The Sonic Decompilations Megathread.

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Ian Micheal
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Re: The Sonic Decompilations Megathread.

Post by Ian Micheal »

Code: Select all

8:31 PM] ian micheal:
KOS Vram Usage
Post by PH3NOM » Thu Oct 06, 2016 2:54 pm

Whats up guys?

As my game has been increasing in size and complexity, I have been finding more ways to squeeze out performance of the system.

Recently, I realized that I had gotten to the point where I was sending more vertices than my pvr vertex buffer could support, and needed to increase the Vertex Buffer Size on PVR initialization.

Problem is, once I did that, I ran out of texture memory, and was afraid I would have to decrease textures quality to get everything to fit.

But first, I started digging around in KOS to look at how the Vertex Buffers were allocated, and I noticed a few questionable comments:
on pvr_buffers.c:
Line 234:
CODE: SELECT ALL

        outaddr += buf->opb_size;   /* Do we _really_ need this twice? */
So I simple commented that line out

and Line 245:
CODE: SELECT ALL

        /* XXX What the heck is this 0x50580 magic value?? All I
           remember about it is that removing it makes it fail. */
        buf->opb_size = 0x50580 + polybuf;
I made some testing an arrived at
CODE: SELECT ALL

        buf->opb_size = 0x14160 + polybuf;
On a default pvr_init_defaults, the original code gives us 4,626,688 bytes of Texture Memory Available.
With my new changes to pvr_buffers.c, pvr_init_defaults gives us 5,855,232 bytes of Texture Memory Available.

With this change, I was able to increase my Vertex Buffer size, without having to sacrifice Texture Quality.

Just posting this so see if I am missing something here, I have ran many tests on real hardware, and I can see no adverse effects, only more VRAM available.
[8:33 PM] ian micheal: It seems like i learn a lot from  PH3NOM  these days but this was amazing to me since ti works and you get  With His new changes to pvr_buffers.c, pvr_init_defaults gives us 5,855,232 bytes of Texture Memory Available. so kos your using On a default pvr_init_defaults, the original code gives us 4,626,688 bytes of Texture Memory Available.... Not seen a problem with this change only more vram

dcsteve
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Re: The Sonic Decompilations Megathread.

Post by dcsteve »

Absolutely amazing Ian. Your coding skills are on a whole another level compared to 10 years ago!!

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Ian Micheal
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Re: The Sonic Decompilations Megathread.

Post by Ian Micheal »

dcsteve wrote:Absolutely amazing Ian. Your coding skills are on a whole another level compared to 10 years ago!!
You would hope so steve lol I got it built I'm not sure it work anyways it's untested but i got it to build anyways..

Src is there since it builds it should be easy for others to work on..


I would rather the SDL1.2 build and optimize that because i have that and opengl working very well..

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Ian Micheal
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Re: The Sonic Decompilations Megathread.

Post by Ian Micheal »

well it does try to run but this
--
KallistiOS Git revision v2.0.0-301-ga449e93-dirty:
Thu Jan 21 00:39:45 EST 2021
dogbox2@dogbox2-PC:/opt/toolchains/dc/kos
RetroVM Startup
Requested sbrk_base 0x8d02f000, was 0x8cf2f000, diff 1048576
kernel panic: out of memory; about to run over kernel stack
first thing straight away lack of ram system ram so 1 mb to less to start

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Anthony817
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Re: The Sonic Decompilations Megathread.

Post by Anthony817 »

Is that the version you were trying to get working with SDL 1.2 or the Sappharad source version that is running out of memory?
Image

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Ian Micheal
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Re: The Sonic Decompilations Megathread.

Post by Ian Micheal »

Anthony817 wrote:Is that the version you were trying to get working with SDL 1.2 or the Sappharad source version that is running out of memory?
Sappharad source version dc pre release src

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Anthony817
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Re: The Sonic Decompilations Megathread.

Post by Anthony817 »

Ah ok figured so. Well keep us updated if you have some breakthroughs.
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