public void Crawl(Point startingPoint, Color targetColor, Color newColor)
{
if (ColorComparer.AreAlike(targetColor, newColor))
throw new ArgumentException(nameof(targetColor) + " can't be alike " + nameof(newColor));
Scanlines.Clear();
// Initialize the starting point
if (IsValid(startingPoint.X, startingPoint.Y, targetColor))
MarkAsInvalid(startingPoint.X, startingPoint.Y, newColor);
else
return;
// Adds the first scanlineData to the stack
var firstLine = new ScanlineData(left: startingPoint.X,
right: startingPoint.X,
y: startingPoint.Y,
directionTheCrawlerIsGoing: ScanlineData.Direction.None,
shouldBeExtendedLeft: true,
shouldBeExtendedRight: true);
Scanlines.Push(firstLine);
while (Scanlines.Count > 0)
{
var currentLine = Scanlines.Pop();
if (currentLine.ShouldBeExtendedLeft)
currentLine = CrawLeft(currentLine, targetColor, newColor);
if (currentLine.ShouldBeExtendedRight)
currentLine = CrawRight(currentLine, targetColor, newColor);
// Bitmap's minimum y value is known to be 0
if (currentLine.Y >= 0)
CheckAbove(currentLine, targetColor, newColor);
//if (CurrentY < MaximumY - 1)
// CheckBelow();
}
}
private void CheckAbove(ScanlineData currentData, Color targetColor, Color newColor)
{
throw new NotImplementedException();
/*
int localHeight = CurrentY - 1;
var nextData = new ScanlineData(ExtendedLeft, ExtendedLeft, localHeight, ScanlineData.Direction.Up, false, false);
bool canSkipMiddleOfTheLine = CurrentLine.DirectionTheCrawlerIsGoing == ScanlineData.Direction.Down;
bool dataIsValid = false;
bool pushedFirstLine = false;
// Checking for trivial cases
if (canSkipMiddleOfTheLine && ExtendedLeft == ExtendedRight)
return;
int x = ExtendedLeft;
int y = localHeight;
for (int movingX = ExtendedLeft; movingX <= ExtendedRight; movingX++)
{
x = movingX;
if (IsValid(x, y))
{
MarkAsInvalid(x, y);
if (!dataIsValid)
{
dataIsValid = true;
nextData.Left = movingX;
}
nextData.Right = movingX;
}
else
{
if (dataIsValid)
{
if (!pushedFirstLine)
{
nextData.ShouldBeExtendedLeft = nextData.Left == ExtendedLeft;
ranges.Push(nextData);
pushedFirstLine = true;
}
else
{
ranges.Push(nextData);
}
dataIsValid = false;
nextData = new ScanlineData(movingX, movingX, localHeight, ScanlineData.Direction.Up, false, false);
}
}
if (movingX == CurrentLine.Left && canSkipMiddleOfTheLine)
{
// Skip previously-checked points
if (dataIsValid)
{
ranges.Push(nextData);
//nextData = new ScanlineData(movingX, movingX, localHeight, ScanlineData.Direction.Up, false, false);
nextData = new ScanlineData(CurrentLine.Right, CurrentLine.Right, localHeight, ScanlineData.Direction.Up, false, false);
}
dataIsValid = false;
movingX = CurrentLine.Right;
}
}
if (dataIsValid && nextData.Right == ExtendedRight)
{
nextData.ShouldBeExtendedLeft = (nextData.Left == ExtendedLeft);
nextData.ShouldBeExtendedRight = true;
ranges.Push(nextData);
}
*/
}
private ScanlineData CrawRight(ScanlineData currentData, Color targetColor, Color newColor)
{
int x = currentData.Right;
int maximumX = Bitmap.Width - 1;
// The idea is to find the biggest x value for the current y
// that still makes IsValid(...) return true
while (x <= maximumX)
{
x++;
if (IsValid(x, currentData.Y, targetColor))
{
MarkAsInvalid(x, currentData.Y, newColor);
}
else
{
// This means increased x one too many times, oughta undo it and stop trying
x--;
break;
}
}
var newScanline = new ScanlineData(left: currentData.Left,
right: x,
y: currentData.Y,
directionTheCrawlerIsGoing: currentData.DirectionTheCrawlerIsGoing,
shouldBeExtendedLeft: currentData.ShouldBeExtendedLeft,
shouldBeExtendedRight: false);
return newScanline;
}
private ScanlineData CrawLeft(ScanlineData currentData, Color targetColor, Color newColor)
{
int x = currentData.Left;
// Bitmap's minimum x value is known to be 0
int minimumX = 0;
// The idea is to find the smallest x value for the current y
// that still makes IsValid(...) return true
while (x >= minimumX)
{
x--;
if (IsValid(x, currentData.Y, targetColor))
{
MarkAsInvalid(x, currentData.Y, newColor);
}
else
{
// This means decreased x one too many times, oughta undo it and stop trying
x++;
break;
}
}
var newScanline = new ScanlineData(left: x,
right: currentData.Right,
y: currentData.Y,
directionTheCrawlerIsGoing: currentData.DirectionTheCrawlerIsGoing,
shouldBeExtendedLeft: false,
shouldBeExtendedRight: currentData.ShouldBeExtendedRight);
return newScanline;
}
/// <summary>
/// Checks the points directly below the current line. MarkAsInvalid the valid ones and, if necessary, creates new ScanLineDatas to be extended.checked.
