Duke Nukem: Land of the Babes (USA), weird graphical glitch while underwater.

[valter12437]

This happens everytime you go in any underwater area in the game: I'm using PCSX-ReARMed (r23l aced3eb) on Windows 10 Home trough RetroArch.

[pcercuei]

@valter12437 Do you have a savestate you could share to reproduce the problem?

[valter12437]

@pcercuei sure, here it goes. Just load the state and jump into the pool. Alternatively, select the training stage, go to the pool area and jump in.

Duke Nukem - Land of the Babes (USA).zip

[m4xw]

Took me 1.5 days but i tracked it to this OP https://github.com/libretro/pcsx_rearmed/blob/master/plugins/gpu_unai/gpulib_if.cpp#L748 Not sure why yet but stubbing it fixes it for unai, will investigate further tomorrow, up for ideas if anyone has

[m4xw]

On another note i also fixed unit tests on some GTE ops but guess will handle that seperately since it didnt turn out to be that

[m4xw]

This appears to fix it, might be a off-by-one in all gpu plugins? AFAIK this effect works on hardware, but this seems like a weird oversight if u ask me, at least silently discarding it doesnt do the trick in this case It does set those params as well and sends data with those locations in mind so that would check out. peops had same issue as unai here but neon gpu was more funky, I hope you know whats going on here, @notaz Also if u look at the original image theres some shenanigans at the right edge etc so thats also reaffirming

[m4xw]

Double checking against using 511/1023 and using the top codepath with >= for them still is broken, so appears to me this needs indeed 1024/512

[pcercuei]

Using 512/1024 does make absolutely zero sense, though.

[m4xw]

As far i can tell from the games code it looks to be doing some offscreen vertices

[pcercuei]

What do you get if you print x0 / y0 / x1 / y1 / w0 / h0? Is that your screenshot with the "set drawing area" messages?

[m4xw]

The screenshot was this

[m4xw]

Here i just dumped the umasked vals for one frame:

