java - 在 JAVA 中使用 RadialGradientPaint 创建光

Question

我正在使用 java 开发一个简单的游戏引擎。我想在游戏中添加一些光线，并且我想使用 RadialGradientPaint。

这是我的轻量级

package engine.graphics;

import java.awt.AlphaComposite;
import java.awt.Color;
import java.awt.Graphics;
import java.awt.Graphics2D;
import java.awt.RadialGradientPaint;
import java.awt.geom.Point2D;

import engine.Main;
import engine.maths.Vector2f;

public class Light 
{
    private Vector2f pos;
    private int radius;

    public Light(Vector2f pos, int radius)
    {
        this.pos = pos;
        this.radius = radius;
    }

    public void render(Graphics g)
    {
        Graphics2D g2d = (Graphics2D)g;
        Point2D center = new Point2D.Float(pos.x, pos.y);
        float[] dist = {0.9f, 1.0f};
        Color[] color = {new Color(0.0f, 0.0f, 0.0f, 0.1f), new Color(0, 0, 0, 255)};
        RadialGradientPaint p  = new RadialGradientPaint(center, radius,  dist, color);
        g2d.setPaint(p);
        g2d.setComposite(AlphaComposite.getInstance(AlphaComposite.SRC_OVER, .95f));
        g2d.fillRect(0, 0, Main.WIDTH, Main.HEIGHT);
        g2d.dispose();
    }
}

我发现的问题是我无法绘制多于一盏灯。我怎样才能修改我的代码来制作更多的灯？谢谢..

Answer 1

我向你建议:

package solamda;

 import java.awt.BorderLayout;
 import java.awt.Color;
 import java.awt.Dimension;
 import java.awt.Graphics;
 import java.awt.Graphics2D;
 import java.awt.Point;
 import java.awt.RadialGradientPaint;
 import java.awt.geom.Point2D;

 import javax.swing.JFrame;
 import javax.swing.JLabel;

 public class Main {
    private static final Color transparency = new Color(0, 0, 0, 0);
    private static final int WIDTH = 500;
    private static final int HEIGHT = 500;

    public static void main(String[] args) {
        JFrame f = new JFrame();
        f.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        f.setMinimumSize(new Dimension(WIDTH, HEIGHT));
        f.setLayout(new BorderLayout());
        f.add(new JLabel() {
            @Override
            public void paint(Graphics g) {
                super.paint(g);
                render(g);
            }
         });

        f.pack();
         f.setVisible(true);
     }

    public static void render(Graphics g) {
         Graphics2D g2d = (Graphics2D) g;
         Point[] lights = { new Point(WIDTH / 2, HEIGHT / 2), new Point(0,0),
                new Point(WIDTH / 2+10, HEIGHT / 2), new Point(WIDTH / 2-10, HEIGHT / 2) };
         for (Point center : lights) {
             paintlight(g2d, center);
         }
        g2d.dispose();
    }

    private static void paintlight(Graphics2D g2d, Point center) {
        float[] dist = { 0.2f, 1.0f };
        Color[] color = { Color.white, transparency };
        RadialGradientPaint p = new RadialGradientPaint(center, 10, dist, color);
        g2d.setPaint(p);
        g2d.fillRect(center.x - 20, center.y - 20, 40, 40);

     }
}

您不需要仅填充整个矩形，仅填充光线所在的部分。因此，从您的代码中，我只需提取一个方法，其中 center 是一个参数(调用 Paintlight)，然后在您的方法渲染中，我可以绘制任意数量的灯光；我只是在这一点周围画了一个白色的hello，并且在画它时保持了图案的透明度