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javafx画布绘制与java.awt.graphics2d绘制相比

• 问答

我想显示一个相对较长的图表。我曾经使用过Javafx canvas，但是有时在绘制许多值时会出现缓冲区溢出异常。我正在寻找一种不同的方法，并找到了一种使用java.awt.graphics2d绘制图表的方法。 graphics2d的优点是性能得到了提高，而且我也没有例外。缺点是图的质量。使用graphics2d时，该图看起来不像javafx画布中的图那样平滑。

这里有两个测试应用程序（一个使用javafx canvas，一个使用java.awt.graphics2d），其中绘制了一个正弦波。

如何提高graphics2d示例的质量，使其看起来像画布示例？ 还是我没有想到过的另一种方法可以解决我的问题？

画布示例

public class CanvasDraw extends Application
{
    private static final int PANEL_WIDTH = 400,PANEL_HEIGHT = 100;


    public static void main(String[] args)
    {
        launch(args);
    }


    @Override
    public void start(Stage stage)
    {
        stage.setTitle("CanvasDraw");
        StackPane root = new StackPane();
        Scene scene = new Scene(root);
        root.getchildren().add(createCanvas());
        stage.setScene(scene);
        stage.show();
    }


    private Canvas createCanvas()
    {
        Canvas canvas = new Canvas(PANEL_WIDTH,PANEL_HEIGHT);
        GraphicsContext gc = canvas.getGraphicsContext2D();
        drawSinus(gc);
        return canvas;
    }


    private void drawSinus(GraphicsContext gc)
    {
        double height = 50;
        double xFactor = 0.5;
        double yFactor = 50;
        for (int index = 0; index < 720; index++)
        {
            double x = index * xFactor;
            double y = Math.sin(Math.toRadians(index)) * yFactor + height;
            if (index == 0)
            {
                gc.moveTo(x,y);
            }
            else
            {
                gc.lineTo(x,y);
            }
        }
        gc.stroke();
    }
}

NEW Graphics2D示例

public class Graphics2DDraw extends Application
{
    private static final int PANEL_WIDTH = 400,PANEL_HEIGHT = 100;


    public static void main(String[] args)
    {
        launch(args);
    }


    @Override
    public void start(Stage stage)
    {
        stage.setTitle("Graphics2DDraw");
        StackPane root = new StackPane();
        Scene scene = new Scene(root);
        root.getchildren().add(createImageView());
        stage.setScene(scene);
        stage.show();
    }


    private ImageView createImageView()
    {
        BufferedImage bi = new BufferedImage(PANEL_WIDTH,PANEL_HEIGHT,BufferedImage.TYPE_INT_ARGB);
        Graphics2D g = bi.createGraphics();
        g.setColor(Color.BLACK);
        BasicStroke bs = new BasicStroke(1f,BasicStroke.CAP_ROUND,BasicStroke.JOIN_ROUND);
        g.setStroke(bs);
        g.setRenderingHint(RenderingHints.KEY_ANTIALIASING,RenderingHints.VALUE_ANTIALIAS_ON);
        g.setRenderingHint(RenderingHints.KEY_RENDERING,RenderingHints.VALUE_RENDER_SPEED);
        g.setRenderingHint(RenderingHints.KEY_STROKE_CONTROL,RenderingHints.VALUE_STROKE_PURE);
        drawSinus(g);
        return new ImageView(SwingFXUtils.toFXImage(bi,null));
    }


    private void drawSinus(Graphics2D g)
    {
        double height = 50;
        double xFactor = 0.5;
        double yFactor = 50;
        int length = 720;
        int lastX = 0;
        int lastY = 0;
        GeneralPath path = new GeneralPath();
        for (int index = 0; index < length; index++)
        {
            double x3 = index * xFactor;
            double y3 = Math.sin(Math.toRadians(index)) * yFactor + height;
            if (index == 0)
            {
                path.moveTo(x3,y3);
            }
            else
            {
                path.lineTo(x3,y3);
            }
        }
        g.draw(path);
        g.dispose();
    }
}