x0: 512, y0: 2, x1: 511, y1: 2, w0: 512, h0: 2
x0: 512, y0: 4, x1: 511, y1: 4, w0: 512, h0: 2
x0: 512, y0: 6, x1: 511, y1: 6, w0: 512, h0: 2
x0: 512, y0: 8, x1: 511, y1: 8, w0: 512, h0: 2
x0: 512, y0: 10, x1: 511, y1: 10, w0: 512, h0: 2
x0: 512, y0: 12, x1: 510, y1: 12, w0: 512, h0: 2
x0: 512, y0: 14, x1: 510, y1: 14, w0: 512, h0: 2
x0: 512, y0: 16, x1: 510, y1: 16, w0: 512, h0: 2
x0: 512, y0: 18, x1: 510, y1: 18, w0: 512, h0: 2
x0: 512, y0: 20, x1: 510, y1: 20, w0: 512, h0: 2
x0: 512, y0: 22, x1: 510, y1: 22, w0: 512, h0: 2
x0: 512, y0: 24, x1: 509, y1: 24, w0: 512, h0: 2
x0: 512, y0: 26, x1: 509, y1: 26, w0: 512, h0: 2
x0: 512, y0: 28, x1: 509, y1: 28, w0: 512, h0: 2
x0: 512, y0: 30, x1: 509, y1: 30, w0: 512, h0: 2
x0: 512, y0: 32, x1: 509, y1: 32, w0: 512, h0: 2
x0: 512, y0: 34, x1: 509, y1: 34, w0: 512, h0: 2
x0: 512, y0: 36, x1: 508, y1: 36, w0: 512, h0: 2
x0: 512, y0: 38, x1: 508, y1: 38, w0: 512, h0: 2
x0: 512, y0: 40, x1: 508, y1: 40, w0: 512, h0: 2
x0: 512, y0: 42, x1: 508, y1: 42, w0: 512, h0: 2
x0: 512, y0: 44, x1: 508, y1: 44, w0: 512, h0: 2
x0: 512, y0: 46, x1: 508, y1: 46, w0: 512, h0: 2
x0: 512, y0: 48, x1: 508, y1: 48, w0: 512, h0: 2
x0: 512, y0: 50, x1: 508, y1: 50, w0: 512, h0: 2
x0: 512, y0: 52, x1: 508, y1: 52, w0: 512, h0: 2
x0: 512, y0: 54, x1: 508, y1: 54, w0: 512, h0: 2
x0: 512, y0: 56, x1: 508, y1: 56, w0: 512, h0: 2
x0: 512, y0: 58, x1: 508, y1: 58, w0: 512, h0: 2
x0: 512, y0: 60, x1: 508, y1: 60, w0: 512, h0: 2
x0: 512, y0: 62, x1: 508, y1: 62, w0: 512, h0: 2
x0: 512, y0: 64, x1: 508, y1: 64, w0: 512, h0: 2
x0: 512, y0: 66, x1: 508, y1: 66, w0: 512, h0: 2
x0: 512, y0: 68, x1: 508, y1: 68, w0: 512, h0: 2
x0: 512, y0: 70, x1: 508, y1: 70, w0: 512, h0: 2
x0: 512, y0: 72, x1: 508, y1: 72, w0: 512, h0: 2
x0: 512, y0: 74, x1: 508, y1: 74, w0: 512, h0: 2
x0: 512, y0: 76, x1: 508, y1: 76, w0: 512, h0: 2
x0: 512, y0: 78, x1: 508, y1: 78, w0: 512, h0: 2
x0: 512, y0: 80, x1: 508, y1: 80, w0: 512, h0: 2
x0: 512, y0: 82, x1: 508, y1: 82, w0: 512, h0: 2
x0: 512, y0: 84, x1: 508, y1: 84, w0: 512, h0: 2
x0: 512, y0: 86, x1: 508, y1: 86, w0: 512, h0: 2
x0: 512, y0: 88, x1: 508, y1: 88, w0: 512, h0: 2
x0: 512, y0: 90, x1: 508, y1: 90, w0: 512, h0: 2
x0: 512, y0: 92, x1: 508, y1: 92, w0: 512, h0: 2
x0: 512, y0: 94, x1: 508, y1: 94, w0: 512, h0: 2
x0: 512, y0: 96, x1: 509, y1: 96, w0: 512, h0: 2
x0: 512, y0: 98, x1: 509, y1: 98, w0: 512, h0: 2
x0: 512, y0: 100, x1: 509, y1: 100, w0: 512, h0: 2
x0: 512, y0: 102, x1: 509, y1: 102, w0: 512, h0: 2
x0: 512, y0: 104, x1: 509, y1: 104, w0: 512, h0: 2
x0: 512, y0: 106, x1: 509, y1: 106, w0: 512, h0: 2
x0: 512, y0: 108, x1: 510, y1: 108, w0: 512, h0: 2
x0: 512, y0: 110, x1: 510, y1: 110, w0: 512, h0: 2
x0: 512, y0: 112, x1: 510, y1: 112, w0: 512, h0: 2
x0: 512, y0: 114, x1: 510, y1: 114, w0: 512, h0: 2
x0: 512, y0: 116, x1: 510, y1: 116, w0: 512, h0: 2
