PGraphics saves fully transparent instead of red (P2D)

[processing-bot]

Created by: clankill3r

Processing 4.2, OSX 10.15.7

void setup() {
  size(600, 600, P2D);
  PGraphics pg = createGraphics(64, 64, P2D);
  pg.beginDraw();
  pg.background(255, 0, 0);
  pg.endDraw();

  image(pg, 0, 0);

  pg.save("bug.png");
}

It should save a red image, but it's fully transparent.

[processing-bot]

Created by: SableRaf

Hi @clankill3r and thanks for reporting this issue.

My best guess for what's happening is that Processing's graphics pipeline might not have finished rendering pg before the save() command is executed.

Here is a possible workaround that works as expected:

PGraphics pg;

void setup() {
  size(600, 600, P2D);
  pg = createGraphics(64, 64, P2D);
}

void draw(){
  pg.beginDraw();
  pg.background(255, 0, 0);
  pg.endDraw();
  pg.save("bug.png");
  image(pg, 0, 0);
  
  if(frameCount>1) {
    noLoop();
  }
}

This alternative approach moves the rendering to draw() and ensures the rendering is complete before saving.

Hope this helps! Please let us know if you encounter further issues.