p5.js textAscent() Function

The textAscent() function in p5.js is used to find out the ascent of the current font at its current size. The ascent can be defined as the distance of the tallest descender character above the baseline, in pixels.

Syntax:

textAscent()

Parameters: This function has no parameters.

Return Value: It returns a number that denotes the ascent in pixels.

The example below illustrates the textAscent() function in p5.js:

Example 1: This example shows the text ascent using the default font.

let inputElem;
let currfontSize = 24;
let fontBaseline = 150;

function setup() {
  createCanvas(600, 300);

  // Create button to increase font size
  let fontBtn = createButton("Increase Font Size");
  fontBtn.mouseClicked(() => {
    currfontSize += 1;
  });
  fontBtn.position(20, 70);

  // Create input box
  inputElem = createInput("");
  inputElem.position(20, 40);
}

function draw() {
  clear();
  textSize(18);
  text("Write in input to change the text and observe text ascent", 10, 20);
  textSize(currfontSize);

  // This value depends on the font used
  let fontScalar = 0.8;

  // Display text and line if input not empty
  let enteredText = inputElem.value();
  if (enteredText != "") {
    text(enteredText, 20, fontBaseline);

    // Draw the Base line
    stroke("black");
    line(0, fontBaseline, width, fontBaseline);

    // Draw the Ascent Line
    stroke("green");
    ascVal = textAscent() * fontScalar;
    line(0, fontBaseline - ascVal, width, fontBaseline - ascVal);
    noStroke();

    textSize(18);
    text("Text Ascent Value: " + ascVal, 20, 275);
  }
}

Output:

Example 2: This example shows the text ascent using a custom font.

let inputElem;
let currfontSize = 24;
let fontBaseline = 150;
let newFont;

function preload() {
  newFont = loadFont("fonts/Montserrat.otf");
}

function setup() {
  createCanvas(600, 300);

  textFont(newFont);

  // Create button to increase font size
  let fontBtn = createButton("Increase Font Size");
  fontBtn.mouseClicked(() => {
    currfontSize += 1;
  });
  fontBtn.position(20, 70);

  // Create input box
  inputElem = createInput("");
  inputElem.position(20, 40);
}

function draw() {
  clear();
  textSize(18);
  text("Write in input to change the text and observe text ascent", 10, 20);
  textSize(currfontSize);

  // This value depends on the font used
  let fontScalar = 0.8;

  // Display text and line if input not empty
  let enteredText = inputElem.value();
  if (enteredText != "") {
    text(enteredText, 20, fontBaseline);

    // Draw the Base line
    stroke("black");
    line(0, fontBaseline, width, fontBaseline);

    // Draw the Ascent Line
    stroke("green");
    ascVal = textAscent() * fontScalar;
    line(0, fontBaseline - ascVal, width, fontBaseline - ascVal);
    noStroke();

    textSize(18);
    text("Text Ascent Value: " + ascVal, 20, 275);
  }
}

Output:

Online editor: https://editor.p5js.org/

Environment Setup: https://www.geeksforgeeks.org/p5-js-soundfile-object-installation-and-methods/

Reference: https://p5js.org/reference/#/p5/textAscent