Pre-render Canvas content

Question

Hello,
I have to visualize lot of data and I have to do it fast and without GUI freezing.
* This code is running in non GUI Thread
final WritableImage img = new WritableImage(500, 900);
Canvas tmpCanvas = new Canvas(500, 900);
// Draw something to Canvas
* Now I need render content of Canvas and put pixel to WritableImage.
Platform.runLater(new Runnable() {
                @Override
                public void run() {
                    canvas.getGraphicsContext2D().drawImage(img, 40, 60);  // put pre-rendered result to GUI Thread.
});Is there even some way how to do it?
Thx for answer. :-)

Answer 1

To my knowledge it is currently not possible to render anything in JavaFX outside of the rendering thread. Even the canvas first builds up a rendering list when you issue rendering commands which is then executed on the rendering thread. This has the effect that any long-time rendering will at some time block the GUI because it cannot be done in a separate thread.
By using a WritableImage you could of course implement your own software rendering but that is probably not what you want :-)