Card Games - The Classics (Europe) corrupt graphics

[benderscruffy]

using 0.7.3
on the title screen and card selection screen the top screen the graphics are not correct and the same as your customize character screen

[Arisotura]

wow. this one is a shitshow.

either a really interesting CPU/emulation bug, or 'just' some timing bug again

[Arisotura]

woa. that game is also shitting itself on NO$GBA and DeSmuME, in the exact same fashion (corrupted textures).

yet, it works fine on hardware, confirming that the ROM is good.

that's interesting to say the least.

--

welp, that's a big stinky timing issue

it works fine in DeSmuME if you enable advanced timing.

oddly, it works the same in all melonDS versions that can run it.

--

it needs slow code timings, apparently. it looks okay if I set kCodeCacheTiming to 16.

[Arisotura]

the skinny:

• game uses a system to do things, that defers them until VBlank
• it requires that VCount be between 193 and 199 incl by the time it does its things (ie that IRQ handling and thread scheduling take one scanline worth of time)
• said system is used to upload textures and palettes

hence the bug.

this will likely require icache timings or some approximation.

[ghost]

It's all still completely fucked. The characters on the customization screen don't even render at all anymore.