y2024_defense/www/field_handler.ts

import {ByteBuffer} from 'flatbuffers'
import {ClientStatistics} from '../../aos/network/message_bridge_client_generated'
import {ServerStatistics, State as ConnectionState} from '../../aos/network/message_bridge_server_generated'
import {Connection} from '../../aos/network/www/proxy'
import {ZeroingError} from '../../frc971/control_loops/control_loops_generated'
import {Status as DrivetrainStatus} from '../../frc971/control_loops/drivetrain/drivetrain_status_generated'
import {LocalizerOutput} from '../../frc971/control_loops/drivetrain/localization/localizer_output_generated'

import {FIELD_LENGTH, FIELD_WIDTH, FT_TO_M, IN_TO_M} from './constants';

// (0,0) is field center, +X is toward red DS
const FIELD_SIDE_Y = FIELD_WIDTH / 2;
const FIELD_EDGE_X = FIELD_LENGTH / 2;

const ROBOT_WIDTH = 25 * IN_TO_M;
const ROBOT_LENGTH = 32 * IN_TO_M;

const PI_COLORS = ['#ff00ff', '#ffff00', '#00ffff', '#ffa500'];
const PIS = ['pi1', 'pi2', 'pi3', 'pi4'];

export class FieldHandler {
  private canvas = document.createElement('canvas');
  private localizerOutput: LocalizerOutput|null = null;
  private drivetrainStatus: DrivetrainStatus|null = null;

  private x: HTMLElement = (document.getElementById('x') as HTMLElement);
  private y: HTMLElement = (document.getElementById('y') as HTMLElement);
  private theta: HTMLElement =
      (document.getElementById('theta') as HTMLElement);
  // HTML elements for rejection reasons for individual pis. Indices
  // corresponding to RejectionReason enum values will be for those reasons. The
  // final row will account for images rejected by the aprilrobotics detector
  // instead of the localizer.
  private messageBridgeDiv: HTMLElement =
      (document.getElementById('message_bridge_status') as HTMLElement);
  private clientStatuses = new Map<string, HTMLElement>();
  private serverStatuses = new Map<string, HTMLElement>();
  private fieldImage: HTMLImageElement = new Image();
  
  constructor(private readonly connection: Connection) {
    (document.getElementById('field') as HTMLElement).appendChild(this.canvas);

    this.fieldImage.src = '2023.png';

    this.connection.addConfigHandler(() => {
      // Visualization message is reliable so that we can see *all* the vision
      // matches.
      this.connection.addHandler(
          '/drivetrain', 'frc971.control_loops.drivetrain.Status', (data) => {
            this.handleDrivetrainStatus(data);
          });
      this.connection.addHandler(
          '/localizer', 'frc971.controls.LocalizerOutput', (data) => {
            this.handleLocalizerOutput(data);
          });
      this.connection.addHandler(
          '/aos', 'aos.message_bridge.ServerStatistics',
          (data) => {this.handleServerStatistics(data)});
      this.connection.addHandler(
          '/aos', 'aos.message_bridge.ClientStatistics',
          (data) => {this.handleClientStatistics(data)});
    });
  }

  private handleLocalizerOutput(data: Uint8Array): void {
    const fbBuffer = new ByteBuffer(data);
    this.localizerOutput = LocalizerOutput.getRootAsLocalizerOutput(fbBuffer);
  }

  private handleDrivetrainStatus(data: Uint8Array): void {
    const fbBuffer = new ByteBuffer(data);
    this.drivetrainStatus = DrivetrainStatus.getRootAsStatus(fbBuffer);
  }

  private populateNodeConnections(nodeName: string): void {
    const row = document.createElement('div');
    this.messageBridgeDiv.appendChild(row);
    const nodeDiv = document.createElement('div');
    nodeDiv.innerHTML = nodeName;
    row.appendChild(nodeDiv);
    const clientDiv = document.createElement('div');
    clientDiv.innerHTML = 'N/A';
    row.appendChild(clientDiv);
    const serverDiv = document.createElement('div');
    serverDiv.innerHTML = 'N/A';
    row.appendChild(serverDiv);
    this.serverStatuses.set(nodeName, serverDiv);
    this.clientStatuses.set(nodeName, clientDiv);
  }

  private setCurrentNodeState(element: HTMLElement, state: ConnectionState):
      void {
    if (state === ConnectionState.CONNECTED) {
      element.innerHTML = ConnectionState[state];
      element.classList.remove('faulted');
      element.classList.add('connected');
    } else {
      element.innerHTML = ConnectionState[state];
      element.classList.remove('connected');
      element.classList.add('faulted');
    }
  }

  private handleServerStatistics(data: Uint8Array): void {
    const fbBuffer = new ByteBuffer(data);
    const serverStatistics =
        ServerStatistics.getRootAsServerStatistics(fbBuffer);

    for (let ii = 0; ii < serverStatistics.connectionsLength(); ++ii) {
      const connection = serverStatistics.connections(ii);
      const nodeName = connection.node().name();
      if (!this.serverStatuses.has(nodeName)) {
        this.populateNodeConnections(nodeName);
      }
      this.setCurrentNodeState(
          this.serverStatuses.get(nodeName), connection.state());
    }
  }

