Ppsspp: Metal Gear Solid Peace Walker Vulkan Rendering

[fivefeet8]

What happens?

Vulkan rendering is not right. Too bright with patches

What should happen?

Should look like the OpenGL render.

What hardware, operating system, and PPSSPP version? On desktop, GPU matters for graphical issues.

Android Snapdragon 820 ZTE Phone, PPSSPP Dev Ver 1.5.4-947

OpenGL Render:

Vulkan Render:

[leopard20]

Checking "Disable slower effects" fixes it though.

[leopard20]

@hrydgard
Silly question: Why is the game running @ 21/20 FPS but PPSSPP is showing a 99% speed?! 😅
Shouldn't it be 101~102% ?! 🙃

[fivefeet8]

@leopard20

That's more like a workaround. Slower effects worked fine before. Also, the game normally runs at 20 FPS ingame, but the FPS indicator fluctuates between 19 to 21. It's probably rounding errors in how the FPS value is calculated or the game slows down slightly depending on what's being rendered. In either case, you don't notice it while playing.

[fivefeet8]

Confirmed this happens on my Shield TV as well with PPSSPP dev 945.

[marosis]

If you want more FPS, you can try this FPS cheat code. _C0 Force 60 FPS beta
_L 0x2055DDB4 0x00000001
_L 0x203E7500 0x00000005
_L 0x203E74E4 0x3F800000
_C0 Force 30 FPS beta
_L 0x2055DDB4 0x00000002
_L 0x203E7500 0x0000000A
_L 0x203E74E4 0x40000000
_C0 Force 20 FPS beta
_L 0x2055DDB4 0x00000003
_L 0x203E7500 0x0000000F
_L 0x203E74E4 0x40400000

[marosis]

This is for eur version

[hrydgard]

did this start with the recent depal changes, or has it been like this for some time?

[leopard20]

If I recall correctly it was after the depal changes. Will test later.

[hrydgard]

If you're building yourself, you can use the latest version and try modifying this line in TextureCacheVulkan.cpp to false:

https://github.com/hrydgard/ppsspp/pull/10911/files#diff-3e0e122df6d1f6394367a0fc6e8066d5R347

[leopard20]

No. Android studio is not downloadable here. I have a version of Eclipse but it's way too old (nearly 3-4 years!)

Anyway build 896 works ok. Build 905 doesn't.
So yeah. It's because of depal.

P.S: Is depalletization the same as deposterization?

[hrydgard]

Ok, good. I'll see what I can figure out, if it can't be fixed in time I'll just disable that new optimization for 1.6 and deal with it later.

No, the PSP GPU can do texturing where it looks up each texel in a palette (or CLUT), and when it does that using a framebuffer as a texture, we have to simulate that by looking up every color in a palette in a shader. We used to do this by running a shader pass to "depalettize" the whole frame buffer to a new texture, but with this change it's done on-the-fly instead which is usually faster. And also seems to have a new bug :)