为什么程序增加了 x 和 y 的值，即使它们更大了，那么它们应该是？

Question

我正在制作一个程序，它移动一个点，从 startx, starty 到 endx, endy。但它连续移动，即使在 x 和 y 大于 endx 和 endy 之后。这是代码：

int x, y;
            x = startx; y = starty;
            if(startx<goalx){
                if (starty < goaly) {
                    while (startx < goalx || starty < goaly) {
                        x += sqrt(2)*speedx;
                        y += sqrt(2)*speedy;
                    }
                }
                else {
                    while (startx < goalx || starty > goaly) {
                        x += sqrt(2)*speedx;
                        y -= sqrt(2)*speedy;
                    }
                }
            }
            else {
                if (starty < goaly) {
                    while (startx > goalx || starty < goaly) {
                        x -= sqrt(2)*speedx;
                        y += sqrt(2)*speedy;
                    }
                }
                else {
                    while (startx > goalx || starty > goaly) {
                        x -= sqrt(2)*speedx;
                        y -= sqrt(2)*speedy;
                    }
                }


            }
            cout << x << ", " << y << endl;

startx、starty、goalx 和 goaly 是用户输入。

Answer 1

控制结构取决于 startx 和 starty，但它们永远不会改变。应该使用 x 和 y 代替。

Answer 2

试试这个

int x, y;
    x = startx; y = starty;
    int xInc = sqrt(2) * speedx;
    int yInc = sqrt(2) * speedy;
    if(x < goalx && y < goaly)
    {
        while(x < goalx || y < goaly)
        {
            x += xInc;
            y += yInc;
        }
    }
    else if(x < goalx && y > goaly)
    {
        while(x < goalx || y > goaly)
        {
            x += xInc;
            y -= yInc;
        }
    }
    else if(x > goalx && y < goaly)
    {
        while(x > goalx || y < goaly)
        {
            x -= xInc;
            y += yInc;
        }
    }
    else if(x > goalx && y > goaly)
    {
        while(x > goalx || y > goaly)
        {
            x -= xInc;
            y -= yInc;
        }
    }

为什么程序增加了 x 和 y 的值，即使它们更大了，那么它们应该是？

Why does the program increase the value of the x and the y even after they are bigger, then they should be?

c++

move

infinity

coordinates