++, proto)
      encodeWeaponShoot(proto, data, view, index)
      return view
    } else {
      let index = 0
      const ab = new ArrayBuffer(2 + 4)
      const view = new DataView(ab)
      view.setUint8(index++, proto)
      encdoeTimePast(proto, data, view, index)
      return view
    }
  } else if (proto === ApiMsgEnum.MsgServerSync) {
    let total = 0
    for (let i = 0; i < data.length; i++) {
      const item = data[i];
      if (item.type === InputTypeEnum.ActorMove) {
        total += 14
      } else if (item.type === InputTypeEnum.WeaponShoot) {
        total += 18
      } else {
        total += 5
      }
    }
    const ab = new ArrayBuffer(1 + 1 + total)
    const view = new DataView(ab)
    let index = 0
    view.setUint8(index++, proto)
    view.setUint8(index++, data.length)
    for (let i = 0; i < data.length; i++) {
      const item = data[i];
      if (item.type === InputTypeEnum.ActorMove) {
        encodeActorMove(proto, item, view, index)
        index += 14
      } else if (item.type === InputTypeEnum.WeaponShoot) {
        encodeWeaponShoot(proto, item, view, index)
        index += 18
      } else {
        encdoeTimePast(proto, item, view, index)
        index += 5
      }
    }

    return view
  } else {
    let index = 0
    const str = JSON.stringify(data)
    const ta = strencode(str)
    const ab = new ArrayBuffer(ta.length + 1)
    const view = new DataView(ab)
    view.setUint8(index++, proto)
    for (let i = 0; i < ta.length; i++) {
      view.setUint8(index++, ta[i])
    }
    return view
  }
}

const decodeActorMove = (view: DataView, index: number) => {
  const id = view.getUint8(index++)
  const directionX = view.getFloat32(index)
  index += 4
  const directionY = view.getFloat32(index)
  index += 4
  const dt = view.getFloat32(index)
  index += 4
  const msg = {
    name: ApiMsgEnum.MsgClientSync,
    data: {
      type: InputTypeEnum.ActorMove,
      id,
      direction: {
        x: directionX,
        y: directionY,
      },
      dt
    }
  }

  return msg
}

const decodeWeaponShoot = (view: DataView, index: number) => {
  const owner = view.getUint8(index++)
  const positionX = view.getFloat32(index)
  index += 4
  const positionY = view.getFloat32(index)
  index += 4
  const directionX = view.getFloat32(index)
  index += 4
  const directionY = view.getFloat32(index)
  index += 4
  const msg = {
    name: ApiMsgEnum.MsgClientSync,
    data: {
      type: InputTypeEnum.WeaponShoot,
      owner,
      position: {
        x: positionX,
        y: positionY,
      },
      direction: {
        x: directionX,
        y: directionY,
      },
    }
  }

  return msg
}

const decodeTimePast = (view: DataView, index: number) => {
  const dt = view.getFloat32(index)
  index += 4
  const msg = {
    name: ApiMsgEnum.MsgClientSync,
    data: {
      type: InputTypeEnum.TimePast,
      dt,
    }
  }
  return msg
}

export const binaryDecode = (buffer: ArrayBuffer) => {
  let index = 0
  const view = new DataView(buffer)
  const proto = view.getUint8(index++)

  if (proto === ApiMsgEnum.MsgClientSync) {
    const inputType = view.getUint8(index++)
    if (inputType === InputTypeEnum.ActorMove) {
      return decodeActorMove(view, index)
    } else if (inputType === InputTypeEnum.WeaponShoot) {
      return decodeWeaponShoot(view, index)
    } else {
      return decodeTimePast(view, index)
    }
  } else if (proto === ApiMsgEnum.MsgServerSync) {
    const len = view.getUint8(index++)
    const res = []
    for (let i = 0; i < len; i++) {
      const inputType = view.getUint8(index++)

      if (inputType === InputTypeEnum.ActorMove) {
        res.push(decodeActorMove(view, index).data)
        index += 13
      } else if (inputType === InputTypeEnum.WeaponShoot) {
        res.push(decodeWeaponShoot(view, index).data)
        index += 17
      } else {
        res.push(decodeTimePast(view, index).data)
        index += 4
      }
    }
    return {
      name: ApiMsgEnum.MsgServerSync,
      data: res
    }
  } else {
    return {
      name: proto,
      data: JSON.parse(strdecode(new Uint8Array(buffer.slice(1))))
    }
  }
}