/// </summary>
protected void CheckBelow()
{
int localHeight = CurrentY + 1;
var nextData = new ScanlineData(ExtendedLeft, ExtendedLeft, localHeight, ScanlineData.Direction.Down, false, false);
bool canSkipMiddleOfTheLine = CurrentLine.DirectionTheCrawlerIsGoing == ScanlineData.Direction.Up;
bool dataIsValid = false;
bool pushedFirstLine = false;
// Checking for trivial cases
if (canSkipMiddleOfTheLine && ExtendedLeft == ExtendedRight) return;
int x = ExtendedLeft;
int y = localHeight;
for (int movingX = ExtendedLeft; movingX <= ExtendedRight; movingX++)
{
x = movingX;
if (IsValid(x, y))
{
MarkAsInvalid(x, y);
if (!dataIsValid)
{
dataIsValid = true;
nextData.Left = movingX;
}
nextData.Right = movingX;
}
else
{
if (dataIsValid)
{
if (!pushedFirstLine)
{
nextData.ShouldBeExtendedLeft = nextData.Left == ExtendedLeft;
ranges.Push(nextData);
pushedFirstLine = true;
}
else
{
ranges.Push(nextData);
}
dataIsValid = false;
nextData = new ScanlineData(movingX, movingX, localHeight, ScanlineData.Direction.Down, false, false);
}
}
if (movingX == CurrentLine.Left && canSkipMiddleOfTheLine)
{
// Skip previously-checked points
if (dataIsValid)
{
ranges.Push(nextData);
nextData = new ScanlineData(movingX, movingX, localHeight, ScanlineData.Direction.Down, false, false);
}
dataIsValid = false;
movingX = CurrentLine.Right;
}
}
if (dataIsValid && nextData.Right == ExtendedRight)
{
nextData.ShouldBeExtendedLeft = (nextData.Left == ExtendedLeft);
nextData.ShouldBeExtendedRight = true;
ranges.Push(nextData);
}
}
/// <summary>
/// Starts crawling. The crawler will check all points that are connected to this one and mark them as already visited as it goes.
/// Stops when there are no more points connected to the initial one.
/// </summary>
/// <param name="startingX">Ininitial x coordinate.</param>
/// <param name="startingY">Ininitial y coordinate.</param>
/// <param name="minimumX">Minimum including value of x.</param>
/// <param name="minimumY">Minimum including value of Y.</param>
/// <param name="maximumX">Maximum non-including value of x.</param>
/// <param name="maximumY">Maximum non-including value of y.</param>
protected void Crawl(int startingX, int startingY, int minimumX, int minimumY, int maximumX, int maximumY)
{
MinimumY = minimumY;
MaximumY = maximumY;
MinimumX = minimumX;
MaximumX = maximumX;
PreCrawlMethods();
if (IsValid(startingX, startingY))
MarkAsInvalid(startingX, startingY);
else
return;
// "Crawls" the startingPoint
ranges.Push(new ScanlineData(startingX, startingX, startingY, ScanlineData.Direction.None, true, true));
while (ranges.Count > 0)
{
CurrentLine = ranges.Pop();
ExtendedLeft = CurrentLine.Left;
ExtendedRight = CurrentLine.Right;
CurrentY = CurrentLine.Y;
if (CurrentLine.ShouldBeExtendedLeft)
ExtendLeft();
if (CurrentLine.ShouldBeExtendedRight)
ExtendRight();
/*(if (currentY > ValidArea.Y)
CheckAbove();
*/
if (CurrentY > MinimumY)
CheckAbove();
/*if (currentY < ValidArea.Bottom - 1)
CheckBelow();
*/
if (CurrentY < MaximumY - 1)
CheckBelow();
}
PostCrawlMethods();
}
