/// <summary>
/// Fills the area surrounding the point with the color passed in
/// </summary>
/// <param name="bitmap">The bitmap to be edited</param>
/// <param name="x">The x value of the pointer location</param>
/// <param name="y">The y value of the pointer location</param>
/// <param name="color">The color to fill the area with</param>
public static void Fill(WriteableBitmap bitmap, int x, int y, int color)
{
toFillWith = color;
//use the using keyword to ensure the BitmapReader is disposed of before the method returns.
using (BitmapReader bmpReader = new BitmapReader(bitmap))
{
toBeFilled = bmpReader.GetPixeli(x, y);
if (toBeFilled != toFillWith)
{
FloodFillScanline(bmpReader, x, y);
}
}
}
public static void RedrawSelection()
{
if (selectionMade && selectionDisplaying)
{
//first do the draw logic for the rectangle
WriteableBitmap oldbmp = new WriteableBitmap(bmp.PixelWidth, bmp.PixelHeight);
oldbmp.PixelBuffer.AsStream().Write(beforeSelection, 0, beforeSelection.Length);
using (BitmapReader oldReader = new BitmapReader(oldbmp))
{
using (BitmapReader newReader = new BitmapReader(bmp))
{
//top line
for (int i = selection.topLeft.x; i <= selection.bottomRight.x; i++)
{
int color = oldReader.GetPixeli(i, selection.topLeft.y);
newReader.SetPixel(i, selection.topLeft.y, color);
}
//bottom line
for (int i = selection.topLeft.x; i <= selection.bottomRight.x; i++)
{
int color = oldReader.GetPixeli(i, selection.bottomRight.y);
newReader.SetPixel(i, selection.bottomRight.y, color);
}
//left line
for (int i = selection.topLeft.y; i <= selection.bottomRight.y; i++)
{
int color = oldReader.GetPixeli(selection.topLeft.x, i);
newReader.SetPixel(selection.topLeft.x, i, color);
}
//right
for (int i = selection.topLeft.y; i <= selection.bottomRight.y; i++)
{
int color = oldReader.GetPixeli(selection.bottomRight.x, i);
newReader.SetPixel(selection.bottomRight.x, i, color);
}
}
}
byte[] b = new byte[beforeSelection.Length];
bmp.PixelBuffer.ToArray().CopyTo(b, 0);
History.EndAction(new Action(b));
bmp.DrawRectangle(selection.topLeft.x, selection.topLeft.y, selection.bottomRight.x, selection.bottomRight.y, Colors.Black);
bmp.Invalidate();
}
}
/// <summary>
/// Uses the scanline algorithm to flood fill a selected area with the color given, starting from the point given.
/// </summary>
/// <param name="x">The X position to start the fill from</param>
/// <param name="y">The Y position to start the fill from</param>
private static void FloodFillScanline(BitmapReader bmpReader, int x, int y)
{
Queue <P> points = new Queue <P>();
points.Enqueue(new P(x, y));
while (points.Count > 0)
{
P temp = points.Dequeue();
int y1 = temp.y;
while (y1 >= 0 && bmpReader.GetPixeli(temp.x, y1) == toBeFilled)
{
y1--;
}
y1++;
bool toBeFilledLeft = false;
bool toBeFilledRight = false;
while (y1 < bmpReader.Height && bmpReader.GetPixeli(temp.x, y1) == toBeFilled)
{
bmpReader.SetPixel(temp.x, y1, toFillWith);
if (!toBeFilledLeft && (temp.x > 0 && bmpReader.GetPixeli(temp.x - 1, y1) == toBeFilled))
{
points.Enqueue(new P(temp.x - 1, y1));
toBeFilledLeft = true;
}
else if (toBeFilledLeft && (temp.x > 0 && bmpReader.GetPixeli(temp.x - 1, y1) != toBeFilled))
{
toBeFilledLeft = false;
}
if (!toBeFilledRight && (temp.x < bmpReader.Width - 1 && bmpReader.GetPixeli(temp.x + 1, y1) == toBeFilled))
{
points.Enqueue(new P(temp.x + 1, y1));
toBeFilledRight = true;
}
else if (toBeFilledRight && (temp.x < bmpReader.Width - 1 && bmpReader.GetPixeli(temp.x + 1, y1) != toBeFilled))
{
toBeFilledRight = false;
}
y1++;
}
}
}
