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java - java - Graphics2D 渲染太慢？

问题描述

我正在为能够改变角度、填充颜色、线条颜色、线条粗细的矩形制作一个类。并且矩形将以这种方式呈现。我决定做一个小检查。在检查过程中，我发现矩形渲染太慢了。我可以看到它们是从上到下渲染的。可能是什么原因？

G编辑

import javax.swing.*;

public class GEdit {
    public static void main(String[] args)
    {
        frame app = new frame();
        app.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        app.setSize(1000,1000);
        app.setVisible(true);
    }
}

图.java

import java.awt.*;
import java.awt.geom.Point2D;

public abstract class Figure
{
    public static final int TOPLEFT = 0;
    public static final int TOPCENTER = 1;
    public static final int TOPRIGHT = 2;
    public static final int CENTERLEFT = 3;
    public static final int CENTER = 4;
    public static final int CENTERRIGHT = 5;
    public static final int BOTTOMLEFT = 6;
    public static final int BOTTOMCENTER = 7;
    public static final int BOTTOMRIGHT = 8;

    private boolean fill_able;
    private int fill_option;
    private Color fill_color;
    private int fill_transparency;

    private Color line_color;
    private float line_thickness;
    private int line_transparency;

    private int width;
    private int height;
    private float rotate_angle;

    private boolean width_height_ratio_fixed;

    private Point location;
    private int base;

    public Figure(boolean fill_able,
                  int fill_option,
                  Color fill_color,
                  int fill_transparency,
                  Color line_color,
                  float line_thickness,
                  int line_transparency,
                  int width, int height,
                  float rotate_angle,
                  boolean width_height_ratio_fixed,
                  int x, int y,
                  int base)
    {
        this.fill_able = fill_able;
        this.fill_option = fill_option;
        this.fill_color = fill_color;
        this.fill_transparency = fill_transparency;
        this.line_color = line_color;
        this.line_thickness = line_thickness;
        this.line_transparency = line_transparency;
        this.width = width;
        this.height = height;
        this.rotate_angle = rotate_angle;
        this.width_height_ratio_fixed = width_height_ratio_fixed;
        this.location = new Point(x,y);
        this.base = base;
    }

    public boolean is_fill_able()
    {
        return fill_able;
    }

    public int get_fill_option()
    {
        return fill_option;
    }

    public Color get_fill_color()
    {
        return fill_color;
    }

    public int get_fill_transparency()
    {

        return fill_transparency;
    }

    public Color get_line_color()
    {
        return line_color;
    }

    public float get_line_thickness()
    {
        return line_thickness;
    }

    public int get_line_transparency()
    {
        return line_transparency;
    }

    public int get_width()
    {
        return width;
    }

    public int get_height()
    {
        return height;
    }

    public float get_rotate_angle()
    {
        return rotate_angle;
    }

    public boolean is_width_height_ratio_fixed()
    {
        return width_height_ratio_fixed;
    }

    public Point get_location()
    {
        return location;
    }

    public Point get_render_location()
    {
        int x, y;

        switch(base)
        {
            case TOPLEFT:
                x = location.x;
                y = location.y;
                break;
            case TOPCENTER:
                x = location.x - (int)Math.round(width / 2);
                y = location.y;
                break;
            case TOPRIGHT:
                x = location.x - width;
                y = location.y;
                break;
            case CENTERLEFT:
                x = location.x;
                y = location.y - (int)Math.round(height / 2);
                break;
            case CENTER:
                x = location.x - (int)Math.round(width / 2);
                y = location.y - (int)Math.round(height / 2);
                break;
            case CENTERRIGHT:
                x = location.x - width;
                y = location.y - (int)Math.round(height / 2);
                break;
            case BOTTOMLEFT:
                x = location.x;
                y = location.y - height;
                break;
            case BOTTOMCENTER:
                x = location.x - (int)Math.round(width / 2);
                y = location.y - height;
                break;
            case BOTTOMRIGHT:
                x = location.x - width;
                y = location.y - height;
                break;
            default:
                x = 0; y = 0;
                break;
        }

        return new Point(x, y);
    }

    public int get_base()
    {
        return base;
    }

    public void set_fill_option(int option)
    {
        this.fill_option = option;
    }

    public void set_fill_color(Color color)
    {
        this.fill_color = color;
    }

    public void set_fill_transparency(int transparency)
    {
        this.fill_transparency = transparency;
    }

