constructor()

in modules/core/src/viewports/web-mercator-viewport.js [46:134]

• 62 lines of code
• 6 McCabe index (conditional complexity)

  constructor(opts = {}) {
    const {
      latitude = 0,
      longitude = 0,
      zoom = 11,
      pitch = 0,
      bearing = 0,
      nearZMultiplier = 0.1,
      farZMultiplier = 1.01,
      orthographic = false,

      repeat = false,
      worldOffset = 0
    } = opts;

    let {width, height, altitude = 1.5} = opts;
    const scale = Math.pow(2, zoom);

    // Silently allow apps to send in 0,0 to facilitate isomorphic render etc
    width = width || 1;
    height = height || 1;

    // Altitude - prevent division by 0
    // TODO - just throw an Error instead?
    altitude = Math.max(0.75, altitude);

    const {fov, aspect, focalDistance, near, far} = getProjectionParameters({
      width,
      height,
      pitch,
      altitude,
      nearZMultiplier,
      farZMultiplier
    });

    // The uncentered matrix allows us two move the center addition to the
    // shader (cheap) which gives a coordinate system that has its center in
    // the layer's center position. This makes rotations and other modelMatrx
    // transforms much more useful.
    let viewMatrixUncentered = getViewMatrix({
      height,
      pitch,
      bearing,
      scale,
      altitude
    });

    if (worldOffset) {
      const viewOffset = new Matrix4().translate([512 * worldOffset, 0, 0]);
      viewMatrixUncentered = viewOffset.multiplyLeft(viewMatrixUncentered);
    }

    const viewportOpts = Object.assign({}, opts, {
      // x, y,
      width,
      height,

      // view matrix
      viewMatrix: viewMatrixUncentered,
      longitude,
      latitude,
      zoom,

      // projection matrix parameters
      orthographic,
      fovyRadians: fov,
      aspect,
      // TODO Viewport is already carefully set up to "focus" on ground, so can't use focal distance
      focalDistance: orthographic ? focalDistance : 1,
      near,
      far
    });

    super(viewportOpts);

    // Save parameters
    this.latitude = latitude;
    this.longitude = longitude;
    this.zoom = zoom;
    this.pitch = pitch;
    this.bearing = bearing;
    this.altitude = altitude;

    this.orthographic = orthographic;

    this._subViewports = repeat ? [] : null;

    Object.freeze(this);
  }