PImage.resize() not implemented in Processing 4??

[jordirosa-p5]

Description

The resize method for the PImage class is not implemented (yet?).

Expected Behavior

PImage.resize() has always worked, resizing the image to the size provided. Code made using previous versions stops working, the documentation in the processing reference web shows resize() as a usable method, though.

Current Behavior

Attempting to using the resize method on a PImage throws an exception, and looking at the Processing 4 code is easy to see why it's throwing it:

public void resize(int w, int h) { // ignore
throw new RuntimeException("resize() not implemented for this PImage type");
}

Steps to Reproduce

Your Environment

• Processing version: 4.0a3
• Operating System and OS version: macOS Big Sur
• Other information:

Possible Causes / Solutions

Is this method going to be implemented in Processing 4?

[behreajj]

If you want to write one for yourself, it depends on what kind of algorithm you want to use (bicubic, bilinear, nearest neighbor). After reading this Stack Overflow discussion, I wrote this Processing code for my own use.

Like the README says, functions that rely on AWT are being shifted around. PImageAWT, a sub-class of PImage, uses a resize function that relies on AWT.

https://github.com/processing/processing4/blob/cbdf55c96d6aedce4c4a36fec8bcd582caf73a7e/core/src/processing/awt/PImageAWT.java#L121

Whether this version of resize is called depends on which renderer you use and whether you use loadImage or createImage.

PGraphics extend PImage. If a resize algorithm were implemented in PImage, all its sub-classes--various graphics renderers included--would need to be tested to see if the parent resize worked or needed an override. Check this issues section for topics on surface.setResizable and you'll see how the problems compound.

[benfry]

If you're using createImage() or loadImage(), you should never run into this.

Can you share an example that causes this problem?

[behreajj]

void setup() {
  size(256, 256, JAVA2D);
  PImage img = createImage(256, 256, ARGB);
  println(img.getClass());
  img.resize(256, 128);
}

[jordirosa-p5]

In my case, the image I need to resize is one I create by calling g.get().

The visual effect i get from my app to create a nice blurry effect totally depends on the last lines in my draw() function. Here is the most simple version of it:

void setup() {
  fullScreen(P3D);
  frameRate(30);

  background(255,255,255);
  stroke(0);
}

void draw(){
  ellipse(width*0.5, height*0.5, 20, 20);
  
  PImage gBig = g.get();
  gBig.resize(width+2, height+2);
  set(-1, -1, gBig);
}

[benfry]

Perfect, thanks both. resize() should be working in both of those cases; I'll check into what's going on.

[jordirosa-p5]

Thank you!

[benfry]

Fixed for 4.0 alpha 4.

[github-actions]

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