homemanager-fe/src/modules/house-planner/canvas.ts

import { HousePlannerCanvasGrid } from './grid';
import { BezierSegment, Layer, Line, LineSegment, Vec2 } from './interfaces';
import { HousePlannerCanvasTools } from './tools';
import {
  rad2deg,
  vec2Add,
  vec2AngleFromOrigin,
  vec2Distance,
  vec2DivideScalar,
  vec2PointFromAngle,
} from './utils';

export class HousePlannerCanvas {
  public ctx!: CanvasRenderingContext2D;
  public layers: Layer[] = [];
  public tools = new HousePlannerCanvasTools(this);
  public grid = new HousePlannerCanvasGrid(this, 8);

  constructor(public canvas: HTMLCanvasElement) {
    this.ctx = this.canvas.getContext('2d')!;
    this.setupEvents();
  }

  get width() {
    return this.canvas.width;
  }

  get height() {
    return this.canvas.height;
  }

  addLayer(layer: Layer) {
    this.layers.push(layer);
    this.draw();
  }

  cleanUp() {
    this.tools.cleanUp();
    window.removeEventListener('keyup', this.boundKeyUpEvent);
    window.removeEventListener('keydown', this.boundKeyDownEvent);
  }

  draw() {
    this.ctx.clearRect(0, 0, this.width, this.height);
    this.grid.draw();
    this.tools.drawHighlights();
    for (const layer of this.layers) {
      if (!layer.visible) continue;
      if (!layer.contents?.length) continue;
      this.drawLayer(layer);
    }
    this.tools.drawControls();
  }

  makeBezier(segment: BezierSegment, path: Path2D) {
    const bezier = segment as BezierSegment;
    const [cp1x, cp1y] = bezier.startControl;
    const [cp2x, cp2y] = bezier.endControl;
    const [x, y] = bezier.end;
    path.bezierCurveTo(cp1x, cp1y, cp2x, cp2y, x, y);
  }

  makeLinePath(line: Line) {
    const path = new Path2D();
    const [firstSegment, ...segments] = line.segments;
    // first segment must have a starting point
    if (!firstSegment.start) return path;
    path.moveTo(...firstSegment.start);

    if (line.type === 'curve') {
      const lineLength = vec2Distance(firstSegment.start, firstSegment.end);
      const lineAngle = vec2AngleFromOrigin(
        firstSegment.end,
        firstSegment.start!
      );
      const ninety = lineAngle + Math.PI / 2;
      path.moveTo(...firstSegment.end);
      path.arc(
        firstSegment.start[0],
        firstSegment.start[1],
        lineLength,
        lineAngle,
        ninety
      );
      path.lineTo(...firstSegment.start);
    } else if ((firstSegment as BezierSegment).startControl) {
      this.makeBezier(firstSegment as BezierSegment, path);
    } else {
      path.lineTo(...firstSegment.end);
    }

    for (const segment of segments) {
      if ((segment as BezierSegment).startControl) {
        this.makeBezier(segment as BezierSegment, path);
        continue;
      }

      path.lineTo(...segment.end);
    }
    if (line.closed && line.type !== 'curve') {
      path.closePath();
    }
    return path;
  }

  setupLine(line: Line, overBounds = 0, overrideColor?: string) {
    if (line.lineDash) {
      this.ctx.setLineDash(line.lineDash);
    }

    this.ctx.strokeStyle = overrideColor || line.color || '#000';
    this.ctx.lineWidth = line.width + overBounds;

    if (line.lineCap) {
      this.ctx.lineCap = line.lineCap;
    }
  }

  isOnLine(line: Line, x: number, y: number, selectError = 16) {
    let path = line.render || this.makeLinePath(line);
    this.setupLine(line, selectError);
    return this.ctx.isPointInStroke(path, x, y);
  }

  isOnSegment(
    line: Line,
    segment: LineSegment,
    lastPoint: Vec2,
    x: number,
    y: number,
    selectError = 16
  ) {
    const fakePath = this.makeLinePath({
      ...line,
      closed: false,
      segments: [{ ...segment, start: lastPoint }],
    });
    this.setupLine(line, selectError);
    return this.ctx.isPointInStroke(fakePath, x, y);
  }

  private keyDownEvent(e: KeyboardEvent) {
    if (e.target !== document.body && e.target != null) return;
    e.preventDefault();
    this.tools.onKeyDown(e);
  }
  private boundKeyDownEvent = this.keyDownEvent.bind(this);
  private keyUpEvent(e: KeyboardEvent) {
    if (e.target !== document.body && e.target != null) return;
    e.preventDefault();
    this.tools.onKeyUp(e);
  }
  private boundKeyUpEvent = this.keyUpEvent.bind(this);

  private setupEvents() {
    window.addEventListener('keyup', this.boundKeyUpEvent);
    window.addEventListener('keydown', this.boundKeyDownEvent);

    this.canvas.addEventListener('mousemove', (e) => this.tools.onMouseMove(e));
    this.canvas.addEventListener('mousedown', (e) => this.tools.onMouseDown(e));
    this.canvas.addEventListener('mouseup', (e) => this.tools.onMouseUp(e));

    this.canvas.addEventListener('touchmove', (e) => this.tools.onTouchMove(e));
    this.canvas.addEventListener('touchstart', (e) =>
      this.tools.onTouchStart(e)
    );
    this.canvas.addEventListener('touchend', (e) => this.tools.onTouchEnd(e));
    this.canvas.addEventListener('wheel', (e) => this.tools.onMouseWheel(e));

    this.canvas.addEventListener('pointerleave', () =>
      this.tools.onPointerLeave()
    );
  }

  private drawRoomText(line: Line) {
    const centerPoint = vec2DivideScalar(
      line.segments.reduce<Vec2 | null>((prev, curr) => {
        if (!prev) {
          if (curr.start) {
            return vec2Add(curr.start, curr.end);
          }
          return curr.end;
        }

        let preadd = vec2Add(prev, curr.end);
        if (curr.start) {
          preadd = vec2Add(curr.start, preadd);
        }
        return preadd;
      }, null) as Vec2,
      line.segments.length + 1
    );
    this.ctx.font = '16px Arial';
    this.ctx.fillStyle = line.color;
    const { width } = this.ctx.measureText(line.name);
    this.ctx.fillText(
      line.name,
      centerPoint[0] - width / 2,
      centerPoint[1] - 8
    );
  }

  private drawLine(line: Line) {
    const path = this.makeLinePath(line);
    line.render = path;
    this.setupLine(line);
    this.ctx.stroke(path);
    if (line.type === 'room') {
      this.drawRoomText(line);
    }
  }

  private drawLayer(layer: Layer) {
    for (const item of layer.contents) {
      if (!item.visible) continue;
      const line = item as Line;
      if (line.segments) {
        this.drawLine(line);
        continue;
      }
    }
  }
}