Method _random

examples/WebCamServer/ESP32WebCam.cpp:494–512

* Generates pseudo-random numbers. * This function is only quoted for boundary string generation for multipart * content. * @param max Maximum range of random numbers to be generated. * @return A generated random number. */

 * @return A generated random number.
 */
long ESP32WebCam::_random(long max) {
  uint32_t  x = esp_random();
  uint64_t  m = uint64_t(x) * uint64_t(max);
  uint32_t  l = uint32_t(m);
  if (l < max) {
    uint32_t  t = -max;
    if (t >= max) {
      t -= max;
      if (t >= max)
        t %= max;
    }
    while (l < t) {
      x = esp_random();
      m = uint64_t(x) * uint64_t(max);
      l = uint32_t(m);
    }
  }
  return m >> 32;
}