x0: 512, y0: 118, x1: 510, y1: 118, w0: 512, h0: 2
x0: 512, y0: 120, x1: 511, y1: 120, w0: 512, h0: 2
x0: 512, y0: 122, x1: 511, y1: 122, w0: 512, h0: 2
x0: 512, y0: 124, x1: 511, y1: 124, w0: 512, h0: 2
x0: 512, y0: 126, x1: 511, y1: 126, w0: 512, h0: 2
x0: 512, y0: 128, x1: 511, y1: 128, w0: 512, h0: 2
x0: 512, y0: 140, x1: 513, y1: 140, w0: 512, h0: 2
x0: 512, y0: 142, x1: 513, y1: 142, w0: 512, h0: 2
x0: 512, y0: 144, x1: 513, y1: 144, w0: 512, h0: 2
x0: 512, y0: 146, x1: 513, y1: 146, w0: 512, h0: 2
x0: 512, y0: 148, x1: 513, y1: 148, w0: 512, h0: 2
x0: 512, y0: 150, x1: 513, y1: 150, w0: 512, h0: 2
x0: 512, y0: 152, x1: 514, y1: 152, w0: 512, h0: 2
x0: 512, y0: 154, x1: 514, y1: 154, w0: 512, h0: 2
x0: 512, y0: 156, x1: 514, y1: 156, w0: 512, h0: 2
x0: 512, y0: 158, x1: 514, y1: 158, w0: 512, h0: 2
x0: 512, y0: 160, x1: 514, y1: 160, w0: 512, h0: 2
x0: 512, y0: 162, x1: 514, y1: 162, w0: 512, h0: 2
x0: 512, y0: 164, x1: 515, y1: 164, w0: 512, h0: 2
x0: 512, y0: 166, x1: 515, y1: 166, w0: 512, h0: 2
x0: 512, y0: 168, x1: 515, y1: 168, w0: 512, h0: 2
x0: 512, y0: 170, x1: 515, y1: 170, w0: 512, h0: 2
x0: 512, y0: 172, x1: 515, y1: 172, w0: 512, h0: 2
x0: 512, y0: 174, x1: 515, y1: 174, w0: 512, h0: 2
x0: 512, y0: 176, x1: 515, y1: 176, w0: 512, h0: 2
x0: 512, y0: 178, x1: 515, y1: 178, w0: 512, h0: 2
x0: 512, y0: 180, x1: 515, y1: 180, w0: 512, h0: 2
x0: 512, y0: 182, x1: 515, y1: 182, w0: 512, h0: 2
x0: 512, y0: 184, x1: 515, y1: 184, w0: 512, h0: 2
x0: 512, y0: 186, x1: 515, y1: 186, w0: 512, h0: 2
x0: 512, y0: 188, x1: 515, y1: 188, w0: 512, h0: 2
x0: 512, y0: 190, x1: 515, y1: 190, w0: 512, h0: 2
x0: 512, y0: 192, x1: 515, y1: 192, w0: 512, h0: 2
x0: 512, y0: 194, x1: 515, y1: 194, w0: 512, h0: 2
x0: 512, y0: 196, x1: 515, y1: 196, w0: 512, h0: 2
x0: 512, y0: 198, x1: 515, y1: 198, w0: 512, h0: 2
x0: 512, y0: 200, x1: 515, y1: 200, w0: 512, h0: 2
x0: 512, y0: 202, x1: 515, y1: 202, w0: 512, h0: 2
x0: 512, y0: 204, x1: 515, y1: 204, w0: 512, h0: 2
x0: 512, y0: 206, x1: 515, y1: 206, w0: 512, h0: 2
x0: 512, y0: 208, x1: 515, y1: 208, w0: 512, h0: 2
x0: 512, y0: 210, x1: 515, y1: 210, w0: 512, h0: 2
x0: 512, y0: 212, x1: 515, y1: 212, w0: 512, h0: 2
x0: 512, y0: 214, x1: 515, y1: 214, w0: 512, h0: 2
x0: 512, y0: 216, x1: 515, y1: 216, w0: 512, h0: 2
x0: 512, y0: 218, x1: 515, y1: 218, w0: 512, h0: 2
x0: 512, y0: 220, x1: 515, y1: 220, w0: 512, h0: 2
x0: 512, y0: 222, x1: 515, y1: 222, w0: 512, h0: 2
x0: 512, y0: 224, x1: 514, y1: 224, w0: 512, h0: 2
x0: 512, y0: 226, x1: 514, y1: 226, w0: 512, h0: 2
x0: 512, y0: 228, x1: 514, y1: 228, w0: 512, h0: 2
x0: 512, y0: 230, x1: 514, y1: 230, w0: 512, h0: 2
x0: 512, y0: 232, x1: 514, y1: 232, w0: 512, h0: 2
x0: 512, y0: 234, x1: 514, y1: 234, w0: 512, h0: 2
x0: 512, y0: 236, x1: 513, y1: 236, w0: 512, h0: 2
x0: 512, y0: 238, x1: 513, y1: 238, w0: 512, h0: 2

