2D rendering library, intended for user interfaces.

Features

• Can draw rectangles with rounded corners, borders, and shadows.

• Can draw text using various rasterization backends (freetype, zeno).

• Can fill/stroke vector paths using triangulation through lyon.

• Supports layers for implementing things such as group transparency or tint

• Everything is pluggable: you can implement your own Renderer, TextShaper, FontDatabase, FontRasterizer, AssetSource, ImageDecoder.

Philosophy

The philosophy of Ohm is to optimize rendering for the most common primitives in modern UI: rounded rectangles with borders, shadows and text. Ohm is not a general purpose vector graphics renderer. It's not intended for rendering high quality SVG images (for that you'd use resvg, which is integrated with Ohm through resvg feature)

The default renderer can draw a textured rectangle with rounded corners, borders and a shadow using a single quad. It can also draw text using the same ubershader, minimizing the number draw calls. The renderer doesn't require any special hardware features, such as compute shaders, so should run anywhere.

External dependencies and cargo features

• Enable fontdb feature for access to system fonts (backed by fontdb).

• Enable freetype feature for the FreeType font renderer

• Enable image feature for decoding raster images (backed by image). This also includes raster images, embedded in fonts (such as emoji). You can also enable specific formats using features, such as image/png, image/jpeg.

• Enable resvg feature for rendering SVG images (backed by resvg).

• Enable rustybuzz feature for text shaping (backed by rustybuzz).

• Enable wgpu feature for the default renderer implementation (backed by wgpu).

• Enable zeno feature for a portable font renderer (backed by zeno).

By default, all features are enabled.

License

This project is licensed under either of

• Apache License, Version 2.0, (LICENSE-APACHE or http://www.apache.org/licenses/LICENSE-2.0)
• MIT license (LICENSE-MIT or http://opensource.org/licenses/MIT)

at your option.

Contribution

Unless you explicitly state otherwise, any contribution intentionally submitted for inclusion in the work by you, as defined in the Apache-2.0 license, shall be dual licensed as above, without any additional terms or conditions.