//Note from Blake:
//Iustus wrote this function, it ensures that a new river actually
//creates fresh water on the passed plot. Quite useful really
//Altouh I veto'd it's use since I like that you don't always
//get fresh water starts.
// pFreshWaterPlot = the plot we want to give a fresh water river
//
bool CvMapGenerator::addRiver(CvPlot* pFreshWaterPlot)
{
FAssertMsg(pFreshWaterPlot != NULL, "NULL plot parameter");
// cannot have a river flow next to water
if (pFreshWaterPlot->isWater())
{
return false;
}
// if it already has a fresh water river, then success! we done
if (pFreshWaterPlot->isRiver())
{
return true;
}
bool bSuccess = false;
// randomize the order of directions
std::vector<int> aiShuffle(NUM_CARDINALDIRECTION_TYPES);
GC.getGameINLINE().getMapRand().shuffleSequence(aiShuffle, NULL);
// make two passes, once for each flow direction of the river
int iNWFlowPass = GC.getGameINLINE().getMapRandNum(2, "addRiver");
for (int iPass = 0; !bSuccess && iPass <= 1; iPass++)
{
// try placing a river edge in each direction, in random order
for (int iI = 0; !bSuccess && iI < NUM_CARDINALDIRECTION_TYPES; iI++)
{
CardinalDirectionTypes eRiverDirection = NO_CARDINALDIRECTION;
CvPlot *pRiverPlot = NULL;
switch (aiShuffle[iI])
{
case CARDINALDIRECTION_NORTH:
if (iPass == iNWFlowPass)
{
pRiverPlot = plotDirection(pFreshWaterPlot->getX_INLINE(), pFreshWaterPlot->getY_INLINE(), DIRECTION_NORTH);
eRiverDirection = CARDINALDIRECTION_WEST;
}
else
{
pRiverPlot = plotDirection(pFreshWaterPlot->getX_INLINE(), pFreshWaterPlot->getY_INLINE(), DIRECTION_NORTHWEST);
eRiverDirection = CARDINALDIRECTION_EAST;
}
break;
case CARDINALDIRECTION_EAST:
if (iPass == iNWFlowPass)
{
pRiverPlot = pFreshWaterPlot;
eRiverDirection = CARDINALDIRECTION_NORTH;
}
else
{
pRiverPlot = plotDirection(pFreshWaterPlot->getX_INLINE(), pFreshWaterPlot->getY_INLINE(), DIRECTION_NORTH);
eRiverDirection = CARDINALDIRECTION_SOUTH;
}
break;
case CARDINALDIRECTION_SOUTH:
if (iPass == iNWFlowPass)
{
pRiverPlot = pFreshWaterPlot;
eRiverDirection = CARDINALDIRECTION_WEST;
}
else
{
pRiverPlot = plotDirection(pFreshWaterPlot->getX_INLINE(), pFreshWaterPlot->getY_INLINE(), DIRECTION_WEST);
eRiverDirection = CARDINALDIRECTION_EAST;
}
break;
case CARDINALDIRECTION_WEST:
if (iPass == iNWFlowPass)
{
pRiverPlot = plotDirection(pFreshWaterPlot->getX_INLINE(), pFreshWaterPlot->getY_INLINE(), DIRECTION_WEST);
eRiverDirection = CARDINALDIRECTION_NORTH;
}
else
{
pRiverPlot = plotDirection(pFreshWaterPlot->getX_INLINE(), pFreshWaterPlot->getY_INLINE(), DIRECTION_NORTHWEST);
eRiverDirection = CARDINALDIRECTION_SOUTH;
}
break;
default:
FAssertMsg(false, "invalid cardinal direction");
}
if (pRiverPlot != NULL && !pRiverPlot->hasCoastAtSECorner())
{
// try to make the river
doRiver(pRiverPlot, eRiverDirection, eRiverDirection, -1);
// if it succeeded, then we will be a river now!
if (pFreshWaterPlot->isRiver())
{
bSuccess = true;
}
}
}
}
return bSuccess;
}
// pStartPlot = the plot at whose SE corner the river is starting
//
void CvMapGenerator::doRiver(CvPlot *pStartPlot, CardinalDirectionTypes eLastCardinalDirection, CardinalDirectionTypes eOriginalCardinalDirection, int iThisRiverID)
{
if (iThisRiverID == -1)
{
iThisRiverID = GC.getMapINLINE().getNextRiverID();
GC.getMapINLINE().incrementNextRiverID();
}
int iOtherRiverID = pStartPlot->getRiverID();
if (iOtherRiverID != -1 && iOtherRiverID != iThisRiverID)
{
return; // Another river already exists here; can't branch off of an existing river!
