Ppsspp: Monster hunter portable 3rd HD graphic glitch

[metaasza]

The ground are blinking like a pixel as in the pictures.
Please help. Thank you very much and sorry for poor English.
ppsspp v0.9.9.1-1282-g102aa8e Android version

[hrydgard]

Are you running on nVidia Shield? It has some weird graphics corruption very similar to this in a few games that I haven't been able to figure out, and suspect is a GPU driver bug.

[metaasza]

I run it on Samsung Galaxy SIII(GT-i9300)

[metaasza]

Is it because that my device was rooted? I've tried many times on settings but it seems that The problem haven't gone yet. Please tell me if there is any chance to solve this;( Thank you very much for your attention.

[metaasza]

@hrydgard Can I do anything if its really GPU driver bug? Thank you very much

[Mullin]

@metaasza : This is a driver bug. I've the same problem on i9300 and i9305, can't reproduce this bug on Nvidia Shield Tablet. Mali have the worst driver ever.

[metaasza]

@Mullin So its cannot be fixed right :(

[hrydgard]

Probably not fixable, yeah :/

[Mullin]

@metaasza : By creating a safe texture cache but this is slower. By luck this is minor graphical bug.

[unknownbrackets]

@Mullin what do you mean by safe texture cache? Do you know any details about this driver bug?

-[Unknown]

[Mullin]

@unknownbrackets : Mali400 have somes issues with ETC texture compression which can cause corruption. Or maybe related to coding texture, this is 16 bits, 24 bits or 32 bits textures ? Mali 400 hate 24 bits textures.

[hrydgard]

We don't use ETC textures at all, as PSP games don't use them. We only use the following texture formats: ARGB4444, ARGB565, ARGB1555 and ARGB8888 (possibly another component order). A lot of textures do get converted to ARGB8888 as the games use 32-bit palettes for their paletted textures (which are the majority of textures in most games as the space savings are large).

[Mullin]

@hrydgard : I will investigate but Mali400 is known for texture corruption.

Check out : http://i48.tinypic.com/1zewg2v.png
http://forum.unity3d.com/attachments/screenshot_2013-09-05-12-09-38-png.66345 http://i49.tinypic.com/2hdbbk3.png

[Mullin]

@unknownbrackets @hrydgard : I'm totally wrong, this is a issue with Stencil Buffer.

[hrydgard]

@Mullin how do you know? Interestingly a few games show similar artifacts on nVidia Shield which appear to possibly be stencil-related.

[Mullin]

@hrydgard : By doing somes tests, Mali400 seem don't like 24 bits depth(Maybe Tegra 4 too), we should test with a 32 bits depth but this is really slower. Mali400 and Tegra 4 use a old architecture with lacks of many functions. We need somes hacks for make this working proprely.

This is exactly the same issue with Mali400 and Tegra 4.

[unknownbrackets]

Can we request a 16-bit stencil depth buffer at all on Mali-400? This would actually be better anyway.

-[Unknown]

[hrydgard]

No GPU I know of support 16-bit stencil, but I assume you mean a 16-bit Zbuffer and then a separate 8-bit stencil buffer. Which yes, should be possible. We actually use an extension to get the 24+8 buffer that we use now.. See native/gfx_es2/fbo.cpp , line 178+. I guess we could blacklist the OES_depth_24 and OES_packed_depth_stencil extensions on Mali..

[unknownbrackets]

Sorry, need to get more sleep, yes. Just wondering if that would improve rendering and not be too much of a perf hit. It might fix some depth rounding issues (we need to find a way to fix them though anyway...)

-[Unknown]

[Mullin]

Tested on mali but no luck. Try on Tegra 4. Work well on Adreno and PVR ?

We need somes tests on Adreno 220-225 and PVR SGX54X.

[unknownbrackets]

I don't remember any weird issues like that in games on my Adreno 225.

-[Unknown]

[Mullin]

@unknownbrackets @hrydgard : Mali400MP already use 16 bits Z-Buffer(24 bits fix doesn't affect Mali400MP), this is a stencil issue or something else. Don't understand why. I can confirm this is a Z-fighting issue on Tegra 4.

Mali400MP4 :
Outrun : Bug but work with PSP x1 before and after 24-bit Z bits fix.
Tekken 6 : Black screen before and after 24-bit Z bits fix.
FF Type-0 : Work before and after after 24-bit Z bits fix.

[S-Pawar]

this bug is also present on mali 450 didn't appear on powervr

[Gamemulatorer]

Naruto Shippuden Ultimate Ninja Impact

[unknownbrackets]

Was this the thing that was a confirmed driver bug?

-[Unknown]

[Gamemulatorer]

*Monsters Hunter 3rd Portable HD
*Gods Eater Burts
*Naruto Shippuden Ultimate Ninja Impact
all of that game in ppsspp has a grapical glitch in Mali-400 and Mali-450 GPU so it's a driver bug :( (imo)

[Gamemulatorer]

Hellboy The Science Of Evil

[Gamemulatorer]

Graphic bug also present in Lego Star Wars III, Toca Race Drive, Need For Speed Most Wanted and DISSIDIA Final Fantasy :(

@hrydgard Is there any possibility that this can be fixed or not ?

[unknownbrackets]

Unfortunately, this is a driver bug afaik, so the only way we might be able to fix it is if we could find a workaround to dodge it completely. Which might mean doing drawing a slower way, but I really don't know.

-[Unknown]

[Gamemulatorer]

Latest build still have this issue so this is probably unfixable :(

[Gamemulatorer]

Just an experimentation 😅

HARDWARE

SOFTWARE

I added Monster Hunter 3rd HD to ForceSoftwareRenderer compat and the graphics glitches is gone, but the game is very slow as expected also the fps is turn to 60 instead of 30.

[Gamemulatorer]

@hrydgard kindly add mali gpu label as this issue is only happen on mali400 series gpu

[unknownbrackets]

Software rendering always draws to your display at 60 FPS, unless you enable frameskipping (technically, so does the PSP.) In a 30 FPS game, it's just that every second frame is identical to the prior.

-[Unknown]

[Gamemulatorer]

Software rendering always draws to your display at 60 FPS, unless you enable frameskipping (technically, so does the PSP.) In a 30 FPS game, it's just that every second frame is identical to the prior.

-[Unknown]

@unknownbrackets game freeze when using frameskiping x1 or so during software rendering, why?

[unknownbrackets]

Hm, it may be a bug. Might be worth opening a separate issue with a few games that happens for - I know frameskip with the software renderer is not as heavily tested.

-[Unknown]