Method compose

Misc/Palette.cpp:78–127

}

void
Palette::compose(void)
{
  unsigned char bit, byte;
  qreal alpha, r0, r1, g0, g1, b0, b1;

  int prev = -1;
  int i, j;

  for (i = 0; i < SIGDIGGER_PALETTE_MAX_STOPS; ++i) {
    byte = static_cast<unsigned char>(i >> 3);
    bit  = i & 7;

    if (this->bitmap[byte] & (1 << bit)) {
      /* Used color found! */
      if (prev == -1) {
        /* This is the first stop. Fill from 0 until this one */
        for (j = 0; j < i; ++j)
          this->gradient[j] = this->gradient[i];
      } else {
        /* Not the first stop. perform square root mixing */
        for (j = prev + 1; j < i; ++j) {
          alpha = static_cast<qreal>(j - prev) / static_cast<qreal>(i - prev);

          r0 = this->gradient[i].redF();
          r1 = this->gradient[prev].redF();

          g0 = this->gradient[i].greenF();
          g1 = this->gradient[prev].greenF();

          b0 = this->gradient[i].blueF();
          b1 = this->gradient[prev].blueF();

          this->gradient[j].setRgbF(
                sqrt(alpha * r0 * r0 + (1. - alpha) * r1 * r1),
                sqrt(alpha * g0 * g0 + (1. - alpha) * g1 * g1),
                sqrt(alpha * b0 * b0 + (1. - alpha) * b1 * b1));
        }
      }

      prev = i;
    }
  }

  if (prev != -1)
    for (j = prev + 1; j < SIGDIGGER_PALETTE_MAX_STOPS; ++j)
      this->gradient[j] = this->gradient[prev];

  this->updateThumbnail();
}

void
Palette::addStop(unsigned int stop, const QColor &color)