Image Manipulation in Three.js

Three.js doesn't provide direct equivalents to HTML Canvas's drawImage and getImageData methods for image manipulation. However, you can still work with images in Three.js while maintaining consistency by using a combination of Three.js utilities and HTML Canvas as an intermediary.

Using ImageUtils

Three.js provides the ImageUtils class with some basic image utilities:

• ImageUtils.getDataURL() - Converts an image to a data URI
• ImageUtils.sRGBToLinear() - Converts sRGB image data to linear color space

However, these methods don't provide the full functionality you're looking for in terms of combining and splitting images.

Recommended Approach

For image manipulation while staying within the Three.js ecosystem:

1. Use HTML Canvas for the actual image manipulation
2. Convert the results to Three.js textures

Here's a pattern you could follow:

JAVASCRIPTCopied
import * as THREE from 'three';

function combineImages(image1, image2, x, y) {
    // Create a canvas for manipulation
    const canvas = document.createElement('canvas');
    const ctx = canvas.getContext('2d');
    
    // Set canvas size to accommodate both images
    canvas.width = Math.max(image1.width, x + image2.width);
    canvas.height = Math.max(image1.height, y + image2.height);
    
    // Draw images
    ctx.drawImage(image1, 0, 0);
    ctx.drawImage(image2, x, y);
    
    // Create a Three.js texture from the canvas
    const texture = new THREE.CanvasTexture(canvas);
    
    // Optional: get data URL if needed
    const dataURL = THREE.ImageUtils.getDataURL(canvas);
    
    return { texture, canvas, dataURL };
}

function splitImage(image, x, y, width, height) {
    // Create a canvas for the cropped section
    const canvas = document.createElement('canvas');
    canvas.width = width;
    canvas.height = height;
    
    const ctx = canvas.getContext('2d');
    ctx.drawImage(image, x, y, width, height, 0, 0, width, height);
    
    // Create a Three.js texture from the canvas
    const texture = new THREE.CanvasTexture(canvas);
    
    return { texture, canvas };
}

This approach lets you:

1. Perform the image manipulation you need
2. Keep your final results as Three.js textures
3. Maintain a consistent workflow within your Three.js application

While this does use HTML Canvas internally, the interface you expose from your module would be Three.js-centric, returning textures that can be directly used in your Three.js materials.