kepler.gl/src/deckgl-layers/arc-brushing-layer/arc-brushing-layer.js

kepler.gl is a webgl based application to visualize large scale location data in the browser

// Copyright (c) 2018 Uber Technologies, Inc.
//
// Permission is hereby granted, free of charge, to any person obtaining a copy
// of this software and associated documentation files (the "Software"), to deal
// in the Software without restriction, including without limitation the rights
// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
// copies of the Software, and to permit persons to whom the Software is
// furnished to do so, subject to the following conditions:
//
// The above copyright notice and this permission notice shall be included in
// all copies or substantial portions of the Software.
//
// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
// THE SOFTWARE.

import {ArcLayer} from 'deck.gl';
import {editShader} from 'deckgl-layers/layer-utils/shader-utils';

const defaultProps = {
  ...ArcLayer.defaultProps,
  // show arc if source is in brush
  brushSource: true,
  // show arc if target is in brush
  brushTarget: true,
  enableBrushing: true,
  getStrokeWidth: d => d.strokeWidth,
  strokeScale: 1,
  // brush radius in meters
  brushRadius: 100000,
  mousePosition: [0, 0]
};

function addBrushingVsShader(vs) {
  return editShader(
    vs,
    'arc brushing vs',
    'vec2 offset = getExtrusionOffset((next.xy - curr.xy) * indexDir, positions.y);',
    'vec2 offset = brushing_getExtrusionOffset((next.xy - curr.xy) * indexDir, positions.y, project_uViewportSize, instancePositions, instanceWidths);'
  );
}

function addBrushingVs64Shader(vs) {
  return editShader(
    vs,
    'arc brushing vs64',
    'vec2 offset = getExtrusionOffset(next_pos_clipspace.xy - curr_pos_clipspace.xy, positions.y);',
    'vec2 offset = brushing_getExtrusionOffset(next_pos_clipspace.xy - curr_pos_clipspace.xy, positions.y, project_uViewportSize, instancePositions, instanceWidths);'
  );
}

export default class ArcBrushingLayer extends ArcLayer {
  getShaders() {
    const shaders = super.getShaders();
    return {
      vs: this.is64bitEnabled()
        ? addBrushingVs64Shader(shaders.vs)
        : addBrushingVsShader(shaders.vs),
      fs: shaders.fs,
      modules: shaders.modules.concat(['brushing'])
    };
  }

  draw(opts) {
    const {uniforms} = opts;

    const {
      brushSource,
      brushTarget,
      brushRadius,
      enableBrushing,
      mousePosition,
      strokeScale
    } = this.props;

    super.draw({
      ...opts,
      uniforms: {
        ...uniforms,
        brushing_uBrushSource: brushSource ? 1 : 0,
        brushing_uBrushTarget: brushTarget ? 1 : 0,
        brushing_uBrushRadius: brushRadius,
        brushing_uEnableBrushing: enableBrushing ? 1 : 0,
        brushing_uStrokeScale: strokeScale,
        brushing_uMousePosition: mousePosition
          ? new Float32Array(this.unproject(mousePosition))
          : defaultProps.mousePosition
      }
    });
  }
}

ArcBrushingLayer.layerName = 'ArcBrushingLayer';
ArcBrushingLayer.defaultProps = defaultProps;