    public void set_line_color(Color color)
    {
        this.line_color = color;
    }

    public void set_line_transparency(int transparency)
    {
        this.line_transparency = transparency;
    }

    public void set_width(int width)
    {
        if(this.width_height_ratio_fixed)
        {
            float ratio = this.height / this.width;
            this.width = width;
            this.height = (int)Math.round(width * ratio);
        }
        else { this.width = width;}
    }

    public void set_height(int height)
    {
        if(this.width_height_ratio_fixed)
        {
            float ratio = this.width / this.height;
            this.height = height;
            this.width = (int)Math.round(height * ratio);
        }
        else{ this.height = height;}
    }

    public void set_rotate_angle(float angle)
    {
        if(angle > 360)
        {
            this.rotate_angle = angle % 360;
        }
        else this.rotate_angle = angle;
    }

    public void set_location(int x, int y)
    {
        this.location.setLocation(x, y);
    }

    public void set_location(Point location)
    {
        this.location = location;
    }

    public void set_base(int base)
    {
        this.base = base;
    }

    abstract public void render(Graphics2D g);
}

矩形.java

import java.awt.*;
import java.awt.Graphics2D;
import java.awt.geom.*;

public class Rectangle extends Figure {

    public Rectangle(Color fill_color, Color line_color, float line_thickness, int width, int height, int x, int y)
    {
        super(true,
                0,
                fill_color,
                255,
                line_color,
                line_thickness,
                255,
                width, height,
                0,
                false,
                x, y,
                TOPLEFT);
    }

    public void render(Graphics2D g)
    {
        Rectangle2D rectangle = new Rectangle2D.Float(get_width(),get_height(),get_render_location().x,get_render_location().y);

        g.rotate(Math.toRadians(get_rotate_angle()),rectangle.getCenterX(),rectangle.getCenterY());

        if(is_fill_able())
        {
            Color color = new Color(
                    get_fill_color().getRed(),
                    get_fill_color().getGreen(),
                    get_fill_color().getBlue(),
                    get_fill_transparency());
            g.setColor(color);
            g.fill(rectangle);
        }

        Stroke old_stroke = g.getStroke();
        g.setStroke(new BasicStroke(get_line_thickness()));

        Color line_color = new Color(
                get_line_color().getRed(),
                get_line_color().getGreen(),
                get_line_color().getBlue(),
                get_line_transparency());
        g.setColor(line_color);
        g.draw(rectangle);

        g.setStroke(old_stroke);
        g.rotate(Math.toRadians(get_rotate_angle() * -1),rectangle.getCenterX(),rectangle.getCenterY());
    }
}

框架.java

import javax.print.DocFlavor;
import javax.swing.JFrame;
import java.awt.*;
import java.util.Random;

public class frame extends JFrame{
    public frame()
    {
        super("test");

    }

    @Override
    public void paint(Graphics g) {
        Graphics2D graphics2D = (Graphics2D)g;

        RenderingHints renderingHints1 = new RenderingHints(RenderingHints.KEY_ANTIALIASING,
                RenderingHints.VALUE_ANTIALIAS_ON);
        RenderingHints renderingHints2 = new RenderingHints(RenderingHints.KEY_RENDERING,
                RenderingHints.VALUE_RENDER_QUALITY);
        graphics2D.setRenderingHints(renderingHints1);
        graphics2D.setRenderingHints(renderingHints2);

        Random random = new Random();
        g.setColor(Color.WHITE);
        g.fillRect(0,0,1000,1000);

        for(int i =0;i < 10; i++)
        {
            Rectangle rectangle = new Rectangle(Color.CYAN,Color.BLACK,random.nextInt(10),random.nextInt(1000),random.nextInt(1000),random.nextInt(300),random.nextInt(300));
            rectangle.set_fill_transparency(random.nextInt(255));
            rectangle.set_rotate_angle(random.nextInt(180));
            rectangle.render(graphics2D);
        }
    }
}

标签： javageometryrender

解决方案

您正在覆盖方法paint，这通常是一个坏主意。

您还在计算绘制期间所需的所有信息，这是另一个坏主意：它们应该在之前计算。如果您需要 4x10 随机数，可以在绘制前计算它们并将 40 个数字存储在 int[] 数组中。

正如有人提到的，您应该使用 aJPanel和方法paintComponent。

以下链接对您来说可能是一个有趣的阅读：http: //www.billharlan.com/papers/Improving_Swing_Performance.html

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