textBounds on multiline text breaks if global textLeading does not match the provided font size

[davepagurek]

Most appropriate sub-area of p5.js?

• Accessibility
• Color
• Core/Environment/Rendering
• Data
• DOM
• Events
• Image
• IO
• Math
• Typography
• Utilities
• WebGL
• Build process
• Unit testing
• Internationalization
• Friendly errors
• Other (specify if possible)

p5.js version

1.9.4

Web browser and version

Firefox, Chrome

Operating system

MacOS

Steps to reproduce this

Steps:

1. Load a font
2. Measure the textBounds() of multiline text, passing in a larger font size than the default (e.g. 50)
3. The resulting box does not cover the text

Snippet:

In this example, I'm setting the font size on a graphic, so the main canvas still has the default text size:

let message
let fnt
let g


function tightBound() {
  const bbox = fnt.textBounds(message.value(), 0, 0,g.textSize());
  g.noFill()
  g.rectMode(CENTER)
  
  g.rect(0,0,bbox.w,bbox.h)
  console.log(message.value())
}

function preload() {
fnt = loadFont("https://fonts.gstatic.com/s/opensans/v40/memSYaGs126MiZpBA-UvWbX2vVnXBbObj2OVZyOOSr4dVJWUgsg-1y4nY1M2xLER.ttf")
}

function setup() {
  
  createCanvas(windowWidth,windowHeight);
  g = createGraphics(width, height)
message = createElement('textarea');
  message.value('test\nanother')
  message.position(20, 20);
  message.size(300, 200);
  g.textAlign(CENTER,CENTER)
}

function draw() {
  g.background(220);
  g.push()
  g.translate(width/2,height/2)
      g.textFont(fnt);
  g.textSize(50)
  g.text(message.value(),0,0)
  tightBound()
  g.pop()
  image(g, 0, 0)
}

Result:

Expected:

Cause

In the implementation of textBounds, it gets the text leading from the main instance's renderer:

p5.js/src/typography/p5.Font.js

Line 209 in 6781c1d

const lineHeight = p._renderer.textLeading();

I'm not sure the best way to fix this; if you're drawing text onto a different renderer like a graphic, there's not a deterministic way to figure out which renderer to use ahead of time. The best option might be to let you pass that value in, which might require a change to the arguments to this function to not have an overwhelmingly long parameter list.

[dhowe]

Thanks @davepagurek -- this is a known-issue discussed in #6967
The fix, which will hopefully be included in v2.0, is to accept textLeading (and all other relevant params) as part of options