// Detect blocks of formula copies, for finding compact support sets
public void AddToSupportSets()
{
int sheetCols = Cols, sheetRows = Rows;
cells.Forall((int col, int row, Cell cell) => {
if (cell is ArrayFormula)
{
// Do not try to detect copies of array formulas.
// CHECK THIS!
ArrayFormula af = cell as ArrayFormula;
af.AddToSupportSets(this, col, row, 1, 1);
}
else if (cell is Formula)
{
Formula f = cell as Formula;
if (!f.Visited)
{
Expr expr = f.Expr;
// (1) Find a large rectangle containing only formula f
// (1a) Find largest square of copies with upper left corner = (col, row)
int size = 1;
while (col + size < sheetCols && row + size < sheetRows &&
CheckCol(col + size, row, expr, size) &&
CheckRow(col, row + size, expr, size))
{
size++;
}
// All cells in sheet[col..col+size-1, row..row+size-1] contain expression expr
// (1b) Try extending square with more rows below
int rowSize = size;
while (row + rowSize < sheetRows && CheckRow(col, row + rowSize, expr, size - 1))
{
rowSize++;
}
// sheet[col..col+size-1, row..row+rows-1] contains expr
// (1c) Try extending square with more columns to the right
int cols = size;
while (col + cols < sheetCols && CheckCol(col + cols, row, expr, size - 1))
{
cols++;
}
// sheet[col..col+cols-1, row..row+size-1] contains expr
if (rowSize > cols)
{
cols = size;
}
else
{
rowSize = size;
}
// All cells in sheet[col..col+cols-1, row..row+rows-1] contain expression expr
// (2) Mark all cells in the rectangle visited
for (int deltaCol = 0; deltaCol < cols; deltaCol++)
{
for (int deltaRow = 0; deltaRow < rowSize; deltaRow++)
{
(this[col + deltaCol, row + deltaRow] as Formula).Visited = true;
}
}
// (3) Update the support sets of cells referred to from expr
expr.AddToSupportSets(this, col, row, cols, rowSize);
}
}
});
this.ResetCellState(); // Undo changes made to the sheet's cells' states
}
public override void AddToSupportSets(Sheet supported, int col, int row, int cols, int rows)
{
e.AddToSupportSets(supported, col, row, cols, rows);
}