  private handleClientStatistics(data: Uint8Array): void {
    const fbBuffer = new ByteBuffer(data);
    const clientStatistics =
        ClientStatistics.getRootAsClientStatistics(fbBuffer);

    for (let ii = 0; ii < clientStatistics.connectionsLength(); ++ii) {
      const connection = clientStatistics.connections(ii);
      const nodeName = connection.node().name();
      if (!this.clientStatuses.has(nodeName)) {
        this.populateNodeConnections(nodeName);
      }
      this.setCurrentNodeState(
          this.clientStatuses.get(nodeName), connection.state());
    }
  }

  setZeroing(div: HTMLElement): void {
    div.innerHTML = 'zeroing';
    div.classList.remove('faulted');
    div.classList.add('zeroing');
    div.classList.remove('near');
  }

  setValue(div: HTMLElement, val: number): void {
    div.innerHTML = val.toFixed(4);
    div.classList.remove('faulted');
    div.classList.remove('zeroing');
    div.classList.remove('near');
  }

  drawField(): void {
    const ctx = this.canvas.getContext('2d');
    ctx.save();
    ctx.scale(1.0, -1.0);
    ctx.drawImage(
        this.fieldImage, 0, 0, this.fieldImage.width, this.fieldImage.height,
        -FIELD_EDGE_X, -FIELD_SIDE_Y, FIELD_LENGTH, FIELD_WIDTH);
    ctx.restore();
  }

  drawCamera(x: number, y: number, theta: number, color: string = 'blue'):
      void {
    const ctx = this.canvas.getContext('2d');
    ctx.save();
    ctx.translate(x, y);
    ctx.rotate(theta);
    ctx.strokeStyle = color;
    ctx.beginPath();
    ctx.moveTo(0.5, 0.5);
    ctx.lineTo(0, 0);
    ctx.lineTo(0.5, -0.5);
    ctx.stroke();
    ctx.beginPath();
    ctx.arc(0, 0, 0.25, -Math.PI / 4, Math.PI / 4);
    ctx.stroke();
    ctx.restore();
  }

  drawRobot(
      x: number, y: number, theta: number, color: string = 'blue',
      dashed: boolean = false): void {
    const ctx = this.canvas.getContext('2d');
    ctx.save();
    ctx.translate(x, y);
    ctx.rotate(theta);
    ctx.strokeStyle = color;
    ctx.lineWidth = ROBOT_WIDTH / 10.0;
    if (dashed) {
      ctx.setLineDash([0.05, 0.05]);
    } else {
      // Empty array = solid line.
      ctx.setLineDash([]);
    }
    ctx.rect(-ROBOT_LENGTH / 2, -ROBOT_WIDTH / 2, ROBOT_LENGTH, ROBOT_WIDTH);
    ctx.stroke();

    // Draw line indicating which direction is forwards on the robot.
    ctx.beginPath();
    ctx.moveTo(0, 0);
    ctx.lineTo(ROBOT_LENGTH / 2.0, 0);
    ctx.stroke();

    ctx.restore();
  }

  draw(): void {
    this.reset();
    this.drawField();

    // Draw the matches with debugging information from the localizer.
    const now = Date.now() / 1000.0;

    if (this.drivetrainStatus && this.drivetrainStatus.trajectoryLogging()) {
      this.drawRobot(
          this.drivetrainStatus.trajectoryLogging().x(),
          this.drivetrainStatus.trajectoryLogging().y(),
          this.drivetrainStatus.trajectoryLogging().theta(), '#000000FF',
          false);
    }

    if (this.localizerOutput) {
      if (!this.localizerOutput.zeroed()) {
        this.setZeroing(this.x);
        this.setZeroing(this.y);
        this.setZeroing(this.theta);
      } else {
        this.setValue(this.x, this.localizerOutput.x());
        this.setValue(this.y, this.localizerOutput.y());
        this.setValue(this.theta, this.localizerOutput.theta());
      }

      this.drawRobot(
          this.localizerOutput.x(), this.localizerOutput.y(),
          this.localizerOutput.theta());
    }


    window.requestAnimationFrame(() => this.draw());
  }

  reset(): void {
    const ctx = this.canvas.getContext('2d');
    ctx.setTransform(1, 0, 0, 1, 0, 0);
    const size = window.innerHeight * 0.9;
    ctx.canvas.height = size;
    const width = size / 2 + 20;
    ctx.canvas.width = width;
    ctx.clearRect(0, 0, size, width);

    // Translate to center of display.
    ctx.translate(width / 2, size / 2);
    // Coordinate system is:
    // x -> forward.
    // y -> to the left.
    ctx.rotate(-Math.PI / 2);
    ctx.scale(1, -1);

    const M_TO_PX = (size - 10) / FIELD_LENGTH;
    ctx.scale(M_TO_PX, M_TO_PX);
    ctx.lineWidth = 1 / M_TO_PX;
  }
}