Question

我正在做一些练习，而且我已经坚持了几个小时了（Java的新手）。无论如何，这是我应该做的：当我运行程序时，我将在屏幕中间有一个正方形，然后当我点击该屏幕中的某个位置时，将在我点击的位置绘制另一个正方形，并且在这两个点之间应该有10个正方形。所以无论我在哪里点击，都应该总是画出10个方格。

但是，我无法使其正常运作。

这是我到目前为止所做的事情：

import se.lth.cs.ptdc.window.SimpleWindow;  
import se.lth.cs.ptdc.square.Square;


public class PrintSquares2 {


public static void main(String[] args) {
    SimpleWindow w = new SimpleWindow(600, 600, "PrintSquares2");
    int posX = 300;
    int posY = 300;
    int loop = 0;
    System.out.println("Skriv rotation");
    Square sq1 = new Square(posX,posY,200);
    sq1.draw(w);


            w.waitForMouseClick();
            int destX = w.getMouseX();
            int destY = w.getMouseY();
            System.out.println("Dest X: " + destX + " Dest Y: " + destY);
            System.out.println("Pos X: " + posX + " Pos Y: " + posY);
            SimpleWindow.delay(10);
            //sq1.erase(w);
            int jumpX = (destX - posX) / 10;
            int jumpY = (destY - posY) / 10;
            System.out.println(jumpX);


                while (posX < destX)
                {       
                    posX = posX+10;
                    SimpleWindow.delay(100);
                    loop++;
                    System.out.println("Loop: " + loop);
                    System.out.println("Dest X: " + destX + " Dest Y: " + destY);
                    System.out.println("Pos X: " + posX + " Pos Y: " + posY);       
                    Square sq2 = new Square(posX,posY,200);         
                    sq2.draw(w);                        
                }

                while (posX > destX)
                {
                    posX = posX-10;
                    SimpleWindow.delay(100);
                    loop++;
                    System.out.println("Loop: " + loop);
                    System.out.println("Dest X: " + destX + " Dest Y: " + destY);
                    System.out.println("Pos X: " + posX + " Pos Y: " + posY);
                    sq1.draw(w);
                    Square sq2 = new Square(posX,posY,200);         
                    sq2.draw(w);
                }

                while (posY < destY)
                {       
                    posY = posY+10;
                    SimpleWindow.delay(100);
                    loop++;
                    System.out.println("Loop: " + loop);
                    System.out.println("Dest X: " + destX + " Dest Y: " + destY);
                    System.out.println("Pos X: " + posX + " Pos Y: " + posY);
                    sq1.draw(w);
                    Square sq2 = new Square(posX,posY,200);         
                    sq2.draw(w);
                }

                while (posY > destY)
                {
                    posY = posY-10;
                    SimpleWindow.delay(100);
                    loop++;
                    System.out.println("Loop: " + loop);
                    System.out.println("Dest X: " + destX + " Dest Y: " + destY);
                    System.out.println("Pos X: " + posX + " Pos Y: " + posY);
                    sq1.draw(w);
                    Square sq2 = new Square(posX,posY,200);         
                    sq2.draw(w);
                }


            SimpleWindow.delay(10);
            sq1.draw(w);

            //SimpleWindow.clear(w);


    }

}

我很确定我过于复杂，因为这应该是非常基本的。

最终结果应该如下所示： End result

Answer 1

这就是我解决它的方式：

我对se.lth.cs.ptdc.square.Square上的文档并不十分了解，但我会假设它根据左上角的坐标和边长来绘制一个正方形。

所以你有第一个方格左上角的坐标和最后一个方格中心的坐标。得到最后一个方格的左上角的坐标并不困难：
lastX = centerX - side/2
lastY = centerY - side/2

完成后，您会发现起点和终点之间的差异：
diffX = posX - lastX
diffY = posY - lastY

然后再抽出9个方块：

for (int i=1; i<10; i++){
    squareX = posX + (diffX/10)*i;
    squareY = posY + (diffY/10)*i;
    Square square = new Square(squareX,squareY,200);         
    square.draw(w);
}

实际上你做的第一部分是正确的，只是弄乱了那些不必要的检查。希望它有所帮助。

-
问候，svz。

Answer 2

在同一时间更新X和Y：

    int jumpX = (destX - posX) / 10;
    int jumpY = (destY - posY) / 10;
    if (posX > destX) {
        int temp = destX;
        destX = posX;
        posX = temp;
    }

    while (posX <= destX)
    {       
            SimpleWindow.delay(100);
            loop++;
            System.out.println("Loop: " + loop);
            System.out.println("Dest X: " + destX + " Dest Y: " + destY);
            System.out.println("Pos X: " + posX + " Pos Y: " + posY);       
            Square sq2 = new Square(posX,posY,200);         
            sq2.draw(w);                        
            posX = posX+jumpX;
            posY = posY+jumpY;
    }    

    SimpleWindow.delay(10);
    sq1.draw(w);

Answer 3

以下是您一次向两个方向移动的方式（在对角线上）。

static final int Steps = 10;

private void test() {
  int x1 = 100;
  int y1 = 100;
  int x2 = 300;
  int y2 = 500;

  double dx = (double)(x2 - x1) / (double) Steps;
  double dy = (double)(y2 - y1) / (double) Steps;

  double x = x1;
  double y = x2;
  for ( int i = 0; i < Steps; i++) {
    // Simulate the drawing of the square.
    System.out.println("("+x+","+y+")");
    x += dx;
    y += dy;
  }
}

在两点之间绘制正方形

3 个答案: