Java mandelbrot set移动错误

Question

所以我一直在尝试在java中编程mandelbrot集，我知道代码不是很优化，但我刚刚开始这样做。

这个想法是，当我点击一个像素，它会把像素在中心(代表一个特定的复数)，并计算它周围的集合。这在开始工作，但如果我放大它会开始表现得很奇怪。我猜这是我的midX, midY或显示功能，这是奇怪的，但我一直在看它很长一段时间，不能弄清楚，将感谢一些帮助。

class set {
    DotWindow w;
    int[][] arrayColor;
    int max = 100;
    Grayscale gray;
    double zoom = 1.1;
    double midX = -0.5;
    double midY = 0;
    public static void main(String[] args) {
        new set().run();
    }
    void run() {
        setup();
        runLoop();
    }
    void runLoop() {
        int x;
        int y;
        while (true) {
            GameEvent event = w.getNextEvent();
            switch (event.getKind()) {
            case GameEvent.KEY_PRESSED:
                int key = event.getKey();
                if (key == 43) {
                    zoom = zoom * 1.1;
                } else if (key == 45) {
                    zoom = zoom / 1.1;
                }
                display();
                break;
            case GameEvent.MOUSE_CLICKED:
                midX = midX - (1 - event.getX() / 250.0);
                midY = midY - (1 - event.getY() / 250.0);
                System.out.println(midX);
                display();
                break;
            }
        }
    }
    void setup() {
        w = new DotWindow(500, 500, 1);
        w.checkMouse(true, false, false, false, false);
        w.checkKeys(true, false, false);
        arrayColor = new int[500][500];
        zoom = zoom / 1.1;
        display();
    }
    int calculate(double re, double im) {
        double Zre = 0;
        double Zim = 0;
        double Zim2 = 0;
        double Zre2 = 0;
        int iterations = 0;
        for (int k = 0; k < max; k++) {
            if (Zre2 + Zim2 > 4.0) {
                return k;
            }
            Zim2 = Zim * Zim;
            Zre2 = Zre * Zre;
            Zim = 2.0 * Zre * Zim + im;
            Zre = Zre2 - Zim2 + re;
            iterations = k;
        }
        return iterations;
    }
    void display() {
        for (double y = 0; y < 500; y++) {
            for (double x = 0; x < 500; x++) {
                double value = calculate((midX - (1 - x / 250) / zoom),
                        (midY - (1 - y / 250) / zoom));
                if (value == 99) {
                    w.setDot((int) x, (int) y, Color.BLACK);
                } else {
                    w.setDot((int) x, (int) y, gray = new Grayscale(
                            255 - (int) value * 2));
                }
            }
        }
    }
}

Answer 1

        case GameEvent.MOUSE_CLICKED:
            midX = midX - (1 - event.getX() / 250.0)/zoom;
            midY = midY - (1 - event.getY() / 250.0)/zoom;
            System.out.println(midX);
            display();

你已经放大了，比如说放大到10倍，但是你改变了中心坐标，而不考虑缩放值