view src/app/spectrogram/ColourMap.ts @ 394:f45a916eb5b1

Use the cross hair layer for notes, tracks and curve. This involved bodging in unit to ShapedFeatureData, which isn't particularly easy to do because this isn't an encapsulated type. Need to come back to improving this, as I am monkey-patching a unit property onto Arrays etc.

/**
 * Created by lucast on 23/05/2017.
 */

export function interpolatingMapper(hexColours) {
  const colours = hexColours.map(n => {
    const i = parseInt(n, 16);
    return [ ((i >> 16) & 255) / 255.0,
      ((i >> 8) & 255) / 255.0,
      ((i) & 255) / 255.0 ];
  });
  const last = colours.length - 1;
  return (value => {
    const m = value * last;
    if (m >= last) {
      return colours[last];
    }
    if (m <= 0) {
      return colours[0];
    }
    const base = Math.floor(m);
    const prop0 = base + 1.0 - m;
    const prop1 = m - base;
    const c0 = colours[base];
    const c1 = colours[base + 1];
    return [ c0[0] * prop0 + c1[0] * prop1,
      c0[1] * prop0 + c1[1] * prop1,
      c0[2] * prop0 + c1[2] * prop1 ];
  });
}

export function iceMapper() {
  const hexColours = [
    // Based on ColorBrewer ylGnBu
    'ffffff', 'ffff00', 'f7fcf0', 'e0f3db', 'ccebc5', 'a8ddb5',
    '7bccc4', '4eb3d3', '2b8cbe', '0868ac', '084081', '042040'
  ];
  hexColours.reverse();
  return interpolatingMapper(hexColours);
}

export function greenMapper() {
  const blue = 0.6666;
  const pieslice = 0.3333;
  return (value => {
    const h = blue - value * 2.0 * pieslice;
    const s = 0.5 + value / 2.0;
    const v = value;
    return this.hsv2rgb(h, s, v);
  });
}

export function sunsetMapper() {
  return (value => {
    const r = (value - 0.24) * 2.38;
    const g = (value - 0.64) * 2.777;
    let b = (3.6 * value);
    if (value > 0.277) {
      b = 2.0 - b;
    }
    return [ r, g, b ];
  });
}

export function hsv2rgb(h, s, v) { // all values in range [0, 1]
  const i = Math.floor(h * 6);
  const f = h * 6 - i;
  const p = v * (1 - s);
  const q = v * (1 - f * s);
  const t = v * (1 - (1 - f) * s);
  let r = 0, g = 0, b = 0;
  switch (i % 6) {
    case 0: r = v; g = t; b = p; break;
    case 1: r = q; g = v; b = p; break;
    case 2: r = p; g = v; b = t; break;
    case 3: r = p; g = q; b = v; break;
    case 4: r = t; g = p; b = v; break;
    case 5: r = v; g = p; b = q; break;
  }
  return [ r, g, b ];
}