bresenham画圆算法java

以下是用Java实现Bresenham算法画整圆的代码：

import java.awt.*;
import javax.swing.*;

public class BresenhamCircle extends JPanel {
    private int centerX, centerY, radius;
    private int[][] grid;

    public BresenhamCircle(int centerX, int centerY, int radius) {
        this.centerX = centerX;
        this.centerY = centerY;
        this.radius = radius;
        grid = new int[2 * radius + 1][2 * radius + 1];
        setPreferredSize(new Dimension(2 * radius + 1, 2 * radius + 1));
        setBackground(Color.WHITE);
        calculatePoints();
    }

    private void calculatePoints() {
        int x = 0, y = radius, d = 3 - 2 * radius;
        while (x <= y) {
            plotPoints(x, y);
            if (d < 0) {
                d = d + 4 * x + 6;
            } else {
                d = d + 4 * (x - y) + 10;
                y--;
            }
            x++;
        }
    }

    private void plotPoints(int x, int y) {
        grid[centerX + x][centerY + y] = 1;
        grid[centerX + x][centerY - y] = 1;
        grid[centerX - x][centerY + y] = 1;
        grid[centerX - x][centerY - y] = 1;
        grid[centerX + y][centerY + x] = 1;
        grid[centerX + y][centerY - x] = 1;
        grid[centerX - y][centerY + x] = 1;
        grid[centerX - y][centerY - x] = 1;
    }

    @Override
    protected void paintComponent(Graphics g) {
        super.paintComponent(g);
        int width = getWidth();
        int height = getHeight();
        int cellWidth = width / (2 * radius + 1);
        int cellHeight = height / (2 * radius + 1);
        for (int i = 0; i <= 2 * radius; i++) {
            for (int j = 0; j <= 2 * radius; j++) {
                if (grid[i][j] == 1) {
                    g.setColor(Color.BLACK);
                } else {
                    g.setColor(Color.WHITE);
                }
                g.fillRect(i * cellWidth, j * cellHeight, cellWidth, cellHeight);
                g.setColor(Color.GRAY);
                g.drawRect(i * cellWidth, j * cellHeight, cellWidth, cellHeight);
            }
        }
    }

    public static void main(String[] args) {
        JFrame frame = new JFrame("Bresenham Circle");
        frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        BresenhamCircle circle = new BresenhamCircle(100, 100, 50);
        frame.getContentPane().add(circle);
        frame.pack();
        frame.setVisible(true);
    }
}