message: Add some assertions
diff: @@ -288,6 +288,11 @@ int discrSeg(const Point2D &a,
  std::vector<OctType> &out,
  int idx)
  {
  + // Assert input assumptions
  + SLIC_ASSERT(b[0] - a[0] >= 0);
  + SLIC_ASSERT(a[1] >= 0);
  + SLIC_ASSERT(b[1] >= 0);
  +
  // Deal with degenerate segments
  if (b[0] - a[0] < PTINY) { return 0; }
  if (a[1] < PTINY && b[1] < PTINY) { return 0; }
  