Accord.Imaging.Filters.PointedMeanFloodFill.LinearFloodFill4RGB C# (CSharp) Method

        private unsafe void LinearFloodFill4RGB( int x, int y )
        {
            // get image pointer for current (X, Y)
            byte* p = (byte*) CoordsToPointerRGB( x, y );

            // find left end of line to fill
            int leftLineEdge = x;
            byte* ptr = p;

            while ( true )
            {
                // sum value of the current pixel
                meanR += ptr[RGB.R];
                meanG += ptr[RGB.G];
                meanB += ptr[RGB.B];
                pixelsCount++;
                // mark the pixel as checked
                checkedPixels[y, leftLineEdge] = true;

                leftLineEdge--;
                ptr -= 3;

                // check if we need to stop on the edge of image or color area
                if ( ( leftLineEdge < startX ) || ( checkedPixels[y, leftLineEdge] ) || ( !CheckRGBPixel( ptr ) ) )
                    break;

            }
            leftLineEdge++;

            // find right end of line to fill
            int rightLineEdge = x + 1;
            ptr = p + 3;

            // while we don't need to stop on the edge of image or color area
            while ( !( rightLineEdge > stopX || ( checkedPixels[y, rightLineEdge] ) || ( !CheckRGBPixel( ptr ) ) ) )
            {
                // sum value of the current pixel
                meanR += ptr[RGB.R];
                meanG += ptr[RGB.G];
                meanB += ptr[RGB.B];
                pixelsCount++;
                // mark the pixel as checked
                checkedPixels[y, rightLineEdge] = true;

                rightLineEdge++;
                ptr += 3;
            }
            rightLineEdge--;


            // loop to go up and down
            ptr = (byte*) CoordsToPointerRGB( leftLineEdge, y );
            for ( int i = leftLineEdge; i <= rightLineEdge; i++, ptr += 3 )
            {
                // go up
                if ( ( y > startY ) && ( !checkedPixels[y - 1, i] ) && ( CheckRGBPixel( ptr - stride ) ) )
                    LinearFloodFill4RGB( i, y - 1 );
                // go down
                if ( ( y < stopY ) && ( !checkedPixels[y + 1, i] ) && ( CheckRGBPixel( ptr + stride ) ) )
                    LinearFloodFill4RGB( i, y + 1 );
            }
        }