@edsilv/ami.js/src/widgets/widgets.freehand.js

<p align="center"> <img src="https://user-images.githubusercontent.com/214063/46479857-4cd66e80-c7f0-11e8-9585-5748409c9490.png" width="60%"> </p>

import { widgetsBase } from './widgets.base';
import { widgetsHandle as widgetsHandleFactory } from './widgets.handle';
import CoreUtils from '../core/core.utils';

/**
 * @module widgets/freehand
 */
const widgetsFreehand = (three = window.THREE) => {
  if (three === undefined || three.Object3D === undefined) {
    return null;
  }

  const Constructor = widgetsBase(three);
  return class extends Constructor {
    constructor(targetMesh, controls, params = {}) {
      super(targetMesh, controls, params);

      this._widgetType = 'Freehand';

      // incoming parameters (optional: frameIndex, worldPosition)
      this._stack = params.stack; // required
      this._calibrationFactor = params.calibrationFactor || null;

      // outgoing values
      this._area = null;
      this._units =
        !this._calibrationFactor && !params.stack.frame[params.frameIndex].pixelSpacing
          ? 'units'
          : 'cm²';

      this._initialized = false; // set to true onEnd if number of handles > 2
      this._moving = false;
      this._domHovered = false;

      // mesh stuff
      this._material = null;
      this._geometry = null;
      this._mesh = null;

      // dom stuff
      this._lines = [];
      this._label = null;

      // add handles
      this._handles = [];
      const WidgetsHandle = widgetsHandleFactory(three);

      let handle = new WidgetsHandle(targetMesh, controls, params);
      this.add(handle);
      this._handles.push(handle);

      this._moveHandle = new WidgetsHandle(targetMesh, controls, params);
      this.add(this._moveHandle);
      this._moveHandle.hide();

      this.onMove = this.onMove.bind(this);
      this.onHover = this.onHover.bind(this);

      this.create();

      this.addEventListeners();
    }

    addEventListeners() {
      this._container.addEventListener('wheel', this.onMove);

      this._label.addEventListener('mouseenter', this.onHover);
      this._label.addEventListener('mouseleave', this.onHover);
    }

    removeEventListeners() {
      this._container.removeEventListener('wheel', this.onMove);

      this._label.removeEventListener('mouseenter', this.onHover);
      this._label.removeEventListener('mouseleave', this.onHover);
    }

    onHover(evt) {
      if (evt) {
        this.hoverDom(evt);
      }

      this.hoverMesh();

      let hovered = false;

      this._handles.forEach(elem => (hovered = hovered || elem.hovered));

      this._hovered = hovered || this._domHovered;
      this._container.style.cursor = this._hovered ? 'pointer' : 'default';
    }

    hoverMesh() {
      // check raycast intersection, if we want to hover on mesh instead of just css
    }

    hoverDom(evt) {
      this._domHovered = evt.type === 'mouseenter';
    }

    onStart(evt) {
      let active = false;

      this._moveHandle.onMove(evt, true);
      this._handles.forEach(elem => {
        elem.onStart(evt);
        active = active || elem.active;
      });

      this._active = active || this._domHovered;

      if (this._domHovered && this._initialized) {
        this._moving = true;
        this._controls.enabled = false;
      }

      this.update();
    }

    onMove(evt) {
      let hovered = false;

      if (this.active) {
        this._dragged = true;

        if (!this._initialized) {
          this._handles[this._handles.length - 1].hovered = false;
          this._handles[this._handles.length - 1].active = false;
          this._handles[this._handles.length - 1].tracking = false;

          const WidgetsHandle = widgetsHandleFactory(three);
          let handle = new WidgetsHandle(this._targetMesh, this._controls, this._params);

          handle.hovered = true;
          handle.active = true;
          handle.tracking = true;
          this.add(handle);
          this._handles.push(handle);

          this.createLine();
        } else {
          const prevPosition = this._moveHandle.worldPosition.clone();

          this._moveHandle.onMove(evt, true);
          if (this._mesh) {
            this.remove(this._mesh);
          }
          this.updateDOMContent(true);
          if (this._moving) {
            this._handles.forEach(handle => {
              handle.worldPosition.add(this._moveHandle.worldPosition.clone().sub(prevPosition));
            });
          }
        }
      }

      this._handles.forEach(elem => {
        elem.onMove(evt);
        hovered = hovered || elem.hovered;
      });

      this._hovered = hovered || this._domHovered;
      this._container.style.cursor = this._hovered ? 'pointer' : 'default';

      if (this.active && this._handles.length > 2) {
        this.pushPopHandle();
      }

      this.update();
    }

    onEnd() {
      if (this._handles.length < 3) {
        return;
      }

      let active = false;

      this._handles.slice(0, -1).forEach(elem => {
        elem.onEnd();
        active = active || elem.active;
      });

