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

[Myles C. Maxfield]

This is quite interesting, but I have a bunch of questions regarding this.

What makes the 2D drawing code WebKit-specific? Is it possible to package up the rendering code into a self-contained standalone library?

Regarding text, do you have a strategy for instancing geometry or using a glyph atlas? Did you implement the Loop Blinn path algorithm?

Did you experiment with attempting to re-order independent drawing commands to achieve high GPU occupancy?

Are you measuring power use in addition to time-based performance?

It sounds like OpenGL is doing the drawing itself; I would imagine there are many many draw calls per webpage. Does the OpenGL driver introduce significant overhead?

Are you thinking of publishing your findings? I would be very interested to read about design decisions you encountered along the way.

Thanks,
Myles

> On Nov 13, 2014, at 12:40 AM, Benjamin Poulain <benjamin at webkit.org> wrote:
> 
> How does TyGL perform compared to the other rasterizers?
> 
> What benchmarks do you use to guide the performance work?
> 
>> On 11/12/14, 11:12 PM, Zoltan Herczeg wrote:
>> 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.
>> 
>> 
>> _______________________________________________
>> webkit-dev mailing list
>> webkit-dev at lists.webkit.org
>> https://lists.webkit.org/mailman/listinfo/webkit-dev
> 
> _______________________________________________
> webkit-dev mailing list
> webkit-dev at lists.webkit.org
> https://lists.webkit.org/mailman/listinfo/webkit-dev