///<summary>initializes the FloodFill operation</summary>
public static FloodFillRectangle FloodFill(Bitmap bmp, Point pt, Color color)
{
var c = ToBgra(color);
var rect = new FloodFillRectangle();
//get the bits
var bmpData = bmp.LockBits(new Rectangle(0, 0, bmp.Width, bmp.Height), ImageLockMode.ReadWrite, PixelFormat.Format32bppArgb);
unsafe
{
//resolve pointer
var scan0 = (byte *)(void *)bmpData.Scan0;
//get the starting color
//[loc += Y offset + X offset]
var loc = CoordsToIndex(pt.X, pt.Y, bmpData.Stride); //((bmpData.Stride*(pt.Y-1))+(pt.X*4));
var startColor = *((int *)(scan0 + loc));
//create the array of bools that indicates whether each pixel
//has been checked. (Should be bitfield, but C# doesn't support bitfields.)
var pixelsChecked = new bool[bmpData.Width + 1, bmpData.Height + 1];
LinearFloodFill4(scan0, pt.X, pt.Y, new Size(bmpData.Width, bmpData.Height), bmpData.Stride, (byte *)&startColor, c, pixelsChecked, ref rect);
}
bmp.UnlockBits(bmpData);
return(rect);
}
//***********
//LINEAR ALGORITHM
//***********
private static unsafe void LinearFloodFill4( byte* scan0, int x, int y,Size bmpsize, int stride, byte* startcolor, int color, bool[,] pixelsChecked, ref FloodFillRectangle rect)
{
//offset the pointer to the point passed in
var p=(int*) (scan0+(CoordsToIndex(x,y, stride)));
//FIND LEFT EDGE OF COLOR AREA
var lFillLoc=x; //the location to check/fill on the left
var ptr=p; //the pointer to the current location
while(true)
{
ptr[0]=color; //fill with the color
pixelsChecked[lFillLoc,y]=true;
lFillLoc--; //de-increment counter
ptr-=1; //de-increment pointer
if(lFillLoc<=0 || !CheckPixel((byte*)ptr,startcolor) || (pixelsChecked[lFillLoc,y]))
break; //exit loop if we're at edge of bitmap or color area
}
lFillLoc++;
if (lFillLoc < rect.MinX)
rect.MinX = lFillLoc;
//FIND RIGHT EDGE OF COLOR AREA
var rFillLoc=x; //the location to check/fill on the left
ptr=p;
while(true)
{
ptr[0]=color; //fill with the color
pixelsChecked[rFillLoc,y]=true;
rFillLoc++; //increment counter
ptr+=1; //increment pointer
if(rFillLoc>=bmpsize.Width || !CheckPixel((byte*)ptr,startcolor) || (pixelsChecked[rFillLoc,y]))
break; //exit loop if we're at edge of bitmap or color area
}
rFillLoc--;
if (rFillLoc > rect.MaxX)
rect.MaxX = rFillLoc;
if (y < rect.MinY)
rect.MinY = y;
if (y > rect.MaxY)
rect.MaxY = y;
//START THE LOOP UPWARDS AND DOWNWARDS
ptr=(int*)(scan0+CoordsToIndex(lFillLoc,y,stride));
for(var i=lFillLoc;i<=rFillLoc;i++)
{
//START LOOP UPWARDS
//if we're not above the top of the bitmap and the pixel above this one is within the color tolerance
if(y>0 && CheckPixel(scan0+CoordsToIndex(i,y-1,stride),startcolor) && (!(pixelsChecked[i,y-1])))
LinearFloodFill4(scan0, i,y-1,bmpsize,stride,startcolor, color, pixelsChecked, ref rect);
//START LOOP DOWNWARDS
if(y<(bmpsize.Height-1) && CheckPixel(scan0+CoordsToIndex(i,y+1,stride),startcolor) && (!(pixelsChecked[i,y+1])))
LinearFloodFill4(scan0, i,y+1,bmpsize,stride,startcolor, color, pixelsChecked, ref rect);
ptr+=1;
}
}
///<summary>initializes the FloodFill operation</summary>
public static FloodFillRectangle FloodFill(Bitmap bmp, Point pt, Color color)
{
var c = ToBgra(color);
var rect = new FloodFillRectangle();
//get the bits
var bmpData = bmp.LockBits(new Rectangle(0, 0, bmp.Width, bmp.Height), ImageLockMode.ReadWrite, PixelFormat.Format32bppArgb);
unsafe
{
//resolve pointer
var scan0 = (byte*) (void*)bmpData.Scan0;
//get the starting color
//[loc += Y offset + X offset]
var loc = CoordsToIndex(pt.X, pt.Y, bmpData.Stride); //((bmpData.Stride*(pt.Y-1))+(pt.X*4));
var startColor = *((int*) (scan0 + loc));
//create the array of bools that indicates whether each pixel
//has been checked. (Should be bitfield, but C# doesn't support bitfields.)
