Shadows flickering white in Jet Set Radio Future

[Stevoisiak]

Quick summary

When playing Jet Set Radio Future, the screen will occasionally flicker white.

Details

While playing Jet Set Radio Future, on-screen shadows and characters will flicker white at seemingly random intervals. Sometimes it can happen every few seconds. This can occur on the title screen, on the character select screen, and during normal gameplay.

System Configuration:

• OS: Windows 10 Pro (20H2, build 19042.1165)
• CPU: AMD Ryzen 5 5600X 6-Core Processor
• GPU: NVIDIA GeForce GTX 1070
• GeForce Driver: 471.96
• CXBX Build: b405153
• Monitor: LG 27GL850, 2560 x 1440, 144hz, 125% scale

Additional Information (if any):

Screenshot:

Video:
https://www.youtube.com/watch?v=X4bu6PCHsQI (flickering starts at 0:55)

[ergo720]

I tried to reproduce the issue with my GTX 1050 and the build / settings you posted and I could not. JSRF is not known to have any graphical issues other than the broken graffiti, so this is very likely an issue on your end. Make sure you have not modified the xbe with the widescreen patch, which is known to introduce graphical artifacts. Also, this issue tracker does not accept game-specific issues anyway.

[PatrickvL]

Also, try clearing the symbol cache

[ergo720]

We got multiple users affected by this issue, and at least one case confirmed of not using the widescreen patch, so this seems to be a real issue now. However, none of the developers have yet managed to reproduce this.

[akjdssdfg]

Have this issue too and i can say that something happened in this build "CI-cec1b0b | Mon, May 17, 2021 3:55 PM" before this there is no flickering problem, after this all builds have it.

[VidarPT]

Have this issue too and i can say that something happened in this build "CI-cec1b0b | Mon, May 17, 2021 3:55 PM" before this there is no flickering problem, after this all builds have it.

Yes, from my experience the May 17th build is when the issue manifests too. The May 14th build is entirely flicker-free. I'm on a RX580, so I had to use DXVK, but the game looks flawless as far as my eyes can see.

[NZJenkins]

The commit: cec1b0b
Video from discord

[PatrickvL]

In this commit there's a kind reading if (Register >= X_D3DVSDE_VERTEX && Register <= X_VSH_MAX_ATTRIBUTES) {

Given that X_D3DVSDE_VERTEX is declared as integer -1, the above check will always fail. I vaguely remember this issue has been fixed later on, but still it might warrant a closer look?

EDIT : Above might not be correct - it's related to this review : #2215 (comment) which was actually fixed.

Though, from other feedback, the condition might have to exclude X_VSH_MAX_ATTRIBUTES (so : a change of <= into < might be needed).

[PatrickvL]

Alternatively, the mentioned commit also changed the number of components of all vertex attributes into 4, while before each attribute had it's own number of components (blend weight got only one float, position got 3, rhw was separate, etc).

While having more components than strictly required may not be a big issue of itself, perhaps some of these might have returned a default value for the components not present in the source - like, normally all components should give zero, except the fourth which may have been one (1).

If some shader expected those default values, and with the above mentioned commit, other values crept in, that may explain (part of) the issue.

...just my 5 cents tho.

[NZJenkins]

Might be worth checking if the IVB code is called by multiple threads in JSRF

[ergo720]

My answer here is still valid: if developers cannot reproduce it and/or are not affected by it, then it will never be fixed. This issue doesn't need more comments such as "This affects me too" "Issue still exists", because we already know it's a real issue, but we instead need "I looked into it, debugged it, and this is why it happens.". Until then, there's no hope that this will ever be fixed.

[tater1234]

In my experience, running on a AMD Ryzen 3 2200g with Radeon Vega graphics with 32 gb of DDR4, the issue is less prevalent in darker areas of the game where the usually only the players model/shadow will flash white. This might or might not help as much as I am not too savvy with code. But the issue may be related to how CXBXR is processing the position of shadows relative to the player as the issue may worsen when the player is moving at a higher speed moving through map.