vello_gpu

Vello GPU

GPU renderer with CPU-side preprocessing

A GPU renderer for 2D vector graphics with CPU-side preprocessing.

Vello GPU uses the Sparse Strips architecture to divide work between CPU preprocessing and GPU rendering:

• The CPU processes paths, tiles, and schedules sparse strips.
• The GPU rasterizes those strips and performs compositing.
• The compact strip representation limits data transfer between them.

Key Features

• Efficient path rendering with CPU-side processing
• GPU-accelerated compositing and blending
• Support for both windowed and headless rendering

Feature Flags

• wgpu (enabled by default): Enables the GPU rendering backend via wgpu and includes the required Vello GPU shaders.
• wgpu_default (enabled by default): Enables wgpu with its default hardware backends (such as Vulkan, Metal, and DX12).
• text (enabled by default): Enables glyph rendering (Scene::glyph_run).
• webgl: Enables the WebGL rendering backend for browser support, using GLSL shaders for compatibility.

If you need to customize the set of enabled wgpu features, disable this crate's default features then enable its wgpu feature. You can then depend on wgpu directly, setting the specific features you require. Don't forget to also disable wgpu's default features.

Architecture

The renderer is split into several key components:

• Scene: Manages the render context and path processing on the CPU
• Renderer or WebGlRenderer: Handles GPU resource management and executes draw operations

See the individual module documentation for more details on usage and implementation.

Current state

Vello GPU is a solid GPU-accelerated 2D renderer with broad, reliable feature support. Although it does not match the compute-centric vello renderer's raw performance on dynamic and vector-heavy workloads, it provides excellent performance on workloads that benefit from GPU acceleration, such as images, gradients, and filters. Overall, we still consider it to be slightly less mature than its CPU-only counterpart Vello CPU.

Vello GPU remains under active development. Known limitations include:

• The following features are not yet supported and will panic: Mask layers, complex filter graphs as well as certain blend modes for non-isolated blending.
• Parts of the API and its documentation are still suboptimal, for example the lifecycle and ownership of external resources through Resources.
• Some exposed features remain experimental and are not recommended for use, including glyph caching. Experimental APIs are identified in their method documentation.
• Parts of the rendering pipeline are not yet fully optimized, particularly the wgpu backend, but also other aspects.
• Some failures panic instead of being reported through a user-facing error.

With that said, we are continuously improving Vello GPU and will address these and other limitations in future releases.

Package rename

This package was previously named vello_hybrid. New dependencies and Rust imports should use vello_gpu; no compatibility re-export package is provided in this repository. Existing crates.io releases under vello_hybrid remain available, and publication under the new name may lag behind the repository rename.

Minimum supported Rust Version (MSRV)

This version of Vello GPU has been verified to compile with Rust 1.89 and later.

Future versions of Vello GPU might increase the Rust version requirement. It will not be treated as a breaking change and as such can even happen with small patch releases.

Click here if compiling fails.

As time has passed, some of Vello GPU's dependencies could have released versions with a higher Rust requirement. If you encounter a compilation issue due to a dependency and don't want to upgrade your Rust toolchain, then you could downgrade the dependency.

# Use the problematic dependency's name and version
cargo update -p package_name --precise 0.1.1

Community

Discussion of Vello GPU development happens in the Linebender Zulip, specifically the #vello channel. All public content can be read without logging in.

Contributions are welcome by pull request. The Rust code of conduct applies.

License

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.