C++ - 在寻路中对 std::vector 进行排序

Question

我正在尝试在我正在开发的游戏中实现一个粗略的寻路示例。我现在需要对 std::vector<Tile*> 进行排序我尝试通过以下方法执行此操作，但出现了一堆我无法弄清楚的错误。我还尝试将 sortF 结构中的引用更改为指针，但出现另一个错误 - Comparison between pointer and integer ('Tile *' and 'int') .

有问题的错误是:No matching function for call to object of type 'Stage::sortF'

想知道我到底做错了什么。

(如果有人对寻路有任何意见，那也很好)

在 Stage.h 中公开

struct sortF
{
    bool operator()(const Tile& a, const Tile& b) const
    {
        return a.f > b.f;
    }
};

在Stage.cpp中

bool Stage::tilePath(Tile* start, Tile* end)
{
    std::vector<Tile*> path;
    std::vector<Tile*> open;
    std::vector<Tile*> closed;
    start->previousTile = start;
    start->g = 0;
    start->h = 0;
    start->f = 0;

    int i, j;
    float g, h, f;

    int sx, sy, ex, ey;

    int cost;

    Tile* current = start;
    Tile* neighbor = NULL;
    Tile* previous = NULL;
    std::cout << neighbor << std::endl;

    while(current != end) {
        sx = fmaxf(0, current->x - 1);
        sy = fmaxf(0, current->y - 1);
        ex = fminf(17 - 1, current->x + 1);
        ey = fminf(6 - 1, current->y + 1);

        for(i = sx; i <= ex; i++) {
            for(j = sy; j <= ey; j++) {
                neighbor = tiles[((j - 1) * 17) + i - 1];
                if(neighbor == current || !neighbor->walkable) continue;
                previous = current;
                if(false /* raytrace */) {

                } else {
                    cost = (current->x != neighbor->x || current->y != neighbor->y) ? 1.4 : 1;
                    g = current->g + cost;
                    h = euclidian(neighbor, end);
                    f = g + h;
                }

                if(std::find(open.begin(), open.end(), neighbor) != open.end() ||
                   std::find(closed.begin(), closed.end(), neighbor) != closed.end()) {
                    if(neighbor->f > f) {
                        neighbor->f = f;
                        neighbor->g = g;
                        neighbor->h = h;
                        neighbor->previousTile = current;
                    }
                } else {
                    neighbor->f = f;
                    neighbor->g = g;
                    neighbor->h = h;
                    neighbor->previousTile = current;
                    open.push_back(current);
                }
            }
        }

        closed.push_back(current);
        if(open.size() == 0) {
            return false;
        }
        std::sort(open.begin(), open.end(), sortF());
        current = open[0];
        std::remove(open.begin(), open.end(), 0);
    }
    return true;
}

Answer 1

^{注意:您没有包含错误消息，因此以下答案或多或少基于 View 编译:}

sortF() ，不是sortF

error: expected primary-expression before ‘)’ token
    std::sort(open.begin(), open.end(), sortF);
                                             ^

You need an instance of sortF, not the type struct sortF. Either use sortF() to create a temporary object, or use a function instead of a functor:

bool sortF(const Tile& a, const Tile& b)
{
    return a.f > b.f;
}

Tile*与 const Tile&

您使用std::sort在std::vector<Tile*>上，但是您的比较函数使用 const Tile&作为参数。要么使用std::vector<Tile>或者更正函数中的类型:

bool sortF(const Tile* a, const Tile* b)
{
    return a->f > b->f;
}