java fillarc_Java中的十字准线

我正在制作需要十字准线的游戏.我一直在玩java.awt.cursor类,这很容易,但是问题是我不希望十字准线能够离开为游戏创建的窗口,所以我尝试了以下方法：

private void drawCrossHair(Graphics g){

Ellipse2D ellipse = new Ellipse2D.Float();

ellipse.setFrame(crossHair.x, crossHair.y, 36, 36);

Color yellow = new Color (0xEDFF62);

g.setColor(yellow);

g.fillOval(crossHair.x, crossHair.y, 40, 40);

g.setClip(ellipse);

g.clip(ellipse);

基本上,我试图从“ g”中删除“椭圆”,只留下一个小环.这里的问题是“ g.clip(ellipse);”给我一个错误.我使用此代码的目的是创建一个圆心,该圆心具有透明的中心,如甜甜圈.创建甜甜圈后,我将在其内部添加一些小点,使其看起来更像十字准线.可能或可能不成问题的一件事是,我计划使用操纵杆而不是鼠标来移动十字准线…我不知道这是否会限制我的十字准线可以用作哪种对象的选择.

编辑：

这是一个SSCCE版本(几乎…由于“ g2 = bf.getDrawGraphics()”而无法编译)

package game;

import java.awt.Color;

import java.awt.Graphics2D;

import java.awt.Toolkit;

import java.awt.image.BufferStrategy;

import javax.swing.JFrame;

import java.awt.geom.Ellipse2D;

public class Game extends JFrame {

private int windowWidth = 1280;

private int windowHeight = 1024;

private Ball crossHair;

public static void main(String[] args) {

new Game();

}

public Game() {

this.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);

this.setSize(windowWidth, windowHeight);

this.setResizable(false);

this.setLocation(0,0);

this.setVisible(true);

this.createBufferStrategy(2);

initGame();

gameLoop();

}

private void initGame() {

crossHair = new Ball (windowWidth/2, windowHeight/2, 3, 3);

}

private void gameLoop() {

//game logic

drawFrame();

}

private void drawFrame() {

//Setting up Double Buffering

BufferStrategy bf = this.getBufferStrategy();

Graphics2D g2 = (Graphics2D)bf.getDrawGraphics();

try {

g2 = bf.getDrawGraphics();

Color darkBlue = new Color(0x010040);

g2.setColor(darkBlue);

g2.fillRect(0, 0, windowWidth, windowHeight);

drawCrossHair(g2);

} finally {

// dispose of graphic.

g2.dispose();

}

// show contents of backbuffer on screen

bf.show();

Toolkit.getDefaultToolkit().sync();

}

private void drawCrossHair(Graphics2D g2){

Color yellow = new Color (0xEDFF62);

g2.setColor(yellow);

g2.fillOval(crossHair.x, crossHair.y, 40, 40);

Ellipse2D ellipse = new Ellipse2D.Float();

ellipse.setFrame(crossHair.x, crossHair.y, 36, 36);

g2.setClip(ellipse);

g2.clip(ellipse);

}

}

这是同一包中的另一个类：

包装游戏；

public class Ball {

public int x;

public int y;

public int dx;

public int dy;

public Ball(int x, int y, int dx, int dy) {

this.x = x;

this.y = y;

this.dx = dx;

this.dy = dy;

}

}

编辑2：

这是我的最新尝试,这似乎可以正常工作…请告诉我这是否编码错误(我的想法是here)：

private void drawCrossHair(Graphics g){

Color yellow = new Color (0xEDFF62);

g.setColor(yellow);

for (int i = 0; i < 1; i++) {

g.drawOval(crosshair.x + i, crosshair.y + i, 40 - i - i, 40 - i - i);

}

g.fillArc(crosshair.x + 10, crosshair.y + 21 , 20, 20, -45, -90);

g.fillArc(crosshair.x - 1, crosshair.y + 10, 20, 20, -135, -90);

g.fillArc(crosshair.x + 10, crosshair.y - 1, 20, 20, -225, -90);

g.fillArc(crosshair.x + 21, crosshair.y + 10, 20, 20, -315, -90);

}