Linux PowerPC: Endian issues

[chzigotzky]

Hello,

Thanks a lot for wipEout Rewrite! :-)

I was able to compile it on ubuntu MATE 16.04.7 PowerPC today. It starts but it has wrong colors and the sound isn't correct. I think it is an endian issue because Linux PowerPC runs on big endian machines. I tested it on Void PPC as well but unfortunately it has the same issues on it. Is it possible to fix these issues?

Screenshot:

Thanks, Christian

[Jamesf4]

Littlebit but still Cool

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จาก: Christian Zigotzky @.> ส่ง: Monday, August 28, 2023 11:29:26 AM ถึง: phoboslab/wipeout-rewrite @.> สำเนาถึง: Subscribed @.***> ชื่อเรื่อง: [phoboslab/wipeout-rewrite] Linux PowerPC: Endian issues (Issue #56)

Hello,

Thanks a lot for wipEout Rewrite! :-)

I was able to compile it on ubuntu MATE 16.04.7 PowerPC today. It starts but it has wrong colors and the sound isn't correct. I think it is an endian issue because Linux PowerPC runs on big endian machines. I tested it on Void PPC as well but unfortunately it has the same issues on it. Is it possible to fix these issues?

Screenshot:

[wipEout_Rewrite_Linux_PowerPC]https://user-images.githubusercontent.com/43322007/263642597-48cd5647-0075-4f36-8cbd-69bce55a5976.png

Thanks, Christian

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[phoboslab]

Very cool to see that you got it running at all!

Questions:

• does the music work and only sound effects are garbled?
• do you see the title screen in the correct colors?

The title screen is in straight 16bit colors, while most (all?) of the textures are paletted. I assume reading the colors from the palette isn't endian agnostic. The palette lookup seems to work though.

I have a harder time to understand where the sound issues come from. The wipeout.vb file with all the samples is read one byte at a time. If there's issues with the music, there is probably a bug in the QOA decoder itself. You can change the volume of sound effects and music in the main options to check what exactly is broken.

[phoboslab]

Above commit should fix this color issues. Let me know if it works! :]

[chzigotzky]

Thanks for your fast answer. The color issue is partly fixed with your commit. :-)

Music and sound effects are both garbled.

[BeWorld2018]

Thanks for this fix, I had the same problem under MorphOS PPC.

For audio, you can modify this : https://github.com/phoboslab/wipeout-rewrite/blob/master/src/platform_sdl.c#L393 Put AUDIO_F32SYS (https://wiki.libsdl.org/SDL2/SDL_AudioFormat)

[chzigotzky]

Yes, the audio fix works! :-) Thanks!

There are still some color issues.

[phoboslab]

Thanks for the audio fix @BeWorld2018 and thanks for all the screenshots @chzigotzky; it helps a lot.

The 4bpp textures seem to work now, but the 8bpp track textures are still wrong and I can't figure out why. It's almost the same code for 4bpp and 8bpp...

[phoboslab]

I suspect I was overly smart; trying to swap the palette in-place. Which doesn't work when the whole get_u16_le() function is inlined. Hope that was it :]

[chzigotzky]

Many thanks for your help! :-) The colors partly arent't correct but it looks really better.

[BeWorld2018]

In my side, i use OpenGL Legacy renderer from unoffical repository : https://github.com/mrneo240/wipeout-rewrite/blob/master/src/render_gl_legacy.c but i have some problem with colors, i think i's better now but not perfect :

with MorphOS (PPC):

with Windows (same renderer):

[phoboslab]

Texture loading seems to work now, but the vertex colors for the track are backwards!? I'm looking into it.

Also, judging from the trees, this legacy OpenGL renderer is missing a glEnable(GL_ALPHA_TEST) :]

[BeWorld2018]

Also, judging from the trees, this legacy OpenGL renderer is missing a glEnable(GL_ALPHA_TEST) :]

You right, i put that and tree are now correct, thanks

[phoboslab]

Well, I can't find anything wrong with the texture loading and I have no way to test big endian machines. Is there maybe some way I can do this in a VM?

Also, if you have a minute, can you please try and change this line from

vec4 color = tex_color * v_color;

to

vec4 color = v_color;

This will disable texture rendering. If you then enter the game, we can at least check if a) the vertex colors are wrong or b) it's still the texture loading.

[chzigotzky]

I have changed the line and compiled it again. Result:

[phoboslab]

Thanks for the screenshot! So it was the vertex colors and initializing them with rgba_t color = {.as_uint32 = get_i32_le(bytes, &p) | 0xff000000}; obviously didn't work. Above commit should fix that.

I will clean up the code a little and get rid of the .as_uint32 union completely. I believe that was the only instance it was used anyway.

[chzigotzky]

The colors are all correct! Thanks a lot! :-) I compiled it on an old ubuntu MATE 16.04.7 PowerPC and it works without any problems. I also compiled and tested it on Void PPC and on a new Debian Sid PPC but unfortunately the sound stutters sometimes.

[chzigotzky]

The intro video also stutters on Void PPC and Debian PPC. An SDL issue?

