public unsafe static void FillStencilByColor(ImageSurface surface, IBitVector2D stencil, ColorBgra cmp, int tolerance,
out Rectangle boundingBox, Gdk.Region limitRegion, bool limitToSelection)
{
int top = int.MaxValue;
int bottom = int.MinValue;
int left = int.MaxValue;
int right = int.MinValue;
Gdk.Rectangle[] scans;
stencil.Clear(false);
if (limitToSelection)
{
using (Gdk.Region excluded = Gdk.Region.Rectangle(new Gdk.Rectangle(0, 0, stencil.Width, stencil.Height))) {
excluded.Xor(limitRegion);
scans = excluded.GetRectangles();
}
}
else
{
scans = new Gdk.Rectangle[0];
}
foreach (Gdk.Rectangle rect in scans)
{
stencil.Set(rect, true);
}
Parallel.For(0, surface.Height, y =>
{
bool foundPixelInRow = false;
ColorBgra *ptr = surface.GetRowAddressUnchecked(y);
int surfaceWidth = surface.Width;
for (int x = 0; x < surfaceWidth; ++x)
{
if (CheckColor(cmp, *ptr, tolerance))
{
stencil.SetUnchecked(x, y, true);
if (x < left)
{
left = x;
}
if (x > right)
{
right = x;
}
foundPixelInRow = true;
}
++ptr;
}
if (foundPixelInRow)
{
if (y < top)
{
top = y;
}
if (y >= bottom)
{
bottom = y;
}
}
});
foreach (Gdk.Rectangle rect in scans)
{
stencil.Set(rect, false);
}
boundingBox = new Rectangle(left, top, right - left + 1, bottom - top + 1);
}
public unsafe static void FillStencilFromPoint(ImageSurface surface, IBitVector2D stencil, Point start, int tolerance,
out Rectangle boundingBox, Gdk.Region limitRegion, bool limitToSelection)
{
ColorBgra cmp = surface.GetColorBgra(start.X, start.Y);
int top = int.MaxValue;
int bottom = int.MinValue;
int left = int.MaxValue;
int right = int.MinValue;
Gdk.Rectangle[] scans;
stencil.Clear(false);
if (limitToSelection)
{
using (Gdk.Region excluded = Gdk.Region.Rectangle(new Gdk.Rectangle(0, 0, stencil.Width, stencil.Height))) {
excluded.Xor(limitRegion);
scans = excluded.GetRectangles();
}
}
else
{
scans = new Gdk.Rectangle[0];
}
foreach (Gdk.Rectangle rect in scans)
{
stencil.Set(rect, true);
}
Queue <Point> queue = new Queue <Point> (16);
queue.Enqueue(start);
while (queue.Count > 0)
{
Point pt = queue.Dequeue();
ColorBgra *rowPtr = surface.GetRowAddressUnchecked(pt.Y);
int localLeft = pt.X - 1;
int localRight = pt.X;
while (localLeft >= 0 &&
!stencil.GetUnchecked(localLeft, pt.Y) &&
CheckColor(cmp, rowPtr[localLeft], tolerance))
{
stencil.SetUnchecked(localLeft, pt.Y, true);
--localLeft;
}
int surfaceWidth = surface.Width;
while (localRight < surfaceWidth &&
!stencil.GetUnchecked(localRight, pt.Y) &&
CheckColor(cmp, rowPtr[localRight], tolerance))
{
stencil.SetUnchecked(localRight, pt.Y, true);
++localRight;
}
++localLeft;
--localRight;
Action <int> checkRow = (row) =>
{
int sleft = localLeft;
int sright = localLeft;
ColorBgra *otherRowPtr = surface.GetRowAddressUnchecked(row);
for (int sx = localLeft; sx <= localRight; ++sx)
{
if (!stencil.GetUnchecked(sx, row) &&
CheckColor(cmp, otherRowPtr[sx], tolerance))
{
++sright;
}
else
{
if (sright - sleft > 0)
{
queue.Enqueue(new Point(sleft, row));
}
++sright;
sleft = sright;
}
}
if (sright - sleft > 0)
{
queue.Enqueue(new Point(sleft, row));
}
};
if (pt.Y > 0)
{
checkRow(pt.Y - 1);
}
if (pt.Y < surface.Height - 1)
{
checkRow(pt.Y + 1);
}
if (localLeft < left)
{
left = localLeft;
}
if (localRight > right)
{
right = localRight;
}
if (pt.Y < top)
{
top = pt.Y;
}
if (pt.Y > bottom)
{
bottom = pt.Y;
}
}
foreach (Gdk.Rectangle rect in scans)
{
stencil.Set(rect, false);
}
boundingBox = new Rectangle(left, top, right - left + 1, bottom - top + 1);
}