// 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) {

    ssi.copyAbstractSSI(this);

    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)!);

  }

  public 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());

    copyAbstractSSI(ssi);

    int[] left = leftCurve.rounded();

    int[] right = rightCurve.rounded();

    for y to h:

      ssi.set(y1+y, x1+left[y], x1+right[y]);

    ret ssi;

  }

  public void drawOn(Graphics2D g) {

    toSSI().drawOn(g);

  }

  // How many points define the shape of this vector SSI

  // (left + right border)

  int nPoints() {

    ret leftCurve.nPillars() + rightCurve.nPillars();

  }

  public long sizeInInts() {

    // "v", color, x1, y1, height(), leftCurve, rightCurve

    ret 5+leftCurve.nInts/*_withoutFirstAndLastIndex*/()+rightCurve.nInts/*_withoutFirstAndLastIndex*/();

  }

  // TODO

  /*VectorSSI reduceToInts(int ints) {

    ints -= 5; // constant part

    int nPillars = ints/2; // max pillars we can afford (left+right)

  }*/

  // optimizable

  public simplyCached Rect bounds() {

    ret toSSI().bounds();

  }

  public simplyCached int numberOfPixels() {

    ret toSSI().numberOfPixels();

  }

  public void readWrite(StringHead head) {

    head.exchangeLine(l0 toLine, l1 fromLine);

  }

  S toLine() {

    L elements = ll("v", colorToString(), x1, y1, height());

    addAll(elements, asList(iroundAll(leftCurve.indicesAndValues/*_withoutFirstAndLastIndex*/())));

    addAll(elements, asList(iroundAll(rightCurve.indicesAndValues/*_withoutFirstAndLastIndex*/())));

    ret spaceCombine(elements);

  }

  void fromLine(S line) {

    Iterator<S> it = splitAtSpaceIterator(line);

    assertEquals("v", nextFromIterator(it));

    x1 = toX(parseInt(nextFromIterator(it)));

    y1 = toY(parseInt(nextFromIterator(it)));

    // TODO

    /*int h = parseInt(nextFromIterator(it));

    init(y1, y1+h);

    for i over data:

      data[i] = toX(parseInt(nextFromIterator(it)));*/

  }

}