Very large canvases in JavaFX2

问题:

My application has a very large Canvas contained by a ScrollPane.

At about 10 million pixels JavaFX starts throwing these null pointer exceptions during canvas operations:

at com.sun.javafx.sg.prism.NGCanvas$RenderBuf.validate(Unknown Source)
at com.sun.javafx.sg.prism.NGCanvas.initCanvas(Unknown Source)
at com.sun.javafx.sg.prism.NGCanvas.renderContent(Unknown Source)
at com.sun.javafx.sg.prism.NGNode.doRender(Unknown Source)
at com.sun.javafx.sg.prism.NGNode.doRender(Unknown Source)
at com.sun.javafx.sg.BaseNode.render(Unknown Source)
at com.sun.javafx.sg.prism.NGGroup.renderContent(Unknown Source)
at com.sun.javafx.sg.prism.NGRegion.renderContent(Unknown Source)
at com.sun.javafx.sg.prism.NGNode.doRender(Unknown Source)
at com.sun.javafx.sg.prism.NGNode.doRender(Unknown Source)
at com.sun.javafx.sg.BaseNode.render(Unknown Source)
at com.sun.javafx.sg.prism.NGGroup.renderContent(Unknown Source)
at com.sun.javafx.sg.prism.NGRegion.renderContent(Unknown Source)
at com.sun.javafx.sg.prism.NGNode.renderForClip(Unknown Source)
at com.sun.javafx.sg.prism.NGNode.renderRectClip(Unknown Source)
at com.sun.javafx.sg.prism.NGNode.renderClip(Unknown Source)
at com.sun.javafx.sg.prism.NGNode.doRender(Unknown Source)
at com.sun.javafx.sg.prism.NGNode.doRender(Unknown Source)
at com.sun.javafx.sg.BaseNode.render(Unknown Source)
at com.sun.javafx.sg.prism.NGGroup.renderContent(Unknown Source)
at com.sun.javafx.sg.prism.NGRegion.renderContent(Unknown Source)
at com.sun.javafx.sg.prism.NGNode.doRender(Unknown Source)
at com.sun.javafx.sg.prism.NGNode.doRender(Unknown Source)
at com.sun.javafx.sg.BaseNode.render(Unknown Source)
at com.sun.javafx.sg.prism.NGGroup.renderContent(Unknown Source)
at com.sun.javafx.sg.prism.NGNode.doRender(Unknown Source)
at com.sun.javafx.sg.prism.NGNode.doRender(Unknown Source)
at com.sun.javafx.sg.BaseNode.render(Unknown Source)
at com.sun.javafx.sg.prism.NGGroup.renderContent(Unknown Source)
at com.sun.javafx.sg.prism.NGRegion.renderContent(Unknown Source)
at com.sun.javafx.sg.prism.NGNode.doRender(Unknown Source)
at com.sun.javafx.sg.prism.NGNode.doRender(Unknown Source)
at com.sun.javafx.sg.BaseNode.render(Unknown Source)
at com.sun.javafx.tk.quantum.ViewPainter.doPaint(Unknown Source)
at com.sun.javafx.tk.quantum.AbstractPainter.paintImpl(Unknown Source)
at com.sun.javafx.tk.quantum.PresentingPainter.run(Unknown Source)
at java.util.concurrent.Executors$RunnableAdapter.call(Unknown Source)
at java.util.concurrent.FutureTask.runAndReset(Unknown Source)
at com.sun.prism.render.RenderJob.run(Unknown Source)
at java.util.concurrent.ThreadPoolExecutor.runWorker(Unknown Source)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(Unknown Source)
at com.sun.javafx.tk.quantum.QuantumRenderer$PipelineRunnable.run(Unknown Source)
at java.lang.Thread.run(Unknown Source)

I think the solution must be to virtualize the Canvas. I imagine this is conceptually similar to how ListView is implemented.

Please point me to any examples you may know of that are similar to this or any pages that may provide guidance. (Virtual and virtualized don't seem to be helpful keywords for googling this topic)

Thank you

回答1:

We faced the same problem. The explanation why it happens, is here: https://community.oracle.com/thread/3549359

We solved the problem bypassing the video card, using the following JVM parameter:

-Dprism.order=sw

You may want to increase heap memory as well using -Xmx because it will use much more memory.