var pixelsChecked = new bool[bmpData.Width + 1, bmpData.Height + 1];
LinearFloodFill4(scan0, pt.X, pt.Y, new Size(bmpData.Width, bmpData.Height), bmpData.Stride, (byte*) &startColor, c, pixelsChecked, ref rect);
}
bmp.UnlockBits(bmpData);
return rect;
}
//***********
//LINEAR ALGORITHM
//***********
private static unsafe void LinearFloodFill4(byte *scan0, int x, int y, Size bmpsize, int stride, byte *startcolor, int color, bool[,] pixelsChecked, ref FloodFillRectangle rect)
{
//offset the pointer to the point passed in
var p = (int *)(scan0 + (CoordsToIndex(x, y, stride)));
//FIND LEFT EDGE OF COLOR AREA
var lFillLoc = x; //the location to check/fill on the left
var ptr = p; //the pointer to the current location
while (true)
{
ptr[0] = color; //fill with the color
pixelsChecked[lFillLoc, y] = true;
lFillLoc--; //de-increment counter
ptr -= 1; //de-increment pointer
if (lFillLoc <= 0 || !CheckPixel((byte *)ptr, startcolor) || (pixelsChecked[lFillLoc, y]))
{
break; //exit loop if we're at edge of bitmap or color area
}
}
lFillLoc++;
if (lFillLoc < rect.MinX)
{
rect.MinX = lFillLoc;
}
//FIND RIGHT EDGE OF COLOR AREA
var rFillLoc = x; //the location to check/fill on the left
ptr = p;
while (true)
{
ptr[0] = color; //fill with the color
pixelsChecked[rFillLoc, y] = true;
rFillLoc++; //increment counter
ptr += 1; //increment pointer
if (rFillLoc >= bmpsize.Width || !CheckPixel((byte *)ptr, startcolor) || (pixelsChecked[rFillLoc, y]))
{
break; //exit loop if we're at edge of bitmap or color area
}
}
rFillLoc--;
if (rFillLoc > rect.MaxX)
{
rect.MaxX = rFillLoc;
}
if (y < rect.MinY)
{
rect.MinY = y;
}
if (y > rect.MaxY)
{
rect.MaxY = y;
}
//START THE LOOP UPWARDS AND DOWNWARDS
ptr = (int *)(scan0 + CoordsToIndex(lFillLoc, y, stride));
for (var i = lFillLoc; i <= rFillLoc; i++)
{
//START LOOP UPWARDS
//if we're not above the top of the bitmap and the pixel above this one is within the color tolerance
if (y > 0 && CheckPixel(scan0 + CoordsToIndex(i, y - 1, stride), startcolor) && (!(pixelsChecked[i, y - 1])))
{
LinearFloodFill4(scan0, i, y - 1, bmpsize, stride, startcolor, color, pixelsChecked, ref rect);
}
//START LOOP DOWNWARDS
if (y < (bmpsize.Height - 1) && CheckPixel(scan0 + CoordsToIndex(i, y + 1, stride), startcolor) && (!(pixelsChecked[i, y + 1])))
{
LinearFloodFill4(scan0, i, y + 1, bmpsize, stride, startcolor, color, pixelsChecked, ref rect);
}
ptr += 1;
}
}