编辑 这是缓冲区溢出异常的样子：

java.nio.BufferOverflowException
    at com.sun.javafx.sg.prism.GrowableDataBuffer.ensureReadCapacity(GrowableDataBuffer.java:317)
    at com.sun.javafx.sg.prism.GrowableDataBuffer.getInt(GrowableDataBuffer.java:527)
    at com.sun.javafx.sg.prism.GrowableDataBuffer.getFloat(GrowableDataBuffer.java:563)
    at com.sun.javafx.sg.prism.NGCanvas.renderStream(NGCanvas.java:960)
    at com.sun.javafx.sg.prism.NGCanvas.renderContent(NGCanvas.java:609)
    at com.sun.javafx.sg.prism.NGNode.doRender(NGNode.java:2053)
    at com.sun.javafx.sg.prism.NGNode.render(NGNode.java:1945)
    at com.sun.javafx.sg.prism.NGGroup.renderContent(NGGroup.java:235)
    at com.sun.javafx.sg.prism.NGRegion.renderContent(NGRegion.java:577)
    at com.sun.javafx.sg.prism.NGNode.doRender(NGNode.java:2053)
    at com.sun.javafx.sg.prism.NGNode.render(NGNode.java:1945)
    at com.sun.javafx.sg.prism.NGGroup.renderContent(NGGroup.java:235)
    at com.sun.javafx.sg.prism.NGRegion.renderContent(NGRegion.java:577)
    at com.sun.javafx.sg.prism.NGNode.doRender(NGNode.java:2053)
    at com.sun.javafx.sg.prism.NGNode.render(NGNode.java:1945)
    at com.sun.javafx.sg.prism.NGGroup.renderContent(NGGroup.java:235)
    at com.sun.javafx.sg.prism.NGRegion.renderContent(NGRegion.java:577)
    at com.sun.javafx.sg.prism.NGNode.doRender(NGNode.java:2053)
    at com.sun.javafx.sg.prism.NGNode.render(NGNode.java:1945)
    at com.sun.javafx.sg.prism.NGGroup.renderContent(NGGroup.java:235)
    at com.sun.javafx.sg.prism.NGRegion.renderContent(NGRegion.java:577)
    at com.sun.javafx.sg.prism.NGNode.doRender(NGNode.java:2053)
    at com.sun.javafx.sg.prism.NGNode.render(NGNode.java:1945)
    at com.sun.javafx.sg.prism.NGGroup.renderContent(NGGroup.java:235)
    at com.sun.javafx.sg.prism.NGRegion.renderContent(NGRegion.java:577)
    at com.sun.javafx.sg.prism.NGNode.doRender(NGNode.java:2053)
    at com.sun.javafx.sg.prism.NGNode.render(NGNode.java:1945)
    at com.sun.javafx.sg.prism.NGGroup.renderContent(NGGroup.java:235)
    at com.sun.javafx.sg.prism.NGRegion.renderContent(NGRegion.java:577)
    at com.sun.javafx.sg.prism.NGNode.doRender(NGNode.java:2053)
    at com.sun.javafx.sg.prism.NGNode.render(NGNode.java:1945)
    at com.sun.javafx.sg.prism.NGGroup.renderContent(NGGroup.java:235)
    at com.sun.javafx.sg.prism.NGRegion.renderContent(NGRegion.java:577)
    at com.sun.javafx.sg.prism.NGNode.doRender(NGNode.java:2053)
    at com.sun.javafx.sg.prism.NGNode.render(NGNode.java:1945)
    at com.sun.javafx.sg.prism.NGGroup.renderContent(NGGroup.java:235)
    at com.sun.javafx.sg.prism.NGRegion.renderContent(NGRegion.java:577)
    at com.sun.javafx.sg.prism.NGNode.doRender(NGNode.java:2053)
    at com.sun.javafx.sg.prism.NGNode.render(NGNode.java:1945)
    at com.sun.javafx.sg.prism.NGGroup.renderContent(NGGroup.java:235)
    at com.sun.javafx.sg.prism.NGRegion.renderContent(NGRegion.java:577)
    at com.sun.javafx.sg.prism.NGNode.doRender(NGNode.java:2053)
    at com.sun.javafx.sg.prism.NGNode.render(NGNode.java:1945)
    at com.sun.javafx.sg.prism.NGGroup.renderContent(NGGroup.java:235)
