private void InsertAfterSelf(ConstraintSegment segment)
{
segment.Prev = this;
// Order is important
segment.Next = Next;
if (Next != null)
{
Next.Prev = segment;
}
Next = segment;
}
public ConstraintSegment CreateNext(Constraint constraint)
{
Debug.Assert(Next == null);
if (constraint.color == this.Constraint.color)
{
// We need to create a constraint side-by-side with the same color -> introduce a gap
Constraint newConstraint = new Constraint {
color = ColorSpace.Empty, number = 1
};
ConstraintSegment gapSegment = CreateNext(newConstraint);
Debug.Assert(gapSegment.IsGap);
return(gapSegment.CreateNext(constraint));
}
var newSegment = new ConstraintSegment(constraint, EndIndex);
InsertAfterSelf(newSegment);
return(newSegment);
}
public ConstrainResult ConstrainBoard(IBoardView boardView)
{
ConstraintSegment.CreateChain(constraintSet, out ConstraintSegment segmentBegin, out ConstraintSegment segmentEnd);
// Start final colors as completely empty: no colors possible at all
ColorSet[] finalColors = new ColorSet[boardView.Count];
do
{
IReadOnlyList <uint> segmentColors = GetColorsFromSegments(segmentBegin);
if (AreCompatible(boardView, segmentColors))
{
Merge(segmentColors, finalColors);
}
} while (segmentEnd.Bump(boardView.Count));
// TODO: this will place this constraint on the dirty list again, which is slightly redundant...
var result = boardView.IntersectAll(finalColors);
return(result);
}
private void GrowForBump()
{
// Our Next has just moved up by 1
if (IsGap)
{
// Just grow the gap
var con = Constraint; // This copies
con.number++;
Constraint = con;
Debug.Assert(EndIndex == Next.StartIndex);
return;
}
// We need to introduce a new gap object gap
var constraint = new Constraint {
color = ColorSpace.Empty, number = 1
};
ConstraintSegment gap = new ConstraintSegment(constraint, EndIndex);
InsertAfterSelf(gap);
}
public static void CreateChain(IEnumerable <Constraint> constraints, out ConstraintSegment begin, out ConstraintSegment end)
{
begin = null;
end = null;
ConstraintSegment current = null;
foreach (Constraint constr in constraints)
{
if (current == null)
{
current = new ConstraintSegment(constr, 0);
begin = current;
}
else
{
current = current.CreateNext(constr);
}
}
end = current;
}
private IReadOnlyList <uint> GetColorsFromSegments(ConstraintSegment begin)
{
uint[] colorSets = new uint[boardSize];
ConstraintSegment current = begin;
uint emptyColor = ColorSpace.Empty; //ColorSet emptyColor = ColorSet.Empty.AddColor(ColorSpace.Empty);
int i = 0;
while (i != current.StartIndex)
{
colorSets[i] = emptyColor;
i++;
}
while (current != null)
{
Debug.Assert(i == current.StartIndex);
uint currentColor = current.Constraint.color;
while (i != current.EndIndex)
{
colorSets[i] = currentColor;
i++;
}
current = current.Next;
}
while (i != boardSize)
{
colorSets[i] = emptyColor;
i++;
}
return(colorSets);
}
