Status of double precision

[Shaggy]

Hello,

new info about the doubles?

[Julio Jerez]

No I have not forgotten , I still need one last weekend to complete the vehicle, and next week I will do the double. Sorry about that, I underestimate the time that was going to take me to get the newton vehicle for 3.14
but do no worry I will do the double next.

[misho]

I went away on a vacation hoping to get back to work with double precision. Glad to see it will be implemented soon!

[misho]

Hi Julio - any heads up on the double precision?

Thanks,
Misho

[Julio Jerez]

I start doing it, I have a separate build locally, it should be ready some time this week.

I will not do a complete build of all the project I will only build the DLL.
I assume that since you are using double you are also using dlls,
usually people in console world use static libraries.

[misho]

Actually no, I'm linking to statics... but I can build those myself once you have the code fixed, correct?

[Julio Jerez]

I have such a hard time with VS2010. It is by far the must buggy version of Visual studio after VS 2005
Simple thing like creation a new configuration do work correctly, It create the configuration but does not copy any of the settings and this bug happens randomly.

what I am going to do is that I will made the new debug_double and release_double starting with Visual studio 2012 which seems to do it right, otherwise I have add all the options manually in VS 2010.

I had the same problem last night tryin to make a profile configuration, and I finally settled by doing it in 2012. It has been more than 20 years since visual studio and Microsoft still does not get all the EDI functionality to work as expected.

[misho]

No worries - as long as it supports VS2012 Express edition. I will upgrade!

[zak]

But Visual Studio 2015 Community Edition has ALL the functionalities of PRO version and it is free.
Why not upgrade to it and eliminate all other versions or at least 2010?

[Stucuk]

But Visual Studio 2015 Community Edition has ALL the functionalities of PRO version and it is free.
Why not upgrade to it and eliminate all other versions or at least 2010?

I for one have the free 2013 version. I don't see the point in going through the hassle of "upgrading" to 2015 so i can build Newton. The reason that there is more than one version is so people don't have to download a new version of VS when they already have one.

Downloading and Installing VS 2013 took ages (I literally left it alone for a hour or two), so i kinda avoid upgrades even free ones when they will waste a hour or two for features i will never use.

[misho]

I like it when Julio includes projects for all the "latest" VS's, starting with 2008, which I wouldn't mind if it gets dropped in favor of the latest one. But I do understand if it is a hassle to provide all these different projects. My core project is in VS2010 and from what I understand, I can still build Newton with higher versions and link to them with my VS2010 project. VS allows for multiple versions to co-exist...

I am waiting on pins and needles for this. It is basically a go or no-go for my project

[Julio Jerez]

I am doing it for 2010, and from there is eassy to import for all o ether project.
My problem with VS2010 is that is has many missing features.
But I am still using it.

[misho]

Sounds great to me! Thanks!

Misho

[Julio Jerez]

I now checked in the release_double for visual studio 2010
there si a big performance difference between double and floats

I run the box stack demos, that make few 30 x 30 pyramid until is places little over 1000 bodies in the scene. When I set auto sleep off, the release float run some where between 250 and 300 frames per seconds, while release double is dead locked at 100 fps.

I assume this is expected because the SSE2 can only do half the number of operations of the SSE mode, plus it also requires few overhead instructions to implemented the class with two register where the SSE required only one register and almost off functions can be implemented with one intrinsic. In addition the memory bandwise also double.

I would say that a 4 x 1 SSE2 vector class come out to be at best equal to one not using SSE2.
however it is ok to have it for reference.

In the future we can actually make the double troughtput equal to the throughput of SSE if we make the double class using AVX instructions, then the class will be one register and all operations will be just one intrisics like the SSE dgVector.
My guess is that if we do that the performance can come to maybe 50% closer because there is nothing we cando about the memory bandwidth.

anyway the double version is now in for Visual studio 2010

[misho]

Julio,

I finally found the release_double projects, compiled, adjusted my project to work with it (a few conversions to dFloat ) and success!

My orbital spacecraft are now elegantly floating around each other, in an orbit around earth, at an altitude (from centre of the Earth) of 6,671,451.33821 meters , double-precision physics engine courtesy of Newton Dynamics!

Thank you, sir! Onwards to all the rest of the fun features of the simulator!

Cheers,
Misho