Question

以下功能连续运行：

void MyClass::handleTriggered(float dt)
{
    // dt is time interval (period) between current call to this function and previous one
}

dt类似于0.0166026秒（每秒60帧）。

我打算每0.25秒执行一次操作。目前，我使用的事实是我们每秒60帧，即函数调用每秒发生60次：

    static long int callCount = 0;
    ++callCount;
    // Since we are going with 60 fps, then 15 calls is 1/4 i.e. 0.25 seconds
    if (callCount % 15 == 0)
        // Do something every 0.25 seconds (every 15 calls)

现在，我想知道如何使用float类型而不是int类型进行另一种操作：

    static float sumPeriod = 0.0;
    // Total time elapsed so far
    sumPeriod += dt;
    if (/* How to compose the condition? */) {
        // Every 0.25 seconds do something
    }

Answer 1

您必须将dt的总和相加，当它们达到0.25时，您需要从总和中减去0.25来做您的事情。

static float sum = 0.0;
sum += dt;
if(sum > 0.25) {
    sum -= 0.25;
    // Do what you want to do every 0.25 secs here.
}

Answer 2

static float sumPeriod = 0.0;
// Total time elapsed so far
sumPeriod += dt;
if (sumPeriod > 0.25) {
    sumPeriod -= 0.25 * int(sumPeriod / 0.25);
    // Every 0.25 seconds do something
}

每0.25秒执行一次操作

2 个答案: