How can I paint an image from BufferStrategy to Png file?

Question

I've created a Java program that generates snowflakes and I'd like to save the image created as a .png file once the program finishes drawing.

I've searched on Internet, but I've found only programs using BufferedImage, while I use a BufferStrategy, so I don't know exactly where to start.

The draw method in my program uses a BufferStrategy to create the Graphics component. For example, to draw a simple line the method is:

bs = display.getCanvas().getBufferStrategy();
if (bs == null) {
    display.getCanvas().createBufferStrategy(3);
    return;
}

g = bs.getDrawGraphics();
g.clearRect(0, 0, width, height);
g.setColor(Color.BLACK);
g.drawLine(0, 0, 50, 50);

What I would like is to get an exact copy of what has been drawn on the screen by the program to be saved as a .png image. Hope you can help me.

All you need to do is pass the Graphics object (g) that you created into paint/paintComponent/paintAll from the top level down — ControlAltDel, Jan 29 '19 at 15:29
If you look here at how I did this back in the day, all you need to do is send your Graphics object to paint: https://sourceforge.net/p/tus/code/HEAD/tree/tjacobs/print/StandardPrint.java — ControlAltDel, Jan 29 '19 at 15:33
Instead of painting to the Graphics context of the BufferedStrategy, paint to Graphics context of the image — MadProgrammer, Jan 29 '19 at 18:41

score 0 · Answer 1 · answered Jan 29 '19 at 15:25

0

Why not take a screenshot and then past it onto MS paint or some other(and better) image editing software like Photoshop or fire alpaca? That should solve your problem.

answered Jan 29 '19 at 15:25

MadProgrammer · Answer 2 · 2019-01-29T18:55:19.487

The common denominator between BufferedStrategy and BufferedImage is Graphics, so you want to write a paint routine so that you can simply pass a reference of Graphics to it

public void render(Graphics g) {
    g.clearRect(0, 0, width, height);
    g.setColor(Color.BLACK);
    g.drawLine(0, 0, 50, 50);
}

Then you can pass what ever context you want.

BufferedImage img = new BufferedImage(width, height, BufferedImage.TYPE_RGB);
Graphics2D g2d = img.createGraphics();
render(g2d);
g2d.dispose();

Then you can use ImageIO.write to write the image to disk. See Writing/Saving an Image for more details

How can I paint an image from BufferStrategy to Png file?

2 Answers2