public PixelCollection FloodFill(PixelCollection pixels, Pixel fillPixel, Color targetColor, Color replacementColor)
{
if (targetColor.Equals(replacementColor))
{
return(pixels);
}
if (!fillPixel.Color.Equals(targetColor))
{
return(pixels);
}
var pixelQueue = new Queue <Pixel>();
pixels.SetPixel(fillPixel, replacementColor);
pixelQueue.Enqueue(fillPixel);
Pixel currentPixel;
while (pixelQueue.Count > 0)
{
currentPixel = pixelQueue.Dequeue();
var northPixel = pixels.GetPixelOrNull(currentPixel.Column, currentPixel.Row - 1);
var southPixel = pixels.GetPixelOrNull(currentPixel.Column, currentPixel.Row + 1);
var eastPixel = pixels.GetPixelOrNull(currentPixel.Column + 1, currentPixel.Row);
var westPixel = pixels.GetPixelOrNull(currentPixel.Column - 1, currentPixel.Row);
TryToColorPixel(pixels, pixelQueue, northPixel, targetColor, replacementColor);
TryToColorPixel(pixels, pixelQueue, southPixel, targetColor, replacementColor);
TryToColorPixel(pixels, pixelQueue, eastPixel, targetColor, replacementColor);
TryToColorPixel(pixels, pixelQueue, westPixel, targetColor, replacementColor);
}
return(pixels);
}