    at com.sun.javafx.sg.prism.NGRegion.renderContent(NGRegion.java:577)
    at com.sun.javafx.sg.prism.NGNode.doRender(NGNode.java:2053)
    at com.sun.javafx.sg.prism.NGNode.render(NGNode.java:1945)
    at com.sun.javafx.sg.prism.NGGroup.renderContent(NGGroup.java:235)
    at com.sun.javafx.sg.prism.NGRegion.renderContent(NGRegion.java:577)
    at com.sun.javafx.sg.prism.NGNode.doRender(NGNode.java:2053)
    at com.sun.javafx.sg.prism.NGNode.render(NGNode.java:1945)
    at com.sun.javafx.tk.quantum.ViewPainter.doPaint(ViewPainter.java:477)
    at com.sun.javafx.tk.quantum.ViewPainter.paintImpl(ViewPainter.java:330)
    at com.sun.javafx.tk.quantum.UploadingPainter.run(UploadingPainter.java:134)
    at java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:511)
    at java.util.concurrent.Futuretask.runAndReset(Futuretask.java:308)
    at com.sun.javafx.tk.RenderJob.run(RenderJob.java:58)
    at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1149)
    at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:624)
    at com.sun.javafx.tk.quantum.QuantumRenderer$PipelineRunnable.run(QuantumRenderer.java:125)
    at java.lang.Thread.run(Thread.java:748)
java.lang.IllegalArgumentException: ALPHA color component is out of range
    at com.sun.pisces.PiscesRenderer.checkColorRange(PiscesRenderer.java:113)
    at com.sun.pisces.PiscesRenderer.setColor(PiscesRenderer.java:105)
    at com.sun.prism.sw.SWPaint.setColor(SWPaint.java:76)
    at com.sun.prism.sw.SWPaint.setPaintBeforeDraw(SWPaint.java:118)
    at com.sun.prism.sw.SWPaint.setPaintFromShape(SWPaint.java:86)
    at com.sun.prism.sw.SWGraphics.paintShape(SWGraphics.java:493)
    at com.sun.prism.sw.SWGraphics.drawLine(SWGraphics.java:545)
    at com.sun.javafx.sg.prism.NGCanvas.handleRenderOp(NGCanvas.java:1219)
    at com.sun.javafx.sg.prism.NGCanvas.renderStream(NGCanvas.java:1103)
    at com.sun.javafx.sg.prism.NGCanvas.renderContent(NGCanvas.java:609)
    at com.sun.javafx.sg.prism.NGNode.doRender(NGNode.java:2053)
    at com.sun.javafx.sg.prism.NGNode.render(NGNode.java:1945)
    at com.sun.javafx.sg.prism.NGGroup.renderContent(NGGroup.java:235)
    at com.sun.javafx.sg.prism.NGRegion.renderContent(NGRegion.java:577)
    at com.sun.javafx.sg.prism.NGNode.doRender(NGNode.java:2053)
    at com.sun.javafx.sg.prism.NGNode.render(NGNode.java:1945)
    at com.sun.javafx.sg.prism.NGGroup.renderContent(NGGroup.java:235)
    at com.sun.javafx.sg.prism.NGRegion.renderContent(NGRegion.java:577)
    at com.sun.javafx.sg.prism.NGNode.doRender(NGNode.java:2053)
    at com.sun.javafx.sg.prism.NGNode.render(NGNode.java:1945)
    at com.sun.javafx.sg.prism.NGGroup.renderContent(NGGroup.java:235)
    at com.sun.javafx.sg.prism.NGRegion.renderContent(NGRegion.java:577)
    at com.sun.javafx.sg.prism.NGNode.doRender(NGNode.java:2053)
    at com.sun.javafx.sg.prism.NGNode.render(NGNode.java:1945)
    at com.sun.javafx.sg.prism.NGGroup.renderContent(NGGroup.java:235)
    at com.sun.javafx.sg.prism.NGRegion.renderContent(NGRegion.java:577)
    at com.sun.javafx.sg.prism.NGNode.doRender(NGNode.java:2053)
