javafx canvas draw 与 java.awt.graphics2d draw 的比较

Question

我想显示一个相对较长的图表。我曾经使用过 javafx Canvas ，但有时会出现缓冲区溢出异常，因为绘制了很多值。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 的优点是性能提高了，我没有异常(exception)。缺点是图表的质量。使用 graphics2d，图表看起来不像 javafx 中 Canvas 中的图表那么平滑。

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 Canvas 示例？
或者有没有我没有想到的不同方法可以解决我的问题？

Canvas 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();
    }
}

新的 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:我找到了一种提高 graphics2d 绘图质量的方法。通过为 graphics2d 对象设置渲染提示(感谢 Hylian Pickachu 的建议)，正弦曲线看起来更平滑。它不像 Canvas 示例中的正弦曲线那么尖锐，但我想我现在可以接受结果了。

Answer 1

提高 Graphics2D 质量的一种方法是使用 RenderingHints . RenderingHints 允许您设置渲染质量与渲染性能之间的平衡，这是一个需要考虑的权衡，正如您所说，您确实喜欢使用 Graphics2D 而不是 Canvas 带来的性能提升。但是，这种方法将允许您继续使用 Graphics2D 并避免崩溃。