vtf-js

A javascript IO library for the Valve Texture Format.

Overview

vtf-js is a canvas-independent library for reading and authoring Vtfs. The library supports encoding and decoding VTF versions 7.1 - 7.6, including Strata-format compressed Vtfs. Mipmap generation is automated by default, however interfaces for manually specifying image data for each mipmap are also available (see VDataCollection).

The following formats are supported by default.

• RGBA8888
• BGRA8888
• BGRX8888
• ABGR8888
• ARGB8888
• RGB888
• BGR888
• RGB565
• BGR565
• IA88
• UV88
• A8
• I8
• P8 ¹
• DXT1
• DXT3
• DXT5
• R32F
• RGB323232F
• RGBA16161616
• RGBA32323232F

Examples

Create from image data

import { Vtf, VFormats, VFilters, VFrameCollection } from 'vtf-js';

// ...

const frames = new VFrameCollection([image], { mipmaps: 3, filter: VFilters.NICE });
const vtf = new Vtf(frames, { version: 4, format: VFormats.DXT5 });
const out = vtf.encode();

Read image into an object

import { Vtf } from 'vtf-js';

// ...

const vtf = Vtf.decode(inbuffer);
const slice = vtf.data.getImage(
	0,  // Mipmap
	0,  // Frame
	0,  // Face
	0   // Slice
);

// The image's data may be a uint8, uint16, or float32 array depending on the format.
// The convert method normalizes the image into the desired format.
const data = slice.convert(Uint8Array);

Re-encode an existing image

import { Vtf, VFormats } from 'vtf-js';

// ...

const vtf = Vtf.decode(inbuffer);
vtf.format = VFormats.RGB565;
vtf.version = 6;
vtf.compression = 4;
const out = vtf.encode();

Footnotes

1. As the Vtf format does not specify a singular method of defining palettes in the file, vtf-js interprets P8 images as a single-channel greyscale image. ↩