with second applet, strange errors about createGraphics

prismspecs

PGraphics canvas;

void setup() {
  size(400, 400, P3D);
  canvas = createGraphics(400, 400, P3D);

  String[] args = {"YourSketchNameHere"};
  SecondApplet sa = new SecondApplet();
  PApplet.runSketch(args, sa);
}

void draw() {

  canvas.beginDraw();
  canvas.background(127);
  canvas.lights();
  canvas.translate(width/2, height/2);
  canvas.rotateX(frameCount * 0.01);
  canvas.rotateY(frameCount * 0.01);  
  canvas.box(150);
  canvas.endDraw();
  image(canvas, 0, 0);
}     

public class SecondApplet extends PApplet {

  public void settings() {
    size(200, 100,P3D);
  }
  public void draw() {
    background(255);
    fill(0);
    ellipse(100, 50, 10, 10);
  }
}

With that code I get "createGraphics() requires size to use P3D or P2D" (paraphrasing)

Or if I try to create an instance of a Syphon window, for example, I get null pointer.

What's the deal? My goal is to create a 2-window app with Syphon output from one window and a P5 control setup on the other.

kfrajer

Place line 4 in its own settings function.

Kf

neilcsmith_net

Personally I'd be wary of using P2D/P3D in both PApplets - there's some dodgy resource clean up code in the OpenGL renderer that might cause crashes in some circumstances doing this.

GoToLoop

Personally I'd be wary of using P2D/P3D in both PApplets...

https://Forum.Processing.org/two/discussion/26815/arraylist-concurrentmodificationexception#Item_2

GoToLoop

If Processing 3's pre-processor spots any method called settings() anywhere inside a ".pde" file, it won't create its own settings() anymore behind the scenes. :-SS

It means that your 1st size(400, 400, P3D); is gonna stay inside setup() rather than being automatically moved into settings(): :-S

https://Processing.org/reference/settings_.html

neilcsmith_net

@GoToLoop - yes, there's definitely that as well! :-) What I'm thinking of is that they took my suggestion of extending WeakReference in PGraphicsOpenGL to handle resource cleanup, but ignored my complaint that there's one static list. It means that with two PApplets using OpenGL you can have one cleaning up the resources of the other - this may or may not be a problem on any particular system, driver, etc.