Technical Advisory Committee

I'm forming a technical advisory committee.  We'll meet a few times and discuss the iOS Metal port and rendering architecture in the toolkit.

This post is for developers I'm trying to recruit to the committee.  Let's start with the basics.

What is WhirlyGlobe-Maply?

National Geographic World Atlas (RIP)

WhirlyGlobe-Maply is a real time geospatial display toolkit for iOS and Android.  It's used in a whole bunch of apps, like FlyQ EFB and a few big weather apps like Dark Sky.

Dark Sky

The toolkit's been around since 2011 and it's carved out a crazy little niche in aviation and weather.  It's not a wildly profitable business, but it doesn't lose money either.  How many can say that?

Morecast

Oh, and it's open source.  So that's fun.

WhirlyGlobe-Maply 3.0

The last version I shipped was 2.6 a few weeks.  A huge improvement for data loading on iOS and a nice upgrade to the Android build system.  I.... need to do a post on that.  But no time.

3.0 is the big upgrade.  I'm going to add iOS Metal support, redo the rendering internals and upgrade the Android port with a better shared C++ core and newer versions of OpenGL ES.

Technical Advisory Committee

So here's the deal.  I'm adding a new renderer for Metal and replumbing the internals to match.  I'd really love to discuss it with a few experts along the way.

This is an open source project so, you know, not a ton of resources.  Here's what I'm offering:

• Free lunch in a pleasant conference room at my coworking space in San Francisco
• An invitation to pontificate on real time rendering without having to do any work
• A cool entry on your resume

You do not need to know anything about geospatial or weather or aviation.  I got that covered.  Here's what I need from you:

• Work in San Francisco or nearby.  No budget for travel, sorry.
• Know something about real time rendering, iOS Metal or Android OpenGL 3.x
• Willingness to chat about real time rendering

It's your real time rendering chops I'm interested in.  So game developers most welcome!

Contact me at sjg@mousebirdconsulting.com and we'll see if you're a good fit.

Metal & WhirlyGlobe-Maply

I'm sure I've got users who aren't glued to the WWDC announcements this week.  But then they're not sending me email.  So let's talk Metal.

Courtesy wikipedia, CC by 3.0

Metal is Apple's replacement for OpenGL ES, just to oversimplify it.  Am I going to support it?  I'm thinking about it.

Problems With OpenGL ES

If you're not neck deep in OpenGL ES, you might not really get what this is about.  I am.  It's what you people pay me to do.  Those of you that are paying me, anyway.

Ever written any OpenGL ES code?  It's pretty annoying.  You're setting things up all over the damn place and then carefully tearing them down again.  If you get it right, it's fine.  If you don't... well OpenGL has a million ways to display nothing and you just found another one.

Will Metal fix that?  Eh, probably not, but it will help with the set up and tear down problem.

OpenGL ES also has several mechanisms for moving memory around.  But it's memory... can't we just... move it around?  We can and there are extensions to make that easier.

In Support of Metal

Extension abuse is sort of the problem.  A lot of the fast paths through OpenGL are extensions and they're kinda goofy.  Even worse, OpenGL ES is by no means easy to use and it still has some cruft from the 1.0 days.  Moreover, it's diverged from the way hardware works.  Again.

If you look at the Metal docs, you can see the outline of how experienced developers use OpenGL ES, 2.0 or later.  It just all makes sense... if you do this stuff for a living.  It's about talking to the hardware in a way it expects compatible with how we actually work.

So I'm going to support it?  Maybe.

In Not So Much Support of Metal

This is about as far from a standard as you can get and no one is going to stop supporting OpenGL ES.  Because Android.

I've spent a while porting to Android.  Quite a while.  The OpenGL ES support there is.... fine.  I've had to turn off some of my favorite extensions, but it's okay, I was expecting that.  <sigh>  But this code isn't going to go away, I'm still going to support OpenGL ES indefinitely.  So will the game engines.

Metal is obviously something of an experiment.  Apple doesn't know how this is going to work out and neither do I.  OpenGL, for its flaws, has survived its imminent demise before.  I wouldn't bet on Apple.

So Will I or Won't I?

For WhirlyGlobe-Maply rendering isn't the hard part.  It's data management.  Getting all those vertices and texels into the right places is the tricky bit.  That doesn't change with Metal.  It's still the same logic, threading, and debugging.

So sure, I'd be happy to replace OpenGL ES with Metal.  And then I might turn around and port to DirectX, assuming Microsoft can ever get any mobile market share.

Here's one thing I will be doing.  I'll be discussing it with my performance minded clients and putting together estimates.  I think the chance is quite high.