      // Last Handle
      if (this._dragged || !this._handles[this._handles.length - 1].tracking) {
        this._handles[this._handles.length - 1].tracking = false;
        this._handles[this._handles.length - 1].onEnd();
      } else {
        this._handles[this._handles.length - 1].tracking = false;
      }

      if (this._lines.length < this._handles.length) {
        this.createLine();
      }

      if (this._dragged || !this._initialized) {
        this.updateMesh();
        this.updateDOMContent();
      }

      if (!this._dragged && this._active) {
        this._selected = !this._selected; // change state if there was no dragging
        this._handles.forEach(elem => (elem.selected = this._selected));
      }
      this._active = active || this._handles[this._handles.length - 1].active;
      this._dragged = false;
      this._moving = false;
      this._initialized = true;

      this.update();
    }

    create() {
      this.createMaterial();
      this.createDOM();
    }

    createMaterial() {
      this._material = new three.MeshBasicMaterial({ side: three.DoubleSide });
      this._material.transparent = true;
      this._material.opacity = 0.2;
    }

    createDOM() {
      this._label = document.createElement('div');
      this._label.className = 'widgets-label';

      // measurements
      const measurementsContainer = document.createElement('div');
      // Mean / SD
      let meanSDContainer = document.createElement('div');
      meanSDContainer.className = 'mean-sd';
      measurementsContainer.appendChild(meanSDContainer);
      // Max / Min
      let maxMinContainer = document.createElement('div');
      maxMinContainer.className = 'max-min';
      measurementsContainer.appendChild(maxMinContainer);
      // Area
      let areaContainer = document.createElement('div');
      areaContainer.className = 'area';
      measurementsContainer.appendChild(areaContainer);

      this._label.appendChild(measurementsContainer);

      this._container.appendChild(this._label);

      this.updateDOMColor();
    }

    createLine() {
      const line = document.createElement('div');

      line.className = 'widgets-line';
      line.addEventListener('mouseenter', this.onHover);
      line.addEventListener('mouseleave', this.onHover);
      this._lines.push(line);
      this._container.appendChild(line);
    }

    hideDOM() {
      this._handles.forEach(elem => elem.hideDOM());

      this._lines.forEach(elem => (elem.style.display = 'none'));
      this._label.style.display = 'none';
    }

    showDOM() {
      this._handles.forEach(elem => elem.showDOM());

      this._lines.forEach(elem => (elem.style.display = ''));
      this._label.style.display = '';
    }

    update() {
      this.updateColor();

      // update handles
      this._handles.forEach(elem => elem.update());

      // mesh stuff
      this.updateMeshColor();
      this.updateMeshPosition();

      // DOM stuff
      this.updateDOMColor();
      this.updateDOMPosition();
    }

    updateMesh() {
      if (this._mesh) {
        this.remove(this._mesh);
      }

      let points = [];

      this._handles.forEach(elem => points.push(elem.worldPosition));

      let center = CoreUtils.centerOfMass(points);
      // direction from first point to center
      let referenceDirection = new three.Vector3().subVectors(points[0], center).normalize();
      let direction = new three.Vector3().crossVectors(
        new three.Vector3().subVectors(points[0], center), // side 1
        new three.Vector3().subVectors(points[1], center) // side 2
      );
      let base = new three.Vector3().crossVectors(referenceDirection, direction).normalize();
      let orderedpoints = [];

