TransGaming Transmission: A Closer Look Inside the EVE Online Mac Client

[CCP]

TransGaming Transmission: A Closer Look Inside the EVE Online Mac Client
12 October 2010, 3:05 pm

o/ Capsuleers!

I'm Gavriel State, Founder and Chief Technology Officer at TransGaming,  guest-blogging for CCP to tell you a bit more about the process that we  use to enable EVE on the Mac, and to outline some of the challenges we  face and overcome every day, to bring you the best EVE Mac experience we  can.

As most of you know, EVE on the Mac runs with the support of  TransGaming's Cider technology. Cider provides the Win32 and DirectX  APIs that the game is built with, which allows EVE to be easily released  on both Windows and MacOS X simultaneously. While this is simple to  say, it belies both the enormous complexity of the technology itself as  well as the close cooperation between CCP and TransGaming that makes the  process work.

Typically, when we at TransGaming begin to look at a game, it goes  through three major phases: Evaluation, Production, and Maintenance:

Evaluation

At the evaluation stage, we get our first look at a game, and start to  analyze it for compatibility with Cider and MacOS X. This analysis  usually takes the form of actually getting the game running in a  prototype state, looking at the graphics calls the game is making, doing  performance testing, etc.

Production

Once an evaluation is complete, TransGaming's Production process begins.  The Production team creates a build environment for wrapping a title,  so that Quality Assurance teams at both TransGaming as well as the  game's developer can begin getting game builds to start identifying  problems that must be fixed. The Production team also handles issues  that are outside the scope of the Cider portability engine, such as  installers, patchers, and integration tasks that are specific to a  particular game.

When an issue is found by one of the QA teams it is then tested to  determine whether it is a general game problem, or something that is  somehow specific to the Mac version. This is critical, because bugs that  are on both platforms can only be solved by the game developer  themselves. It's also a difficult job, especially with bugs that only  happen sometimes. As you might imagine, having a series of concrete  steps that can reliably reproduce a bug makes it much easier to solve.

When an issue has been identified that is specific to the Mac,  TransGaming's R&D team becomes responsible for tracking things down  and fixing the problem. This is no easy task, and requires developers  who have broad knowledge of Windows and MacOS, DirectX and OpenGL, and  who really really enjoy debugging complex problems - if you think that  describes you, please let us know! 8-). Every change that the R&D  team does to the core code for Cider is rigorously examined with a  two-level code review process, one review by peers on the team, and  another by a lead developer who is intimately familiar with the code in  question.

In some cases, the problem turns out to be not within Cider, but with  code at the Operating System or driver layer. At that point, we file bug  reports with Apple's 'Radar' system, and try to provide as much  information as possible to them so that they can reproduce a bug. To  help with this process, we often use an internal tool which we call  'Snap', which records all D3D graphics commands used within a frame of a  game into a file that can be played back later, separately from the  game itself. This is especially useful for us when complicated steps are  required to get to a point in the game where the problem occurs, so  that the driver developers don't have to actually play things through to  reproduce a bug!

We communicate with Apple, NVidia, and AMD about radar bugs affecting  Cider based games on a regular basis. Once they understand what's  happening, they will sometimes provide feedback letting us know how we  can avoid an issue, pending a proper fix in an upcoming OS release.  Sometimes, the workaround for a bug is not something that is appropriate  in the general case, but instead makes sense only for that particular  game. When that happens, we create game-specific code changes that we  maintain separately for the life of the game.

Occasionally, we come across functionality that a game requires that is  not available in the OpenGL APIs used by MacOS X. To alleviate this  problem, TransGaming is heavily involved in Khronos, the organization  that defines the OpenGL standard, where we work alongside companies such  as Apple, Intel, NVidia, ATI, and Blizzard to extend the standard with  new functionality. We're very proud of our efforts within Khronos, where  half a dozen significant updates to the OpenGL specification have been  made since we joined in early 2008. Many of the features in the updated  GL standard are already available in MacOS 10.6, and more appear with  each OS update from Apple. The presence or absence of a given OpenGL  feature are often what drives the minimum OS requirements for a given  game.

Maintenance & Branching

Once a game is ready to be shipped, it enters a lock-down phase, where  the Cider engine code is branched so that changes being made for other  games being worked on simultaneously don't affect it. From this stage  forward, only changes specifically targeted for that particular game are  made, and a third level of code review is put in place for any such  changes.

After a game ships, if problems are found by users, developers will  often want to issue patches to the game. TransGaming's Production team  provides developers with the tools required to create and deploy these  patches. If changes are needed on the Cider side for this process, they  still only come from the locked-down code branch.

EVE Online and Rebasing

Unlike most games, even most Massive Multiplayer Games, EVE Online has a  tradition of continuous technology updates. Over the past 4 years that  we've worked with CCP, their team has made dozens of significant changes  such as the Trinity graphics update, switching compiler versions,  stackless IO, planetery interaction, and much more. These "scale up"  updates are significant in scope and they can't be handled in a normal  maintenance patch for Cider.

Instead, every time there has been a major technological update to EVE,  the game has essentially gone through TransGaming's entire cycle above,  using the very latest and greatest version of the Cider engine available  at the time. We call this process 'rebasing', and we try to keep the  process as smooth and invisible as possible, even though under the hood  major changes have happened.

One such rebasing took place with the release of the Trinity graphics  engine on the Mac. This was very complex work for the TransGaming  R&D team to support, requiring an extensive update to support the  Shader Model 3.0 graphics used by EVE, and the D3DX binary shader effect  format that encodes those effects.

Another rebasing occurred with the support of the in-game browser  component. This was an area where TransGaming's Production team took the  lead in integrating the Mac version of the Chromium/Awesomium with EVE,  allowing the Win32 side of the game to call through directly to the  Cocoa-based Mac code. When you run the in-game browser in EVE on the  Mac, everything that happens on the browser side happens entirely in  Cocoa code, which is why the scroll bars and other UI elements in the  Mac version of the game look properly Mac-like. After this initial  integration, we provided CCP with all the tools required for them to  continue to maintain and update the Mac browser component in the future.

A third, more invisible rebasing took place this past August, including  graphics and other updates that will be necessary for support of  upcoming features of new EVE updates that are still under development.

Beyond these major updates, we continually work with CCP on other issues  that come in through both CCP's testing as well as your bug reports.

That's all for this post. Stay tuned for an upcoming post with more  information about the Mac client, including a deep technical dive into  performance analysis and optimization using Apple's Shark and GL  profiler tools.

 -Gav

 

Source: eveonline.com | devBlog