static bool sCheckPixel(const ZRef<ZDCCanvas>& inCanvas, ZDCState& ioState,
ZCoord inLocationH, ZCoord inLocationV, const ZRGBColor& inSeedColor, const ZDCRgn& inMaskRgn)
{
if (inMaskRgn.Contains(inLocationH, inLocationV))
{
// We've already visited this pixel.
return false;
}
if (inCanvas->GetPixel(ioState, inLocationH, inLocationV) != inSeedColor)
{
// This pixel is not the seed color.
return false;
}
return true;
}
static ZDCRgn sCalcFloodFillRgn(const ZRef<ZDCCanvas>& inCanvas,
ZDCState& ioState, ZPoint inSeedLocation)
{
ZDCRgn theMaskRgn;
ZRGBColor theSeedColor = inCanvas->GetPixel(ioState, inSeedLocation.h, inSeedLocation.v);
ZRect theBounds = ioState.fClip.Bounds() + (ioState.fClipOrigin - ioState.fOrigin);
vector<ZPoint> theStack;
theStack.push_back(inSeedLocation);
while (theStack.size())
{
ZPoint theLocation = theStack.back();
theStack.pop_back();
if (::sCheckPixel(inCanvas, ioState, theLocation.h, theLocation.v, theSeedColor, theMaskRgn))
{
// Find left and right boundaries
ZCoord left = theLocation.h;
while ((left > theBounds.left)
&& ::sCheckPixel(inCanvas, ioState,
left - 1, theLocation.v, theSeedColor, theMaskRgn))
{
--left;
}
ZCoord right = theLocation.h;
while ((right < theBounds.right)
&& ::sCheckPixel(inCanvas, ioState,
right, theLocation.v, theSeedColor, theMaskRgn))
{
++right;
}
theMaskRgn |= ZRect(left, theLocation.v, right, theLocation.v + 1);
// Do the line above
ZCoord currentY = theLocation.v - 1;
ZCoord currentX;
if (currentY >= theBounds.top)
{
currentX = left;
while (currentX < right)
{
while ((currentX < right)
&& !sCheckPixel(inCanvas, ioState,
currentX, currentY, theSeedColor, theMaskRgn))
{
++currentX;
}
if (currentX < right)
{
while ((currentX < right)
&& sCheckPixel(inCanvas, ioState,
currentX, currentY, theSeedColor, theMaskRgn))
{
++currentX;
}
theStack.push_back(ZPoint(currentX - 1, currentY));
}
}
}
// Do the line below
currentY = theLocation.v + 1;
if (currentY < theBounds.bottom)
{
currentX = left;
while (currentX < right)
{
while ((currentX < right)
&& !sCheckPixel(inCanvas, ioState,
currentX, currentY, theSeedColor, theMaskRgn))
{
++currentX;
}
if (currentX < right)
{
while ((currentX < right)
&& sCheckPixel(inCanvas, ioState,
currentX, currentY, theSeedColor, theMaskRgn))
{
++currentX;
}
theStack.push_back(ZPoint(currentX - 1, currentY));
}
}
}
}
}
return theMaskRgn;
}