I am following a tutorial on creating a hexagon map for a game. The source has it in struct, but I want it to be a class and so far I am unable to make it work. It compiles fine, but when I try to insert a new value in it, it segfaults. I am probably doing the hash function wrong, or something, but I have ran out of ideas on fixing it. Thanks!
main.c
#include <unordered_set>
#include "hexagonField.hpp"
int main(int argc, char **argv)
{
std::unordered_set <HexagonField> map;
map.insert(HexagonField(0, 0, 0));
return 0;
}
hexagonField.hpp
#ifndef HEXAGON_H
#define HEXAGON_H
#include <assert.h>
#include <vector>
class HexagonField
{
public:
const int q, r, s;
HexagonField(int q, int r, int s);
~HexagonField();
HexagonField hexagonAdd(HexagonField a, HexagonField b);
HexagonField hexagonSubtract(HexagonField a, HexagonField b);
HexagonField hexagonMultiply(HexagonField a, int k);
int hexagonLength(HexagonField hex);
int hexagonDistance(HexagonField a, HexagonField b);
HexagonField hexagonDirection(int direction /* 0 to 5 */);
HexagonField hexagonNeighbor(HexagonField hex, int direction);
const std::vector<HexagonField> hexagonDirections = {
HexagonField(1, 0, -1), HexagonField(1, -1, 0), HexagonField(0, -1, 1),
HexagonField(-1, 0, 1), HexagonField(-1, 1, 0), HexagonField(0, 1, -1)
};
bool operator == (const HexagonField comparedHex) const
{
return this->q == comparedHex.q && this->r == comparedHex.r && this->s == comparedHex.s;
}
bool operator != (const HexagonField comparedHex) const
{
return !(*this == comparedHex);
};
};
namespace std
{
template<>
struct hash<HexagonField>
{
size_t operator()(const HexagonField & obj) const
{
return hash<int>()(obj.q);
}
};
}
#endif
hexagonField.cpp
#include "hexagonField.hpp"
HexagonField::HexagonField(int q, int r, int s): q(q), r(r), s(s)
{
assert (q r s == 0);
}
HexagonField HexagonField::hexagonAdd(HexagonField a, HexagonField b)
{
return HexagonField(a.q b.q, a.r b.r, a.s b.s);
}
HexagonField HexagonField::hexagonSubtract(HexagonField a, HexagonField b)
{
return HexagonField(a.q - b.q, a.r - b.r, a.s - b.s);
}
HexagonField HexagonField::hexagonMultiply(HexagonField a, int k)
{
return HexagonField(a.q * k, a.r * k, a.s * k);
}
int HexagonField::hexagonLength(HexagonField hex) {
return int((abs(hex.q) abs(hex.r) abs(hex.s)) / 2);
}
int HexagonField::hexagonDistance(HexagonField a, HexagonField b) {
return hexagonLength( hexagonSubtract(a, b));
}
HexagonField HexagonField::hexagonDirection(int direction /* 0 to 5 */) {
assert (0 <= direction && direction < 6);
return hexagonDirections[direction];
}
HexagonField HexagonField::hexagonNeighbor(HexagonField hex, int direction) {
return hexagonAdd(hex, hexagonDirection(direction));
}
CodePudding user response:
If you run your program under a debugger, you will see it actually overflowed the stack while trying to construct HexagonField objects. This is because every object has a vector of 6 more HexagonField objects, which in turn needs another vector, and so on.
As a quick fix, you can take hexagonDirections
out of the HexagonField
class and move it to a static file-scoped variable at the top of HexagonField.cpp instead:
static const std::vector<HexagonField> hexagonDirections = {
HexagonField(1, 0, -1), HexagonField(1, -1, 0), HexagonField(0, -1, 1),
HexagonField(-1, 0, 1), HexagonField(-1, 1, 0), HexagonField(0, 1, -1)
};
Alternatively, you can leave hexagonDirections
as a static class member and move the definition to your .cpp file:
// HexagonField.h
class HexagonField {
...
static const std::vector<HexagonField> hexagonDirections;
...
};
// HexagonField.cpp
const std::vector<HexagonField> HexagonField::hexagonDirections = {
HexagonField(1, 0, -1), HexagonField(1, -1, 0), HexagonField(0, -1, 1),
HexagonField(-1, 0, 1), HexagonField(-1, 1, 0), HexagonField(0, 1, -1)
};