static void _assigndir(double* x, double* y, const double* b)
{
  x[1]=b[0];
  y[1]=b[1];
  x[2]=b[2];
  y[2]=b[3];
}

static void _applydir(double* x, double* y, double w0, double w1, const double* b0, const double* b1)
{
  x[1]=w0*b0[0]+w1*b1[0];
  y[1]=w0*b0[1]+w1*b1[1];
  x[2]=w0*b0[2]+w1*b1[2];
  y[2]=w0*b0[3]+w1*b1[3];
}

bool GetMediaItemFadeBezParms(int shape, double dir, bool isfadeout,
  double* x, double* y) // x[4], y[4] .. returns true if the fade is linear
{
  static const double b0[4] = { 0.5, 0.5, 0.5, 0.5 };
  static const double b1[4] = { 0.25, 0.5, 0.625, 1.0 };
  static const double b2[4] = { 0.375, 0.0, 0.75, 0.5 };
  static const double b3[4] = { 0.25, 1.0, 0.5, 1.0 };
  static const double b4[4] = { 0.5, 0.0, 0.75, 0.0 };
  static const double b5[4] = { 0.375, 0.0, 0.625, 1.0 };
  static const double b6[4] = { 0.875, 0.0, 0.125, 1.0 };
  static const double b7[4] = { 0.25, 0.375, 0.625, 1.0 };

  static const double b4i[4] = { 0.0, 1.0, 0.125, 1.0 };
  static const double b50[4] = { 0.25, 0.25, 0.25, 1.0 };
  static const double b51[4] = { 0.75, 0.0, 0.75, 0.75 };
  static const double b60[4] = { 0.375, 0.25, 0.0, 1.0 };
  static const double b61[4] = { 1.0, 0.0, 0.625, 0.75 };

  if (!isfadeout)
  {
    x[0]=y[0]=0.0;
    x[3]=y[3]=1.0;
  }
  else
  {
    x[0]=y[3]=0.0;
    x[3]=y[0]=1.0;
  }


  if (shape < 0 || shape >= NUM_FADE_SHAPES)
  {
    shape=0;
    dir=0.0;
  }

  if (isfadeout) dir=-dir;

  bool linear=false;

  if (dir < 0.0)
  {
    double w0=-dir;
    double w1=1.0+dir;
    if (shape == 1) _applydir(x, y, w0, w1, b4i, b1);
    else if (shape == 2) _applydir(x, y, w0, w1, b1, b0);
    else if (shape == 5) _applydir(x, y, w0, w1, b50, b5);
    else if (shape == 6) _applydir(x, y, w0, w1, b60, b6);
    else if (shape == 7) _applydir(x, y, w0, w1, b4i, b7);
    else _applydir(x, y, w0, w1, b3, b0);
  }
  else if (dir > 0.0)
  {
    double w0=1.0-dir;
    double w1=dir;
    if (shape == 1) _applydir(x, y, w0, w1, b1, b4);
    else if (shape == 2) _applydir(x, y, w0, w1, b0, b2);
    else if (shape == 5) _applydir(x, y, w0, w1, b5, b51);
    else if (shape == 6) _applydir(x, y, w0, w1, b6, b61);
    else if (shape == 7) _applydir(x, y, w0, w1, b7, b4);
    else _applydir(x, y, w0, w1, b0, b4);
  }
  else // dir == 0.0
  {
    if (shape == 1) _assigndir(x, y, b1);
    else if (shape == 5) _assigndir(x, y, b5);
    else if (shape == 6) _assigndir(x, y, b6);
    else if (shape == 7) _assigndir(x, y, b7);
    else
    {
      _assigndir(x, y, b0);
      linear=true;
    }
  }

  if (isfadeout && !linear)
  {
    double ox1=x[1];
    double ox2=x[2];
    x[1]=1.0-ox2;
    x[2]=1.0-ox1;
    SWAP(y[1], y[2], double);
  }

  return linear;
}