README.md

DOM Mapper

Projection mapping in the browser for any DOM element, including p5.js and three.js canvases.

This library applies the matrix3d CSS transform to map any DOM element to a projected surface for projector-based installations.

Transformations will be saved in local storage and re-applied on page load.

import dommapper from '@ericrav/dommapper';

const canvas = document.getElementById('canvas');
dommapper(canvas);

const iframe = document.getElementById('iframe');
dommapper(iframe);

document.addEventListener('keypress', (event) => {
  if (event.key === 'h') {
    dommapper.toggleHandles(); // Show/hide handles when done mapping
  }
});

• Call dommapper on any HTML Element
• Drag the corners to map the element to the projected surface
• Shift-click corners to move multiple at once
• Use arrow keys to fine tune selected corners

Installation

Usage with npm and modules

npm install @ericrav/dommapper

import dommapper from '@ericrav/dommapper';

Usage with a global script tag / p5.js

Add script to your index.html file:

<script src="https://www.unpkg.com/@ericrav/dommapper@latest/dist/global.js"></script>

In your JavaScript file:

function setup() {
  let canvas = createCanvas(400, 400);
  dommapper(canvas.elt);
  // uncomment when finished mapping projection
  // dommapper.hideHandles();
}

p5.js web editor example

Usage

dommapper(element, options);

• element - Must be an HTML element in the document
• options - Optional configuration

Options

Option	Description
key	string - Key used to save/load projection points. If omitted, element id or tag name will be used.
initialPoints	number[] - Array of 8 numbers to specify initial projection points. Defaults to element's bounding rect

Additional APIs

// Show/hide all corner handles
dommapper.toggleHandles();
dommapper.showHandles();
dommapper.hideHandles();