Question

我正在尝试在FPS统一游戏中对系统进行编程，其中每当您耗尽12枚子弹时，该程序就会从库存堆中提取另外12枚。问题是，如果库存堆大于12，而您耗尽了已经装入枪支的12发子弹，则整个库存就会消失。我已经扫描了我的代码，并对如何解决此错误感到完全困惑。该操作的主要代码如下。

if (bulletsLeft <= 1) 
{
    if (extraBullets > 0)
    {
        if (extraBullets <= 12)
            bulletsLeft += extraBullets;

        extraBullets -= extraBullets;
    }

    if (extraBullets >= 12)
    {
        bulletsLeft += 12;
        extraBullets -= 12;
    }
}

Answer 1

因为忘记了花括号，所以您的代码...

// [[Rcpp::depends(dqrng, BH, RcppArmadillo)]]
#include <RcppArmadillo.h>
#include <boost/random/binomial_distribution.hpp>
#include <xoshiro.h>
#include <dqrng_distribution.h>
// [[Rcpp::plugins(openmp)]]
#include <omp.h>

// [[Rcpp::plugins(cpp11)]]

// [[Rcpp::export]]
arma::mat parallel_random_matrix(int n, int m, int ncores, double p=0.5) {
  dqrng::xoshiro256plus rng(42);
  arma::mat out(n*m,3);
  // ok to use rng here
#pragma omp parallel num_threads(ncores)
{
  dqrng::xoshiro256plus lrng(rng);      // make thread local copy of rng 
  lrng.jump(omp_get_thread_num() + 1);  // advance rng by 1 ... ncores jumps 
  int iter = 0;
#pragma omp for
  for (int i = 0; i < m; ++i) {
    for (int j = 0; j < n; ++j) {
      iter = i * n + j;
      // p can be a function of i and j
      boost::random::binomial_distribution<int> dist_binomial(1,p);
      auto gen_bernoulli = std::bind(dist_binomial, std::ref(lrng));
      boost::random::normal_distribution<int> dist_normal1(2.0,1.0);
      auto gen_normal1 = std::bind(dist_normal1, std::ref(lrng));
      boost::random::normal_distribution<int> dist_normal2(4.0,3.0);
      auto gen_normal2 = std::bind(dist_normal2, std::ref(lrng));
      out(iter,0) = gen_bernoulli();
      out(iter,1) = 2.0;//gen_normal1();
      out(iter,2) = 3.0;//gen_normal2();
    }
  }
}
// ok to use rng here
return out;
}

/*** R
parallel_random_matrix(5, 5, 4, 0.75)
*/

...等同于

if (extraBullets <= 12)
    bulletsLeft += extraBullets;
    extraBullets -= extraBullets;

下一条语句...

if (extraBullets <= 12) {
    bulletsLeft += extraBullets;
}
extraBullets -= extraBullets; // No more bullets after this!

...将永远不会执行。

我建议简化逻辑，并首先确定要从库存堆中转移多少发子弹。然后执行转移。

if (extraBullets >= 12)

具有三元表达式的赋值...

if (bulletsLeft <= 1) {
    int transferBullets = extraBullets < 12 ? extraBullets : 12;
    bulletsLeft += transferBullets;
    extraBullets -= transferBullets;
}

...等同于

int transferBullets = extraBullets < 12 ? extraBullets : 12;

根据@Kyle和@UnholySheep，您也可以这样写：

int transferBullets;
if (extraBullets < 12) {
    transferBullets = extraBullets;
} else {
    transferBullets = 12;
}

游戏中的弹药代码驱使我疯狂

1 个答案: