public static void FloodFill(Bitmap bmp, SimplePoint pt, Color replacementColor)
{
if (pt.X == 0 || pt.Y == 0 || pt.X >= bmp.Width || pt.Y >= bmp.Height)
{
return;
}
var targetColor = bmp.GetPixel(pt.X, pt.Y);
if (targetColor == replacementColor)
{
return;
}
var pixels = new Stack <SimplePoint>();
pixels.Push(pt);
while (pixels.Count != 0)
{
var temp = pixels.Pop();
int y1 = temp.Y;
while (y1 >= 0 && bmp.GetPixel(temp.X, y1) == targetColor)
{
y1--;
}
y1++;
var spanLeft = false;
var spanRight = false;
while (y1 < bmp.Height && bmp.GetPixel(temp.X, y1) == targetColor)
{
bmp.SetPixel(temp.X, y1, replacementColor);
if (!spanLeft && temp.X > 0 && bmp.GetPixel(temp.X - 1, y1) == targetColor)
{
var np = new SimplePoint(temp.X - 1, y1);
pixels.Push(np);
spanLeft = true;
}
else if (spanLeft && temp.X - 1 == 0 && bmp.GetPixel(temp.X - 1, y1) != targetColor)
{
spanLeft = false;
}
if (!spanRight && temp.X < bmp.Width - 1 && bmp.GetPixel(temp.X + 1, y1) == targetColor)
{
var np = new SimplePoint(temp.X + 1, y1);
pixels.Push(np);
spanRight = true;
}
else if (spanRight && temp.X < bmp.Width - 1 && bmp.GetPixel(temp.X + 1, y1) != targetColor)
{
spanRight = false;
}
y1++;
}
}
}
public static SimplePoint[] GetPoints(Bitmap bmp, SimplePoint pt)
{
if (pt.X == 0 || pt.Y == 0 || pt.X >= bmp.Width || pt.Y >= bmp.Height)
{
return(null);
}
var targetColor = bmp.GetPixel(pt.X, pt.Y);
if (Math.Abs(targetColor.R) < 0.001 &&
Math.Abs(targetColor.G) < 0.001 &&
Math.Abs(targetColor.B) < 0.001)
{
return(null);
}
var l = new List <SimplePoint>();
var pixels = new Stack <SimplePoint>();
pixels.Push(pt);
while (pixels.Count != 0)
{
var temp = pixels.Pop();
int y1 = temp.Y;
while (y1 >= 0 && bmp.GetPixel(temp.X, y1) == targetColor)
{
y1--;
}
y1++;
var spanLeft = false;
var spanRight = false;
while (y1 < bmp.Height && bmp.GetPixel(temp.X, y1) == targetColor)
{
l.Add(new SimplePoint(temp.X, y1));
if (!spanLeft && temp.X > 0 && bmp.GetPixel(temp.X - 1, y1) == targetColor)
{
var np = new SimplePoint(temp.X - 1, y1);
if (!l.Any(x => x.X == np.X && x.Y == np.Y))
{
pixels.Push(np);
spanLeft = true;
}
}
else if (spanLeft && temp.X - 1 == 0 && bmp.GetPixel(temp.X - 1, y1) != targetColor)
{
spanLeft = false;
}
if (!spanRight && temp.X < bmp.Width - 1 && bmp.GetPixel(temp.X + 1, y1) == targetColor)
{
var np = new SimplePoint(temp.X + 1, y1);
if (!l.Any(x => x.X == np.X && x.Y == np.Y))
{
pixels.Push(np);
spanRight = true;
}
}
else if (spanRight && temp.X < bmp.Width - 1 && bmp.GetPixel(temp.X + 1, y1) != targetColor)
{
spanRight = false;
}
y1++;
}
}
return(l.ToArray());
}