....
    x0 = packet.U2[2];
    y0 = packet.U2[3];
    x1 = packet.U2[4];
    y1 = packet.U2[5];
    w0 = packet.U2[6];
    h0 = packet.U2[7];

    if( (x0==x1) && (y0==y1) ) return;
    if ((w0<=0) || (h0<=0)) return;

    printf("x0: %d, y0: %d, x1: %d, y1: %d, w0: %d, h0: %d\n", x0, y0, x1, y1, w0, h0);
    fflush(stdout);
....

[m4xw]

Side Note: When i open the menu ingame (and it doesnt apply the caustic effect underwater) then it never invokes moveImage to begin with so the issue never appears

[m4xw]

Btw i could give some further insight if you contact me on discord i cant say too much on github due to circumstances m4xw#1560

[pcercuei]

The values look OK. I think it's just the algorithm that does not work properly with these values. It looks like the game tries to move lines of the framebuffer left and right to give it a wobble "underwater" effect. In the case where x1 > x0, the algorithm will actually copy pixel N[i] to N[i + n], which only works if you copy less than n pixels.

[m4xw]

The wobble effect doesnt happen with my change as far i can tell (checking over RDP rn and its a blurry mess)

[m4xw]

I do have some indication this might be abusing either a bug or a edge case to get the effect without the artifact, it works on beetle-psx fwiw

[Squall-Leonhart]

@Nucleoprotein do you have an idea here?

[pcercuei]

The bug seems to occur in all GPU plugins (neon, peops, unai).

The problem is that the VRAM->VRAM copy does not handle the case where the source and destination overlap.

One workaround in Unai is to copy the source to an intermediate buffer first:

diff --git a/plugins/gpu_unai/gpu_raster_image.h b/plugins/gpu_unai/gpu_raster_image.h
index 0c82aa97..31ad2692 100644
--- a/plugins/gpu_unai/gpu_raster_image.h
+++ b/plugins/gpu_unai/gpu_raster_image.h
@@ -81,14 +81,19 @@ INLINE void gpuMoveImage(void)
        if( (x0==x1) && (y0==y1) ) return;
        if ((w0<=0) || (h0<=0)) return;

-       if (((y0+h0)>512)||((x0+w0)>1024)||((y1+h0)>512)||((x1+w0)>1024))
+       if (1)
        {
                u16 *psxVuw=GPU_FrameBuffer;
                s32 i,j;
-           for(j=0;j<h0;j++)
-                for(i=0;i<w0;i++)
-                 psxVuw [(1024*((y1+j)&511))+((x1+i)&0x3ff)]=
-                  psxVuw[(1024*((y0+j)&511))+((x0+i)&0x3ff)];
+               u16 *tmp = (u16 *)alloca(sizeof(*tmp) * w0 * h0);
+
+               for (j = 0; j < h0; j++)
+                       for (i = 0; i < w0; i++)
+                               tmp[j * w0 + i] = psxVuw[1024*((y0+j)&511)+((x0+i)&0x3ff)];
+
+               for (j = 0; j < h0; j++)
+                       for (i = 0; i < w0; i++)
+                               psxVuw[1024*((y1+j)&511)+((x1+i)&0x3ff)] = tmp[j * w0 + i];
        }
        else if ((x0&1)||(x1&1))
        {

Of course this isn't very optimized, but at least it works.

[Squall-Leonhart]

The bug seems to occur in all GPU plugins (neon, peops, unai).

It doesn't occur in Kazzuya Soft

[notaz]

This should be fixed now. Many thanks to everyone who helped debugging this and posted info.

[pcercuei]

@notaz, your commit 36da9c1305 breaks Looney Tunes Sheep Raider. When trying to enter the very first level, the loading screen will never complete. I have no idea how it can be related; but reverting this commit on master fixes it.

[m4xw]

Also I got told unai broke as well (may or may not be related to that commit)

[pcercuei]

@m4xw broke how? We're using Unai and I didn't notice breakages related to this commit.

[notaz]

When trying to enter the very first level, the loading screen will never complete

Well it actually completed but it wasn't visible because I forgot to mark the fb for flipping. It should be fixed now.

[m4xw]

Duke TTK (Corruption on startup)

https://github.com/notaz/pcsx_rearmed/assets/13141469/6e0182cd-ec2e-4016-bb2b-62b933ebd810

[m4xw]

Dunno whats up with the video so heres another upload https://m4xw.net/nextcloud/index.php/s/akMMf2diqQYsZ7M Edit: Actually seems to not playback too, wth. Anyway theres a flicker happening Actually seems to work in VLC, weird.

[Ploggy]

The flickering is to do with Unai's Dithering, turn it off and the flickering will stop.