FXCellIterator
The FXCellIterator grants browse, read & write access to grid cells of a specific channel or volume.
It natively supports multiple processors so you don't have to worry about it yourself.
There are three different iterator types:
FXScalarCellIterator (for any scalar channel)
FXVectorCellIterator (for any vector channel)
FXVolumeCellIterator (for volumes)
The below definitions are displayed as if it was a class template although the specific classes are NOT accessed as a template.
It is just for convenience because all available cell iterators have the same interface definitions.
The template typenames are T and C, while T represents the datatype (double or vector3d) and C is the node type (FXScalarChannel, FXVectorChannel or FXVolume)
typename T GetValue(const int cpu)
Retrieves the value stored in the current cell.
Returns
the cell value. T is either double (FXScalarChannel, FXVolume) or vector3d (FXVectorChannel)
Parameters
const int cpu:
the current cpu thread.
typename T GetNeighborValue(const int cpu, short x, short y, short z)
Returns
the cell value of a neighboring cell. Either double (FXScalarChannel, FXVolume) or vector3d (FXVectorChannel)
Parameters
const int cpu:
the current cpu thread.
short x:
either 1 or -1 for the right or left neighbor cell respectively.
short y:
either 1 or -1 for the top or bottom neighbor cell respectively.
short z:
either 1 or -1 for the back or front neighbor cell respectively.
void SetValue(const int cpu, const typename T& value)
Overwrites the current cell's value.
Parameters
const int cpu:
the current cpu thread.
const T& value:
the new cell value. T is either double (FXScalarChannel, FXVolume) or vector3d (FXVectorChannel)
bool Init(typename C* channel)
Initialise the iterator for a specific channel and for single processor use.
Returns
true if the iterator was successfully initialised.
Parameters
C* channel:
the node to initialise the iterator for. C can be a FXScalarChannel, a FXVectorChannel or a FXVolume
depending on the type of this iterator (FXScalarCellIterator, FXVectorCellIterator or FXVolumeCellIterator respectively).
bool Init(typename C* channel, int cpus, bool include_borders = false)
Initialise the iterator for a specific channel and for multiple processor usage.
Returns
true if the iterator was successfully initialised.
Parameters
C* channel:
Pass the node to initialise the iterator for. C can be a FXScalarChannel, a FXVectorChannel or a FXVolume
depending on the type of this iterator (FXScalarCellIterator, FXVectorCellIterator or FXVolumeCellIterator respectively).
int cpus:
Pass the amount of cpu threads you will be using for iterating cells.
bool include_borders:
Specifies if you want to also browse the outermost border cells. By default it does not.
inline void Start(const int cpu, bool reverse = false)
This will reset the iterator for the given cpu.
You should call this once before browsing in a multiprocessor context.
Parameters
const int cpu:
Pass the cpu thread to reset the iterator for.
bool reverse:
Pass true if you want to reverse iterate (backwards).
inline bool SetNext(const int cpu)
Steps the iterator to get the next cell. Use for forward stepping.
Returns
true if the iterator has been incremented.
Parameters
const int cpu:
the current cpu thread to increment the iterator for.
inline bool SetPrev(const int cpu)
Steps the iterator to get the previous cell. Use for backward stepping.
Returns
true if the iterator has been decremented.
Parameters
const int cpu:
the current cpu thread to decrement the iterator for.
inline void Offset(long offset)
Offsets the iterator to a user defined position. This is only used for single processor iterations!
You need to make sure yourself the resulting iterator position is valid.
Parameters
const long offset:
the iterator cell offset.
inline void OffsetSafe(long offset)
Offsets the iterator to a user defined position. This is only used for single processor iterations!
It will make sure the iterator never falls out of range (trades of performance though).
Parameters
const long offset:
the iterator cell offset.
inline bool IsValid(void)
Returns
true if the current iterator is valid.
static FXCellIterator* Alloc()
Allocates the iterator. You can use AutoAlloc for a scope based allocation.
Works the same for FXVectorCellIterator and FXVolumeCellIterator.
Returns
the according Cell iterator. The user owns the pointed object.
static void Free(FXCellIterator*& p)
Frees a previously allocated Cell Iterator..
Parameters
FXCellIterator*&:
Pass the Cell iterator to free.