Pathfinder

Pathfinder is a fast, practical GPU-based rasterizer for OpenType fonts using OpenGL 4.3. It features:

• Very low setup time. Glyph outlines can go from the .otf file to the GPU in a form ready for rasterization in less than a microsecond. There is no expensive tessellation or preprocessing step.

• High quality antialiasing. Unlike techniques that rely on multisample antialiasing, Pathfinder computes exact fractional trapezoidal area coverage on a per-pixel basis.

• Fast rendering, even at small pixel sizes. On typical systems, Pathfinder should easily exceed the performance of the best CPU rasterizers.

• Low memory consumption. The only memory overhead over the glyph and outline storage itself is that of a coverage buffer which typically consumes somewhere between 4MB-16MB and can be discarded under memory pressure. Outlines are stored on-GPU in a compressed format and usually take up only a few dozen kilobytes.

• Portability to most GPUs manufactured in the last few years, including integrated GPUs.

Authors

The primary author is Patrick Walton (@pcwalton), with contributions from the Servo development community.

The code is owned by the Mozilla Foundation.

License

Licensed under the same terms as Rust itself. See LICENSE-APACHE and LICENSE-MIT.