Convert from hue saturation value / lightness (alpha) to red green blue (alpha)

HSV to RGB (HSVA TO RGBA).cpp

  static RGBA HSVAToRGBA(float h, float s, float v, float a) {
    float hh = std::fmodf(h, 360.0f) / 60.0f;

    uint32_t i = static_cast<uint32_t>(hh);

    float ff = hh - float(i);

    float p = v * (1.0f - s);
    float q = v * (1.0f - (s * ff));
    float t = v * (1.0f - (s * (1.0f - ff)));

    switch (i) {
      case 0: return { v, t, p, a };
      case 1: return { q, v, p, a };
      case 2: return { p, v, t, a };
      case 3: return { p, q, v, a };
      case 4: return { t, p, v, a };
      default:
      case 5: return { v, p, q, a };
    }
  }