    at com.sun.javafx.sg.prism.NGNode.render(NGNode.java:1945)
    at com.sun.javafx.sg.prism.NGGroup.renderContent(NGGroup.java:235)
    at com.sun.javafx.sg.prism.NGRegion.renderContent(NGRegion.java:577)
    at com.sun.javafx.sg.prism.NGNode.doRender(NGNode.java:2053)
    at com.sun.javafx.sg.prism.NGNode.render(NGNode.java:1945)
    at com.sun.javafx.sg.prism.NGGroup.renderContent(NGGroup.java:235)
    at com.sun.javafx.sg.prism.NGRegion.renderContent(NGRegion.java:577)
    at com.sun.javafx.sg.prism.NGNode.doRender(NGNode.java:2053)
    at com.sun.javafx.sg.prism.NGNode.render(NGNode.java:1945)
    at com.sun.javafx.sg.prism.NGGroup.renderContent(NGGroup.java:235)
    at com.sun.javafx.sg.prism.NGRegion.renderContent(NGRegion.java:577)
    at com.sun.javafx.sg.prism.NGNode.doRender(NGNode.java:2053)
    at com.sun.javafx.sg.prism.NGNode.render(NGNode.java:1945)
    at com.sun.javafx.sg.prism.NGGroup.renderContent(NGGroup.java:235)
    at com.sun.javafx.sg.prism.NGRegion.renderContent(NGRegion.java:577)
    at com.sun.javafx.sg.prism.NGNode.doRender(NGNode.java:2053)
    at com.sun.javafx.sg.prism.NGNode.render(NGNode.java:1945)
    at com.sun.javafx.sg.prism.NGGroup.renderContent(NGGroup.java:235)
    at com.sun.javafx.sg.prism.NGRegion.renderContent(NGRegion.java:577)
    at com.sun.javafx.sg.prism.NGNode.doRender(NGNode.java:2053)
    at com.sun.javafx.sg.prism.NGNode.render(NGNode.java:1945)
    at com.sun.javafx.sg.prism.NGGroup.renderContent(NGGroup.java:235)
    at com.sun.javafx.sg.prism.NGRegion.renderContent(NGRegion.java:577)
    at com.sun.javafx.sg.prism.NGNode.doRender(NGNode.java:2053)
    at com.sun.javafx.sg.prism.NGNode.render(NGNode.java:1945)
    at com.sun.javafx.sg.prism.NGGroup.renderContent(NGGroup.java:235)
    at com.sun.javafx.sg.prism.NGRegion.renderContent(NGRegion.java:577)
    at com.sun.javafx.sg.prism.NGNode.doRender(NGNode.java:2053)
    at com.sun.javafx.sg.prism.NGNode.render(NGNode.java:1945)
    at com.sun.javafx.tk.quantum.ViewPainter.doPaint(ViewPainter.java:477)
    at com.sun.javafx.tk.quantum.ViewPainter.paintImpl(ViewPainter.java:330)
    at com.sun.javafx.tk.quantum.UploadingPainter.run(UploadingPainter.java:134)
    at java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:511)
    at java.util.concurrent.Futuretask.runAndReset(Futuretask.java:308)
    at com.sun.javafx.tk.RenderJob.run(RenderJob.java:58)
    at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1149)
    at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:624)
    at com.sun.javafx.tk.quantum.QuantumRenderer$PipelineRunnable.run(QuantumRenderer.java:125)
    at java.lang.Thread.run(Thread.java:748)

编辑2：我找到了一种改善graphics2d绘图质量的方法。通过设置graphics2d对象的渲染提示（感谢Hylian Pickachu的建议），正弦曲线看起来更加平滑。它不如画布示例中的正弦曲线那么尖锐，但我认为我现在可以接受结果。

xiejy1 回答：javafx画布绘制与java.awt.graphics2d绘制相比

一种提高Graphics2D质量的方法是使用RenderingHints。 RenderingHints允许您设置渲染质量与渲染性能之间的平衡，这是一个折衷的考虑，因为您说过通过在Canvas上使用Graphics2D确实获得了性能提升。但是，这种方法将使您可以继续使用Graphics2D并避免崩溃。

canvasgraphics2djavajavafx
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