// specific image size in millimeters at given DPI.

//

// Usually for print the canvas may by much bigger than

// the available preview size, so scale it as well.

​

// Pierre Rossel - 2024-04-16

​

​

// Size of the saved image and its DPI

const mmWidth = 895; // width in millimeters

const mmHeight = 1280; // height in millimeters

const dpi = 150;

​

function setup() {

  // Calculate the canvas size

  const wCanvas = round(((mmWidth / 25.4) * dpi) / pixelDensity());

  const hCanvas = round(((mmHeight / 25.4) * dpi) / pixelDensity());

​

  print(wCanvas, hCanvas);

  // Create the canvas

  createCanvas(wCanvas, hCanvas);

​

  // Reduce size of preview

  // Adjust as needed to fit the canvas in the preview area

  let scalePreview = 0.2;

  let cnv = document.getElementById("defaultCanvas0");

  cnv.style.width = round(width * scalePreview) + "px";

  cnv.style.height = round(height * scalePreview) + "px";

​

  // Button to save image

  createButton("Save image").mousePressed(() => save(

    "Canvas_" + year() + nf(month(), 2) + nf(day(), 2) + 

    "_" + nf(hour(), 2) + nf(minute(), 2) + nf(second(), 2) + ".jpg"

  ));

}

​

function draw() {

  background(220);

  noStroke();

  translate(width / 2, height / 2);

  rotate(millis() / 500);

  ellipse(width / 4, 0, width / 4);

}

​