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Mac: Porting P:O To Intel GMA 950?
myownlittlworld Offline
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Mac: Porting P:O To Intel GMA 950?

So, I bought the Humble Indie Bundle for my fiancee so she could enjoy the wonders of Penumbra: Overture. She's a fan of horror games. They make me jump, but I dig. I was terribly disappointed to find that, because she owns a mid-2007 MacBook, P:O won't run (she'll be playing it on my computer for now).

However, with the recent freeing of P:O, I have the opportunity to hack on it for a while and see what'll come of it. So, I was wondering if you'd be able to give any guidance as to what the porting requirements are to allow the game to run on an Intel GMA 950? Yeah, it's a big change, duh, but how big a change and where in the source? Is it an issue of VRAM space alone, or are there other fundamental issues? My ATI Mobility Radeon 9600 (64MB) seems to play the game fairly well, though I haven't put it through it's traces yet, nor have I had the opportunity to check out the source and start hacking. That'll occur this weekend.

Any advice, other than to go for it with a lot of patience and perseverance? I suppose I could suppress all the texture loading to conserve VRAM or something, assuming that's the issue, but I mostly just need to wrench the laptop away from her for a few hours to read through the associated error messages.

Thank you, guys, so much for doing this. You're really amazing and I hope something wonderful comes from your efforts.

05-15-2010, 04:25 AM
Urkle Offline
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RE: Mac: Porting P:O To Intel GMA 950?

I believe the issue had more to do with the shader capabilities of the card ( or lack of ) than anything else. The sad thing is, the actual card is from 2005 I believe so it's a really old chipset that I am completely surprised apple included it in their product lines. Thought they learned the lesson and have dropped the intel card from newer computer models.

Anyways. All the shader code is in the engine core under the CGProgram.cpp and it hands things off to the nvidia CG library. So I'd start researching with the CG library first for 950gma support.

Developing away on one of
Multiple Macs running 10.6, 10.7, 10.8, and 10.9.
Linux, 8-core AMD, 8GB RAM, Fedora 18, nVidia 450 1GB
05-15-2010, 05:27 AM
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Thomas Offline
Frictional Games

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RE: Mac: Porting P:O To Intel GMA 950?

The problem with these cards is not only their capabilities but that the card lies about them. So if you check for vertex shader support and so on, the card will say it handles it, but in reality it does not, so it is hard to choose a correct render path.

HPL1 relies a lot on having vertex shaders (works fine without fragment shaders) and you would have to come up with some alternative if you want it to work on these cards. I have given it some time, but did not manage to add support. Should not be impossible, but you would need to have some sort of trix up your sleeve (or at least just know something I did not Tongue Which I admit is not that hard Smile)
05-15-2010, 09:02 AM

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