[webkit-dev] Announcing the TyGL-WebKit port to accelerate 2D web rendering with GPU

[Zoltan Herczeg]

Hi All,

We are proud to announce the TyGL port (link:
http://github.com/szeged/TyGL) on the top of EFL-WebKit. TyGL (pronounced
as tigel) is part of WebKit and provides 2D-accelerated GPU rendering on
embedded systems. The engine is purely GPU based. It has been developed on
and tested against ARM-Mali GPU, but it is designed to work on any GPU
conforming to OpenGL ES 2.0 or higher.

The GPU involvement on future graphics is inevitable considering the pixel
growth rate of displays, but harnessing the GPU power requires a different
approach than CPU-based optimizations. 2D graphics is traditionally
software-based however, and 2D APIs are interfaces to these CPU-based
algorithms. WebKit GraphicsContext API is no different, so the key
challenge of our project was and is producing the expected output in a GPU
friendly way.

Key features:

Batching pipeline:

GPU provides the highest performance when a large number of triangles are
drawn with a single draw command without any OpenGL state changes. The
GraphicsContext API in WebKit provides draw operations for single shapes
however, which can result frequent state changes if implemented naively.
TyGL was designed to group these commands to reduce the number of draw
calls.

Automatic shader generator:

TyGL can generate complex shaders from multiple shader fragments, which
allows efficient batching but it also takes care to make them fit into the
shader cache of the GPU.

Trapezoid based path rendering:

TyGL uses trapezoid-based tesselation of shapes and the GPU renders them
with high anti-aliasing quality. We are continuously improving this part
of the engine and look forward to make use of new GPU capabilities (like
Pixel Local Storage) to squeeze more performance out of it.

No software fallback:

The whole engine is optimized for GPU without legacy software fallback.
Hence we don't need to sacrifice optimizations for compatibility. There
are enough software based 2D libraries which can be used when GPU is not
available.

TyGL is already capable of rendering many web-sites correctly, but some
features have not been implemented yet. We continue this work and we are
open to contributions from the community. Contact to us if you want more
information about the project.

Regards,
U-Szeged's web browser team.