小编典典

使用.setPaint(gradient)时调整大小时不重绘

java

一旦我在代码中使用了渐变,在调整大小时就不会完成重新绘制,而在调整大小时
会得到类似的信息(已调整大小的黑色矩形,请参见下面的链接中的图像)。当我停止调整大小时,一切都会
再次绘制,但只有那时。

如果我不使用,g2d.setPaint(gradient);我会快速重画

http://gui-builder.com/C41142775162.rar

public void paintComponent(Graphics g)  
{

        super.paintComponent(g);

        Graphics2D g2d = (Graphics2D)g;

        //sample of the code  
        GradientPaint gradient = new GradientPaint(startX, startY, greyColor1, endX, endY, new Color(120,120,120));  
        g2d.setPaint(gradient);  
        g.drawLine(i, startY, i, endY);  
}

我尝试repaint()调整大小,尝试repaint()拖动鼠标时却
什么也没有。

这是一些SSCCE(对不起,我之前没有发布过):

BufferedImage aa;

@Override  
public void paintComponent(Graphics g)  
{  
        super.paintComponent(g);

        Graphics gr = aa.getGraphics();  
        Graphics2D g2d = (Graphics2D)gr;

        g2d.setRenderingHint(RenderingHints.KEY_ANTIALIASING,  
                    RenderingHints.VALUE_ANTIALIAS_ON);


        for (int i = 0; i < this.getWidth(); i++)  
        {  
            LinearGradientPaint lgp = new LinearGradientPaint(
            new Point2D.Float(0, 0),
            new Point2D.Float(0, this.getHeight()),
            new float[] {0f, 0.5f, 1f},
            new Color[] {Color.BLUE, Color.RED, Color.BLUE}
            ); 
            g2d.setPaint(lgp);  
            gr.drawLine(i, 0, i, this.getHeight());  
        }  
        g.drawImage(aa, 0, 0, frame);  
}

并在您的构造函数中:

aa = new BufferedImage(100,100,BufferedImage.TYPE_INT_ARGB);

我仍然需要一个答案,为什么在调整窗口大小时
(同时移动窗口的调整大小角时)未完成重绘

好吧,总结一下:我尝试了Java中的三种主要绘制方法:
BufferStrategy,双Swing缓冲图像和没有图像
缓冲区的简单摆动。我发现速度更快的是最后一个(令人惊讶的)。

现在我使用的是快速的,我发现首先将窗口调整为
较小的尺寸,然后将窗口调整为较大的尺寸,该问题就会消失。
别笑,这是我的问题,那完全是个谜。这是
它的视频:C41142775162.rar

当我将尺寸调整为小尺寸时会发生什么?我不知道。但是,如果您知道任何帮助,
将不胜感激。

谢谢

我也发现最好尽可能少使用setPaint。您可以运行测试,您会发现不经常使用setPaint()会更快。例如,代替使用:

LinearGradientPaint gradient1 = new LinearGradientPaint(
        new Point2D.Float(0, 0),
        new Point2D.Float(0, 10),
        new float[] {0f, 1f},
        new Color[] {new Color(40,40,40), new Color(110,110,110)}
    );
LinearGradientPaint gradient2 = new LinearGradientPaint(
        new Point2D.Float(0, 10),
        new Point2D.Float(0, 20),
        new float[] {0f, 1f},
        new Color[] {new Color(110,110,110), new Color(190,190,190)}
    );
LinearGradientPaint gradient3 = new LinearGradientPaint(
        new Point2D.Float(0, 20),
        new Point2D.Float(0, 30),
        new float[] {0f, 1f},
        new Color[] {new Color(190,190,190), new Color(250,250,250)}
    );                        
for (int i = 0; i < this.getWidth(); i++)
{
    g2d.setPaint(gradient1);
    gr.drawLine(i, 0, i, 10);
    g2d.setPaint(gradient2);
    gr.drawLine(i, 10, i, 20);
    g2d.setPaint(gradient3);
    gr.drawLine(i, 20, i, 30);                            
}

use :

LinearGradientPaint gradient1 = new LinearGradientPaint(
        new Point2D.Float(0, 0),
        new Point2D.Float(0, 10),
        new float[] {0f, 1f},
        new Color[] {new Color(40,40,40), new Color(110,110,110)}
    );
LinearGradientPaint gradient2 = new LinearGradientPaint(
        new Point2D.Float(0, 10),
        new Point2D.Float(0, 20),
        new float[] {0f, 1f},
        new Color[] {new Color(110,110,110), new Color(190,190,190)}
    );
LinearGradientPaint gradient3 = new LinearGradientPaint(
        new Point2D.Float(0, 20),
        new Point2D.Float(0, 30),
        new float[] {0f, 1f},
        new Color[] {new Color(190,190,190), new Color(250,250,250)}
    );

g2d.setPaint(gradient1);
for (int i = 0; i < this.getWidth(); i++)
     gr.drawLine(i, 0, i, 10);

g2d.setPaint(gradient2);
for (int i = 0; i < this.getWidth(); i++)
    gr.drawLine(i, 10, i, 20);

g2d.setPaint(gradient3);
for (int i = 0; i < this.getWidth(); i++)
    gr.drawLine(i, 20, i, 30);

even if you have a lot of computations, it will be almost every time faster!


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2020-11-30

共1个答案

小编典典

我进行了测试,发现其 性能GradientPaint很差。平均渲染时间从1.2秒(400x400像素)到20多秒。

我换了GradientPaint一个LinearGradientPaint,发现渲染时间为约1.3秒而不是。

LinearGradientPaint lgp = new LinearGradientPaint(
                new Point2D.Float(0, minY),
                new Point2D.Float(0, maxY),
                new float[] {0f, 0.5f, 1f},
                new Color[] {Color.BLUE, Color.RED, Color.BLUE}
                );
g2d.setPaint(lgp);
    // Render all your samples, don't reapply or change you paint...

抱歉,我的样品不是很令人兴奋……

您可能会发现,最好改为在后台线程中渲染到后台缓冲区,并在完成后将整个图像绘制到屏幕上。这将阻止屏幕“暂停”

2020-11-30