bool RegionOfRows::GetIntersection(const RegionOfRows& RegionOI,RegionOfRows& Intersection) const
{
Intersection.Reset();
// Regions are defined ?
if (!IsDefined()) return false;
if (!RegionOI.IsDefined()) return false;
// Regions are defined, do the have common rows ?
const ClosedInterval<unsigned int>* Region1Rows = GetRows();
const ClosedInterval<unsigned int>* Region2Rows = RegionOI.GetRows();
ClosedInterval<unsigned int> RowsOI;
if (!Region1Rows->GetOverlap(*Region2Rows,RowsOI)) return false; // no rows in common
unsigned int RowStart = RowsOI.GetStart();
unsigned int RowEnd = RowsOI.GetEnd();
const ClosedInterval<unsigned int>* Columns1 = GetColumns();
const ClosedInterval<unsigned int>* Columns2 = RegionOI.GetColumns();
// Adjust offets
Columns1 += RowStart - GetFirstRow();
Columns2 += RowStart - RegionOI.GetFirstRow();
for (unsigned int Row = RowStart;Row <= RowEnd;Row++)
{
ClosedInterval<unsigned int> ColumnsOI;
if (Columns1->GetOverlap(*Columns2,ColumnsOI))
{
// Rows and columns in common => intersection
Intersection.Add(Row,ColumnsOI.GetStart(),ColumnsOI.GetEnd());
} else if (Intersection.IsDefined()) break; // Convex region !
Columns1++;
Columns2++;
}
// Any intersection ?
return Intersection.IsDefined();
}
void RegionOfRows::ShiftRegion(int RowDisplacement,int ColumnDisplacement)
{
if (!IsDefined()) return;
if (RowDisplacement != 0)
{
// Shift rows
int StartRow = (int) Rows.GetStart();
StartRow += RowDisplacement;
if (StartRow < 0)
{
// Can't shift => invalidate !
Reset();
return;
}
int EndRow = (int) Rows.GetEnd();
EndRow += RowDisplacement;
Rows.Set((unsigned int)StartRow,(unsigned int)EndRow);
}
if (ColumnDisplacement != 0)
{
// Shift Columns
ClosedInterval<unsigned int>* MyColumns = GetMyColumns();
unsigned int NumberOfRows = Rows.GetSpan() + 1;
for (unsigned int i=0; i < NumberOfRows;++i)
{
int StartColumn = (int) MyColumns->GetStart();
StartColumn += ColumnDisplacement;
if (StartColumn < 0)
{
// Can't shift => invalidate !
Reset();
return;
}
int EndColumn = (int) MyColumns->GetEnd();
EndColumn += ColumnDisplacement;
MyColumns->Set((unsigned int)StartColumn,(unsigned int)EndColumn);
MyColumns++;
}
}
}