`fullScreen(P2D, SPAN)` does not span across multiple displays on macOS

Most appropriate sub-area of Processing 4?

Core/Environment/Rendering

Processing version

4.5.2

Operating system

MacOS 15.6.1 (24G90)

Bug description

The reference for fullScreen() states that using SPAN should run the sketch “at the full dimensions across all of the attached screens”.

When running a sketch with fullScreen(P2D, SPAN) on my setup, the sketch only appears on the main display.

Hardware setup: 3 external displays connected through an iVANKY FusionDock Max 1 (Note: this is not using DisplayLink):

• DisplayPort → Dell U2720Q (3840×2160)
• HDMI → Dell U2419H (1920×1080)
• HDMI → Dell U2419H (1920×1080)

Steps to reproduce this

1. Connect multiple displays to a macOS machine.
2. Run the sketch below in Processing 4.5.2 (macOS)
3. Observe whether the rendered output spans continuously across all displays.

snippet

// If more than one screen is attached to the computer, run the 
// code at the full dimensions across all of the attached screens

int x = 0;

void setup() {
  fullScreen(P2D, SPAN);
  background(0);
  noStroke();
  fill(102);
}

void draw() {
  rect(x, height*0.2, 1, height*0.6); 
  x = x + 2;
}

Additional context

This may be related to #1426

Would you like to work on the issue?

No, I’m just reporting the issue

首先，在 macOS 上使用多个显示器运行提供的 Processing sketch，并将其行为与 fullScreen() 参考进行比较。查看相关 issue #1426 以了解背景；当 P2D 与 SPAN 能够在所有已连接的显示器上持续渲染，而不仅仅是在主显示器上渲染时，即视为完成。