Error when using .get() on PImage and PGraphics layers

[jake-welch-design]

Most appropriate sub-area of Processing 4?

Image

Processing version

4.4.7

Operating system

MacOS

Bug description

When using .get() on a PImage or PGraphics layer, only data from the top left quadrant of the layer is retrieved, and it is scaled up. I tested this on an old sketch that used to use a buffer this way and I can confirm that it behaves improperly now.

Steps to reproduce this

1. Display image in a PGraphics Layer

2. (optional) Create PImage buffer of PGraphics layer with .get()

3. Use .get() on either the PGraphics layer or the PImage buffer and display the data. I illustrate this with a pixel grid below.

snippet

PImage img;
PGraphics imgLoad;

void setup() {
  size(1080, 1080);

  imgLoad = createGraphics(width, height);
  img = loadImage("1.jpeg");
  img.resize(width, height);
}


void draw() {
  background(0);

  imgLoad.beginDraw();
  imgLoad.image(img, 0, 0, width, height);
  imgLoad.endDraw();

  PImage imgBuffer = imgLoad.get();

  float tilesX = 150;
  float tilesY = tilesX;
  float tileW = ceil(width / tilesX);
  float tileH = ceil(height / tilesY);

  for (int x = 0; x < tilesX; x++) {
    for (int y = 0; y < tilesY; y++) {

      int px = int(x * tileW);
      int py = int(y * tileH);


      //CHANGE BETWEEN THESE OPTIONS TO SEE THE ISSUE:

      color c = img.get(px, py); // Displays the full image
      //color c = imgLoad.get(px, py); // Displays the top left quadrant of the image
      //color c = imgBuffer.get(px, py); // Displays the top left quadrant of the image


      push();
      stroke(c);
      fill(c);
      rect(px, py, tileW, tileH);
      pop();
    }
  }
}

Additional context

What it should look like:

What it looks like with the bug:

Would you like to work on the issue?

No, I’m just reporting the issue

[SableRaf]

Hi @jake-welch-design.

Since Processing 4.4.3, sketches automatically use pixelDensity(2) on Retina/HiDPI screens. This makes graphics look sharper, but it also means that sketches that use get(), set() may not look the same as they did in earlier versions of Processing.

Try setting pixelDensity(1) in setup() to keep the old behavior everywhere OR adapt your code to the screen’s density by using displayDensity(), so pixel operations scale consistently.

More info: https://github.com/processing/processing4/wiki/Pixel-Density-Changes