Fast blur in JAVA2D

Processing Coding Questions
1

Hello,

I need some fast blur for a sketch I am making. So far I have only tried filter(), but

  1. it is slow
  2. I need to blur only an area, not the entire image

The blur needs to run smoothly at 60 fps. Is this possible with JAVA2D?

2

Hi @lqdev I assume you already tried the Pimage filter in processing And the frameRate() function?
https://processing.org/reference/PImage_filter_.html
Can you explain your project in more detail please? :slight_smile:

3

Hi,

Have you tried the blur pass from the PostFx library ? It’s pretty fast.

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4

The problem is, that I need the JAVA2D renderer, because it’s the only one that supports clip() properly.

5

Well instead of writing an efficient bur implementation in JAVA2D (which is not really possible), I would recommend you to write a shader which clips the output of your sketch :slight_smile:

But first, tell us a bit more about the clipping problem you experience in P2D?

6

I have already switched to FX2D, which solves my blur problems (and I used a clip()/noClip() support workaround), and improves overall performance a lot.

Anyways, the problem with clip() in P2D and P3D is that transformations don’t apply to the clip. An issue has already been reported on this problem.

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7

The solution for FX2D is very simple! However, it works different than filter(), but for my case it is perfect. Unfortunately this won’t work on other renderers, here’s the code:

void draw() {
  GraphicsContext ctx = ((Canvas) surface.getNative()).getGraphicsContext2D();
  GaussianBlur blur = new GaussianBlur();
  blur.setRadius(10);
  ctx.setEffect(blur);
  // do some drawing, anything drawn from here on will be blured
  // to disable the effect, do:
  ctx.setEffect(null);
}

JavaFX includes multiple more effects, like Glow and DropShadow, be sure to check them out if you want lag-free effects.
Don’t remember which package they’re from, you’ll have to search yourself.

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