// VectorSSI - SSI with straight line segments

persistable sclass VectorSSI extends AbstractSSI {
  replace X with short.
  replace Y with short.
  replace toX with toShort_enforce.
  replace toY with toShort_enforce.
  replace newXArray with newShortArrayOrNull.
  
  // core values (mandatory): first column and row occupied
  settable X x1;
  settable Y y1;
  
  // Curves of x start and x end, relative to (x1, y1)
  // Both have same length
  settable InterpolatedDoubleArray leftCurve;
  settable InterpolatedDoubleArray rightCurve;
  
  *(SSI ssi) {
    Rect r = ssi.bounds();
    x1(toX(r.x1()));
    y1(toY(r.y1()));
    int h = r.h();
    int[] left = new int[h], right = new int[h];
    for y to h: {
      left[y] = ssi.getLeft(y1+y)-x1;
      right[y] = ssi.getRight(y1+y)-x1;
    }
    leftCurve(CompressToInterpolatedDoubleArray(left)!);
    rightCurve(CompressToInterpolatedDoubleArray(right)!);
  }
  
  int height aka h() {
    ret leftCurve.length();
  }
  
  int y2() {
    ret y1+h();
  }
  
  SSI toSSI aka get() {
    int h = h();
    var ssi = new SSI(y1, y2());
    int[] left = leftCurve.rounded();
    int[] right = rightCurve.rounded();
    for y to h:
      ssi.set(y1+y, x1+left[y], x1+right[y]);
    ret ssi;
  }
}