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ma_hty

OpenGL About OpenGL ES

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Hi all, I am trying write a 3D graphics program for my mobile phone (O2 xda zinc, window mobile 6). At the very first beginning, I though OpenGL ES is a good platform for me. However, there are no OpenGL ES implementation available in the window mobile 6 (I guess so). Although there are OpenGL ES implementation available from internet, they make me very nervous about the support in the future. Is there any official OpenGL ES implementation which can benefit my program seamlessly if running on a mobile phone have GPU? By the way, it is very strange that I am able to run a Direct3D example on my mobile phone. If there is no reliable organization offering OpenGL ES implementation, Direct3D will be my only way to go... Thanks.

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There probably is a working OpenGL|ES software renderer that will work well with your device. Direct3D is probably running on the built-in software renderer supplied with WM6. ES is very widely supported and hardware acceleration is becoming standard, even on fairly low-end phones. Direct3D mobile has virtually zero support, and is only available on WM5 and WM6.

If you're only concerned about it running on the phone you have now, use whatever is most convenient. But I wouldn't rely on Direct3D mobile if you want your program to run on more than a small selection of current devices, and probably no future devices with the way that D3Dm adoption is going.

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Sorry, not time to look into more detail on this, cause I'm on the way out the door, but I'm fairly sure there's some conformant implementation for windows mobile... Here's a link to companies with conformant implementation.

http://www.khronos.org/members/conformant/

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Original post by jpilon
Sorry, not time to look into more detail on this, cause I'm on the way out the door, but I'm fairly sure there's some conformant implementation for windows mobile... Here's a link to companies with conformant implementation.

http://www.khronos.org/members/conformant/


Thanks for the link. Actually, I have read that before but I'm not sure what to do with the list.

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Original post by Ravyne
There probably is a working OpenGL|ES software renderer that will work well with your device. Direct3D is probably running on the built-in software renderer supplied with WM6. ES is very widely supported and hardware acceleration is becoming standard, even on fairly low-end phones. Direct3D mobile has virtually zero support, and is only available on WM5 and WM6.

If you're only concerned about it running on the phone you have now, use whatever is most convenient. But I wouldn't rely on Direct3D mobile if you want your program to run on more than a small selection of current devices, and probably no future devices with the way that D3Dm adoption is going.


Nice to hear that (OpenGL is more convenient for me).

Okay... I have another question. Let's say, I wrote my program using a software version of OpenGL ES. And one day, I bought a mobile phone with a GoForce series GPU. What should I do to my program to gain the benefit from the GPU?

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Original post by ma_hty
Okay... I have another question. Let's say, I wrote my program using a software version of OpenGL ES. And one day, I bought a mobile phone with a GoForce series GPU. What should I do to my program to gain the benefit from the GPU?


Nothing. Acceleration is used if it is present if not a software implementation of the API is used to emulate a physical device (this is off course much slower and allot more expensive in terms of battery).

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Original post by ma_hty
Hi all,

I am trying write a 3D graphics program for my mobile phone (O2 xda zinc, window mobile 6).

At the very first beginning, I though OpenGL ES is a good platform for me. However, there are no OpenGL ES implementation available in the window mobile 6 (I guess so). Although there are OpenGL ES implementation available from internet, they make me very nervous about the support in the future.

Is there any official OpenGL ES implementation which can benefit my program seamlessly if running on a mobile phone have GPU?

By the way, it is very strange that I am able to run a Direct3D example on my mobile phone. If there is no reliable organization offering OpenGL ES implementation, Direct3D will be my only way to go...

Thanks.


The existence of a OpenGL ES 1.x or 2.x implementation is a question for the mobile/software vendor (the platform provider).

Under windows mobile it is not unusual to use Vincent ( http://www.vincent3d.com/Vincent3D/index.html ). Though according to the latest information I have access to, Vincent is a discontinued project.

Direct3D mobile is as valid offering as any if that is your intended target platform. I am not aware of an accelerated mobile gpu that offers the direct3d mobile API.

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Original post by dannyBlue
Nothing. Acceleration is used if it is present if not a software implementation of the API is used to emulate a physical device (this is off course much slower and allot more expensive in terms of battery).


Hopefully, it is the case if the software implementation knew the physical device.

However, how can I know the software implementation will use the physical device for acceleration if it is available?

And, that's my major concern in the very first beginning.

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Quote:
Original post by dannyBlue
Nothing. Acceleration is used if it is present if not a software implementation of the API is used to emulate a physical device (this is off course much slower and allot more expensive in terms of battery).


Hopefully, it is the case if the software implementation knew the physical device.

However, how can I know the software implementation will use the physical device for acceleration if it is available?

And, that's my major concern in the very first beginning.


This will depend from platform to platform, but in principle the process is abstracted so that the graphic driver can take care of the issue of acceleration "automatically".

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Original post by dannyBlue
Direct3D mobile is as valid offering as any if that is your intended target platform. I am not aware of an accelerated mobile gpu that offers the direct3d mobile API.


There are mobile GPUs that support accelerated Direct3D, many that support ES also support D3Dm, but not all. There are a few devices that do have D3Dm acceleration, such as the Dell Axim PDA, but I'm not aware of any phones.

Like I said above, I can't stress it enough that Direct3D mobile is really not viable beyond a few specific devices. Very few implementations are hardware accelerated, most software implementations aren't even optimized for the specific processor of the device. OpenGL|ES has tremendous momentum and support which is only growing, so its the smart horse to bet on.

Quote:
Original post by ma_hty
Quote:
Original post by dannyBlue
Nothing. Acceleration is used if it is present if not a software implementation of the API is used to emulate a physical device (this is off course much slower and allot more expensive in terms of battery).


Hopefully, it is the case if the software implementation knew the physical device.

However, how can I know the software implementation will use the physical device for acceleration if it is available?

And, that's my major concern in the very first beginning.


It depends, there's a few models that can be followed. If you statically-link to a pure-software implementation, then all the drawing code is internal to your application and it will not be hardware accelerated even if the device does support it. Some implementations might dynamically load the drawing code from a DLL, in which case it's possible to create an alternate DLL which forwards the drawing calls to the hardware GPU. Another possibility is that the code is statically linked against an interface which talks to a driver, and that said driver will be hardware accelerated or software itself.

You'll have to discover for yourself which case applies to your implementation, but in all cases, the code that you write *is* openGL|ES code, and all it should take, at most, to gain hardware acceleration is a recompile against an implementation that supports hardware.

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Original post by Ravyne
... all it should take, at most, to gain hardware acceleration is a recompile against an implementation that supports hardware.


That's a reasonable load of work. Thank you very much. ^^

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