The Vega State Tracker Gets Cleaned, OpenVG 1.1

Chia-I Wu, the developer who previously worked on the EGL state tracker, brought Mesa to Android netbooks, and allowed Nouveau to work on Wayland (and now is doing work for LunarG), has some improvements to the Vega state tracker. Namely he has cleaned up this Gallium3D state tracker for Mesa and additionally has a branch containing OpenVG 1.1 support.

The Vega state tracker implements OpenVG support on the Gallium3D driver architecture but up to this point it's only implemented the Khronos OpenVG 1.0 specification. With thousands of new lines of code added to the cleaned-up Vega, OpenVG 1.1 is now ready. The new features include mask layer support, text support, and a new color transformation stage.

The cleaned-up branch done by Chia-I is named vega-polish and it adds support for states to the Vega renderer that's used for rendering commands to the Gallium3D pipe context. With the added renderer states to this open-source code, the Vega state tracker is refactored to no longer depend upon OpenVG states but the pipe context state manipulation is all handled by the Vega renderer, in other words there's now a clean layer of abstraction. Additionally, "The benefits of the changes are that code that handles OpenVG functions and code that sets pipe_context is no longer fixed. Since the renderer is an opaque object, its implementation can be changed: Use a different pipe_context function for an OpenVG function or the frequency of pipe state changes may be minimized."

For those not familiar with OpenVG, here's the description from Khronos: "OpenVG is a royalty-free, cross-platform API that provides a low-level hardware acceleration interface for vector graphics libraries such as Flash and SVG. OpenVG is targeted primarily at handheld devices that require portable acceleration of high-quality vector graphics for compelling user interfaces and text on small screen devices - while enabling hardware acceleration to provide fluidly interactive performance at very low power levels." OpenVG 1.1 is the latest version of this specification and it was released in late 2008. At least the open-source graphics community can be caught up to speed on the OpenVG front, but with OpenGL they are years behind.

Additional details on the technical changes and where these two Mesa branches with the revised Vega state tracker can be found are available in this mailing list message.