c ++从long转换为float奇怪的错误

Question

        POINT p;
        RECT rec;

        ::GetClientRect(hWnd, &rec);
        LONG windowWidth = rec.right, windowHeight = rec.bottom;

        ::GetCursorPos(&p);//get position on screen
        ::ScreenToClient(hWnd,&p);//convert POINT to position in window

        // 2d vector math
        float x=0.0f,y=0.0f; // vector
        x= static_cast<float>(p.x - (windowWidth>>1)); // problem...
        y= static_cast<float>(p.y - (windowHeight>>1));

        char buf[100];
        sprintf_s(buf, "x: %d, y: %d\n", x,y); // create string to print
        OutputDebugStringA(buf); // print to debut window

当我向控制台打印x和y时,它给了我疯狂的数字.看起来长时间投掷会丢失一些数据,但为什么呢？不应该有任何问题.

它打印:
x:0,y:1080795136

Answer 1

 sprintf_s(buf, "x: %d, y: %d\n", x,y); 

应该

 sprintf_s(buf, "x: %f, y: %f\n", x,y); 

因为x和y有float型,不是整数.