      // other lines // if inter, return location + angle
      for (let j = 0; j < points.length; j++) {
        let point = new three.Vector3(points[j].x, points[j].y, points[j].z);
        point.direction = new three.Vector3().subVectors(points[j], center).normalize();

        let x = referenceDirection.dot(point.direction);
        let y = base.dot(point.direction);
        point.xy = { x, y };
        point.angle = Math.atan2(y, x) * (180 / Math.PI);

        orderedpoints.push(point);
      }

      // override to catch console.warn "THREE.ShapeUtils: Unable to triangulate polygon! in triangulate()"
      this._shapeWarn = false;
      const oldWarn = console.warn;
      console.warn = function(...rest) {
        if (rest[0] === 'three.ShapeUtils: Unable to triangulate polygon! in triangulate()') {
          this._shapeWarn = true;
        }
        return oldWarn.apply(console, rest);
      }.bind(this);

      // create the shape
      let shape = new three.Shape();
      // move to first point!
      shape.moveTo(orderedpoints[0].xy.x, orderedpoints[0].xy.y);

      // loop through all points!
      for (let l = 1; l < orderedpoints.length; l++) {
        // project each on plane!
        shape.lineTo(orderedpoints[l].xy.x, orderedpoints[l].xy.y);
      }

      // close the shape!
      shape.lineTo(orderedpoints[0].xy.x, orderedpoints[0].xy.y);

      this._geometry = new three.ShapeGeometry(shape);

      console.warn = oldWarn;

      this._geometry.vertices = orderedpoints;
      this._geometry.verticesNeedUpdate = true;
      this._geometry.elementsNeedUpdate = true;

      this.updateMeshColor();

      this._mesh = new three.Mesh(this._geometry, this._material);
      this._mesh.visible = true;
      this.add(this._mesh);
    }

    updateMeshColor() {
      if (this._material) {
        this._material.color.set(this._color);
      }
    }

    updateMeshPosition() {
      if (this._geometry) {
        this._geometry.verticesNeedUpdate = true;
      }
    }

    isPointOnLine(pointA, pointB, pointToCheck) {
      let c = new three.Vector3();
      c.crossVectors(pointA.clone().sub(pointToCheck), pointB.clone().sub(pointToCheck));
      return !c.length();
    }

    pushPopHandle() {
      let handle0 = this._handles[this._handles.length - 3];
      let handle1 = this._handles[this._handles.length - 2];
      let newhandle = this._handles[this._handles.length - 1];

      let isOnLine = this.isPointOnLine(
        handle0.worldPosition,
        handle1.worldPosition,
        newhandle.worldPosition
      );

      if (isOnLine || handle0.screenPosition.distanceTo(newhandle.screenPosition) < 25) {
        this.remove(handle1);
        handle1.free();

        this._handles[this._handles.length - 2] = newhandle;
        this._handles.pop();

        this._container.removeChild(this._lines.pop());
      }

      return isOnLine;
    }

    updateDOMColor() {
      if (this._handles.length >= 2) {
        this._lines.forEach(elem => (elem.style.backgroundColor = this._color));
      }
      this._label.style.borderColor = this._color;
    }

    updateDOMContent(clear) {
      const meanSDContainer = this._label.querySelector('.mean-sd');
      const maxMinContainer = this._label.querySelector('.max-min');
      const areaContainer = this._label.querySelector('.area');

      if (clear) {
        meanSDContainer.innerHTML = '';
        maxMinContainer.innerHTML = '';
        areaContainer.innerHTML = '';

        return;
      }

      const regions = this._stack.frame[this._params.frameIndex].ultrasoundRegions || [];

      this._area = CoreUtils.getGeometryArea(this._geometry); // this.getArea result is changed on dragging
      if (this._calibrationFactor) {
        this._area *= Math.pow(this._calibrationFactor, 2);
      } else if (regions && regions.length > 0 && this._stack.lps2IJK) {
        let same = true;
        let cRegion;
        let pRegion;

        this._handles.forEach(elem => {
          cRegion = this.getRegionByXY(
            regions,
            CoreUtils.worldToData(this._stack.lps2IJK, elem.worldPosition)
          );
          if (
            cRegion === null ||
            regions[cRegion].unitsX !== 'cm' ||
            (pRegion !== undefined && pRegion !== cRegion)
          ) {
            same = false;
          }
          pRegion = cRegion;
        });

        if (same) {
          this._area *= Math.pow(regions[cRegion].deltaX, 2);
          this._units = 'cm²';
        } else if (this._stack.frame[this._params.frameIndex].pixelSpacing) {
          this._area /= 100;
          this._units = 'cm²';
        } else {
          this._units = 'units';
        }
      } else if (this._units === 'cm²') {
        this._area /= 100;
      }

      let title =
        this._units === 'units' ? 'Calibration is required to display the area in cm². ' : '';

      if (this._shapeWarn) {
        title += 'Values may be incorrect due to triangulation error.';
      }
      if (title !== '' && !this._label.hasAttribute('title')) {
        this._label.setAttribute('title', title);
        this._label.style.color = this._colors.error;
      } else if (title === '' && this._label.hasAttribute('title')) {
        this._label.removeAttribute('title');
        this._label.style.color = this._colors.text;
      }

      const roi = CoreUtils.getRoI(this._mesh, this._camera, this._stack);

      if (roi !== null) {
        meanSDContainer.innerHTML = `Mean: ${roi.mean.toFixed(1)} / SD: ${roi.sd.toFixed(1)}`;
        maxMinContainer.innerHTML = `Max: ${roi.max.toFixed()} / Min: ${roi.min.toFixed()}`;
      } else {
        meanSDContainer.innerHTML = '';
        maxMinContainer.innerHTML = '';
      }
      areaContainer.innerHTML = `Area: ${this._area.toFixed(2)} ${this._units}`;
    }

    updateDOMPosition() {
      if (this._handles.length < 2) {
        return;
      }
      // update lines and get coordinates of lowest handle
      let labelPosition = null;

      this._lines.forEach((elem, ind) => {
        const lineData = this.getLineData(
          this._handles[ind].screenPosition,
          this._handles[ind + 1 === this._handles.length ? 0 : ind + 1].screenPosition
        );

        elem.style.transform = `translate3D(${lineData.transformX}px, ${lineData.transformY}px, 0)
                rotate(${lineData.transformAngle}rad)`;
        elem.style.width = lineData.length + 'px';

        if (labelPosition === null || labelPosition.y < this._handles[ind].screenPosition.y) {
          labelPosition = this._handles[ind].screenPosition.clone();
        }
      });

      if (!this._initialized) {
        return;
      }

      // update label
      labelPosition.y += 15 + this._label.offsetHeight / 2;
      labelPosition = this.adjustLabelTransform(this._label, labelPosition);

      this._label.style.transform = `translate3D(${labelPosition.x}px, ${labelPosition.y}px, 0)`;
    }

    free() {
      this.removeEventListeners();

      this._handles.forEach(h => {
        this.remove(h);
        h.free();
      });
      this._handles = [];

      this.remove(this._moveHandle);
      this._moveHandle.free();
      this._moveHandle = null;

      this._lines.forEach(elem => {
        elem.removeEventListener('mouseenter', this.onHover);
        elem.removeEventListener('mouseleave', this.onHover);
        this._container.removeChild(elem);
      });
      this._lines = [];
      this._container.removeChild(this._label);

      // mesh, geometry, material
      if (this._mesh) {
        this.remove(this._mesh);
        this._mesh.geometry.dispose();
        this._mesh.geometry = null;
        this._mesh.material.dispose();
        this._mesh.material = null;
        this._mesh = null;
      }
      if (this._geometry) {
        this._geometry.dispose();
        this._geometry = null;
      }
      this._material.vertexShader = null;
      this._material.fragmentShader = null;
      this._material.uniforms = null;
      this._material.dispose();
      this._material = null;

      this._stack = null;

      super.free();
    }

    getMeasurements() {
      return {
        area: this._area,
        units: this._units,
      };
    }

    get targetMesh() {
      return this._targetMesh;
    }

    set targetMesh(targetMesh) {
      this._targetMesh = targetMesh;
      this._handles.forEach(elem => (elem.targetMesh = targetMesh));
      this._moveHandle.targetMesh = targetMesh;
      this.update();
    }

    get worldPosition() {
      return this._worldPosition;
    }

    set worldPosition(worldPosition) {
      this._handles.forEach(elem => elem._worldPosition.copy(worldPosition));
      this._worldPosition.copy(worldPosition);
      this.update();
    }

    get calibrationFactor() {
      return this._calibrationFactor;
    }

    set calibrationFactor(calibrationFactor) {
      this._calibrationFactor = calibrationFactor;
      this._units = 'cm²';
      this.update();
    }
  };
};

export { widgetsFreehand };
export default widgetsFreehand();