}
CvPlot *pRiverPlot = NULL;
CvPlot *pAdjacentPlot = NULL;
CardinalDirectionTypes eBestCardinalDirection = NO_CARDINALDIRECTION;
if (eLastCardinalDirection==CARDINALDIRECTION_NORTH)
{
pRiverPlot = pStartPlot;
if (pRiverPlot == NULL)
{
return;
}
pAdjacentPlot = plotCardinalDirection(pRiverPlot->getX_INLINE(), pRiverPlot->getY_INLINE(), CARDINALDIRECTION_EAST);
if ((pAdjacentPlot == NULL) || pRiverPlot->isWOfRiver() || pRiverPlot->isWater() || pAdjacentPlot->isWater())
{
return;
}
pStartPlot->setRiverID(iThisRiverID);
pRiverPlot->setWOfRiver(true, eLastCardinalDirection);
pRiverPlot = plotCardinalDirection(pRiverPlot->getX_INLINE(), pRiverPlot->getY_INLINE(), CARDINALDIRECTION_NORTH);
}
else if (eLastCardinalDirection==CARDINALDIRECTION_EAST)
{
pRiverPlot = plotCardinalDirection(pStartPlot->getX_INLINE(), pStartPlot->getY_INLINE(), CARDINALDIRECTION_EAST);
if (pRiverPlot == NULL)
{
return;
}
pAdjacentPlot = plotCardinalDirection(pRiverPlot->getX_INLINE(), pRiverPlot->getY_INLINE(), CARDINALDIRECTION_SOUTH);
if ((pAdjacentPlot == NULL) || pRiverPlot->isNOfRiver() || pRiverPlot->isWater() || pAdjacentPlot->isWater())
{
return;
}
pStartPlot->setRiverID(iThisRiverID);
pRiverPlot->setNOfRiver(true, eLastCardinalDirection);
}
else if (eLastCardinalDirection==CARDINALDIRECTION_SOUTH)
{
pRiverPlot = plotCardinalDirection(pStartPlot->getX_INLINE(), pStartPlot->getY_INLINE(), CARDINALDIRECTION_SOUTH);
if (pRiverPlot == NULL)
{
return;
}
pAdjacentPlot = plotCardinalDirection(pRiverPlot->getX_INLINE(), pRiverPlot->getY_INLINE(), CARDINALDIRECTION_EAST);
if ((pAdjacentPlot == NULL) || pRiverPlot->isWOfRiver() || pRiverPlot->isWater() || pAdjacentPlot->isWater())
{
return;
}
pStartPlot->setRiverID(iThisRiverID);
pRiverPlot->setWOfRiver(true, eLastCardinalDirection);
}
else if (eLastCardinalDirection==CARDINALDIRECTION_WEST)
{
pRiverPlot = pStartPlot;
if (pRiverPlot == NULL)
{
return;
}
pAdjacentPlot = plotCardinalDirection(pRiverPlot->getX_INLINE(), pRiverPlot->getY_INLINE(), CARDINALDIRECTION_SOUTH);
if ((pAdjacentPlot == NULL) || pRiverPlot->isNOfRiver() || pRiverPlot->isWater() || pAdjacentPlot->isWater())
{
return;
}
pStartPlot->setRiverID(iThisRiverID);
pRiverPlot->setNOfRiver(true, eLastCardinalDirection);
pRiverPlot = plotCardinalDirection(pRiverPlot->getX_INLINE(), pRiverPlot->getY_INLINE(), CARDINALDIRECTION_WEST);
}
else
{
//FAssertMsg(false, "Illegal direction type");
// River is starting here, set the direction in the next step
pRiverPlot = pStartPlot;
long result = 0;
if (gDLL->getPythonIFace()->pythonGetRiverStartCardinalDirection(pRiverPlot, &result) && !gDLL->getPythonIFace()->pythonUsingDefaultImpl()) // Python override
{
if (result >= 0)
{
eBestCardinalDirection = ((CardinalDirectionTypes)result);
}
else
{
FAssertMsg(false, "python pythonGetRiverStartCardinalDirection() must return >= 0");
}
}
}
if (pRiverPlot == NULL)
{
return; // The river has flowed off the edge of the map. All is well.
}
else if (pRiverPlot->hasCoastAtSECorner())
{
return; // The river has flowed into the ocean. All is well.
}
if (eBestCardinalDirection == NO_CARDINALDIRECTION)
{
int iBestValue = MAX_INT;
for (int iI = 0; iI < NUM_CARDINALDIRECTION_TYPES; iI++)
{
if (getOppositeCardinalDirection((CardinalDirectionTypes)iI) != eOriginalCardinalDirection)
{
if (getOppositeCardinalDirection((CardinalDirectionTypes)iI) != eLastCardinalDirection)
{
CvPlot* pAdjacentPlot;
pAdjacentPlot = plotCardinalDirection(pRiverPlot->getX_INLINE(), pRiverPlot->getY_INLINE(), ((CardinalDirectionTypes)iI));
if (pAdjacentPlot != NULL)
{
int iValue = getRiverValueAtPlot(pAdjacentPlot);
if (iValue < iBestValue)
{
iBestValue = iValue;
eBestCardinalDirection = (CardinalDirectionTypes)iI;
}
}
}
}
}
}
if (eBestCardinalDirection != NO_CARDINALDIRECTION)
{
if (eOriginalCardinalDirection == NO_CARDINALDIRECTION)
{
eOriginalCardinalDirection = eBestCardinalDirection;
}
doRiver(pRiverPlot, eBestCardinalDirection, eOriginalCardinalDirection, iThisRiverID);
}
}
