//---------------------------------------------------------------------
public bool MoveNext()
{
if (atEnd)
return false;
if (moveNextNotCalled) {
InitializeCurrentSite();
moveNextNotCalled = false;
return true;
}
Location nextLocation = RowMajor.Next(currentSite.Location, landscape.Columns);
if (nextLocation.Row > landscape.Rows) {
atEnd = true;
return false;
}
if (currentSite.IsActive) {
// current site is the active site etor's Current property
// so advance etor to next active site.
if (activeSiteEtor.MoveNext()) {
// There is one or more active sites remaining.
nextActiveSite = activeSiteEtor.Current;
if (nextLocation == nextActiveSite.Location) {
// Leave current site pointing to active site etor
}
else {
// Next site is inactive.
currentSite = inactiveSite;
inactiveSite.SetLocation(nextLocation);
}
}
else {
// No more active sites left to visit, so next site is
// inactive.
nextActiveSite = null;
currentSite = inactiveSite;
inactiveSite.SetLocation(nextLocation);
}
}
else {
// Current site is inactive
if (nextActiveSite != null && nextLocation == nextActiveSite.Location)
currentSite = nextActiveSite;
else {
// Leave current site pointing to the local inactive site
// instance, and just change its location.
inactiveSite.SetLocation(nextLocation);
}
}
return true;
}
//---------------------------------------------------------------------
public T ReadValue()
{
if (disposed)
{
throw new System.InvalidOperationException("Object has been disposed.");
}
currentLocation = RowMajor.Next(currentLocation, Columns);
if (currentLocation.Row > Rows)
{
throw new System.IO.EndOfStreamException();
}
return(data[currentLocation]);
}
//---------------------------------------------------------------------
/// <summary>
/// Gets the next active site in row-major order.
/// </summary>
/// <param name="site">
/// Current site's location and data index.
/// </param>
/// <returns>
/// true if the next active site's location and data index have been
/// assigned to the site parameter. false if there are no more active
/// sites.
/// </returns>
public bool GetNextActive(ref LocationAndIndex site)
{
Location nextLoc = RowMajor.Next(site.Location, columns);
while (nextLoc.Row <= rows)
{
uint index = indexes[nextLoc.Row - 1, nextLoc.Column - 1];
if (index != InactiveSiteDataIndex)
{
site.Location = nextLoc;
site.Index = index;
return(true);
}
nextLoc = RowMajor.Next(nextLoc, columns);
}
return(false);
}