They don't stutter on the old ubuntu MATE 16.04.7 PowerPC.

[phoboslab]

Sound stuttering can maybe be fixed by increasing the buffer size here at the cost of some sound latency. Try setting it to .samples = 4096, or even higher. Let me know if that helps; I can add that as in-game option.

As for the video: how's the CPU load during the intro?

[chzigotzky]

Thank you very much for your answer! Unfortunately, setting it to .samples = 4096 does not solve the stuttering problem. Even a higher level does not solve the problem.

During the stuttering the CPU load is about 90%.

[BeWorld2018]

For me, i adapt OpenGL legacy render, and color seem ok here tooo (compare to Windows version) Now compare to OpenGL 3 renderere, there are some difference... but it's not your problem

Result MorphOS/Windows with OpenGL legacy 👍 (Track border seem yellow instead of purple)

Thanks again !

[chzigotzky]

When I start a race, the sound stutters and the CPU usage increases to 90%. A short time later, the stuttering goes away and the CPU usage decreases.

Maybe I should test it with the libsdl2 from ubuntu MATE 16.04.7. (LD_LIBRARY_PATH)

[phoboslab]

Result MorphOS/Windows with OpenGL legacy 👍 (Track border seem yellow instead of purple)

Not really sure what's going on with the track colors, but the color blotches in the audience stands could be from an overflow!? I think this:

uint8_t R = tris.vertices[i].color.as_rgba.r;
uint8_t G = tris.vertices[i].color.as_rgba.g;
uint8_t B = tris.vertices[i].color.as_rgba.b;
if(R == 128){
    R = 255;
} else {
    R *=2;
}
if(G == 128){
    G = 255;
} else {
    G *=2;
}
if(B == 128){
    B = 255;
} else {
    B *=2;
}
tris.vertices[i].color.as_rgba.r = R;
tris.vertices[i].color.as_rgba.g = G;
tris.vertices[i].color.as_rgba.b = B;

should just be (sans as_rgba as removed in a commit today)

tris.vertices[i].color.r = clamp(tris.vertices[i].color.r * 2, 0, 255);
tris.vertices[i].color.g = clamp(tris.vertices[i].color.g * 2, 0, 255);
tris.vertices[i].color.b = clamp(tris.vertices[i].color.b * 2, 0, 255);

Or glColorPointer() needs to be float and you divide all color values by 128.0. For whatever reason wipEout mostly seems to use the 0..128 color range, but then sometimes exceeds it with > 128 "whiter than white" overbright values.

[BeWorld2018]

You right on first solution ! Thanks again ;-)

[chzigotzky]

I have found the issue. -> A L T I V E C

We have stuttering on Void PPC on a Non-AltiVec PowerPC machine. (FSL P50x0)

We don't have stuttering on Void PPC on a PowerPC machine with a SoC with AltiVec support. (P.A. Semi PA6T)

It seems the libs on ubuntu MATE 16.04.7 PowerPC aren't compiled with AltiVec support so wipEout runs without stuttering on a Non-AltiVec PowerPC machine.

Is it possible to compile a static wipEout binary (.a)? Maybe this is a solution.

[chzigotzky]

Hi BeWorld,

Congratulations! Maybe I should test the OpenGL Legacy renderer version as well.

Could you please share your modified source code of the OpenGL Legacy renderer version?

Thanks, Christian

[chzigotzky]

Hi All,

I patched the OpenGL Legacy renderer version and it runs without any stuttering on Void PPC on my Non-AltiVec PowerPC machine.

There are some graphical issues for example missing transparency.

[BeWorld2018]

hi,

On this file: https://github.com/mrneo240/wipeout-rewrite/blob/master/src/render_gl_legacy.c

i just add after line 114 glEnable(GL_ALPHA_TEST); And add patch:

void render_push_tris(tris_t tris, uint16_t texture_index) {
    error_if(texture_index >= textures_len, "Invalid texture %d", texture_index);

    if (tris_len >= RENDER_TRIS_BUFFER_CAPACITY) {
        render_flush();
    }
    if(texture_index != texture_index_prev){
        render_flush();
    }
    texture_index_prev = texture_index;

    render_texture_t *t = &textures[texture_index];

    for (int i = 0; i < 3; i++) {

        // resize back to (0,1) uv space
        tris.vertices[i].uv.x = (tris.vertices[i].uv.x / t->size.x) * t->scale.x;
        tris.vertices[i].uv.y = (tris.vertices[i].uv.y / t->size.y) * t->scale.y;
        if(tris.vertices[i].color.a == 0){
            continue;
        }
        tris.vertices[i].color.r = clamp(tris.vertices[i].color.r * 2, 0, 255);
        tris.vertices[i].color.g = clamp(tris.vertices[i].color.g * 2, 0, 255);;
        tris.vertices[i].color.b = clamp(tris.vertices[i].color.b * 2, 0, 255);;

    }
    tris_buffer[tris_len++] = tris;
}

And i add patch to release textures when exit game:

void render_cleanup(void) {
    // TODO
    render_textures_reset(render_textures_len());

}

[chzigotzky]

Hi BeWorld,

Thanks a lot for your answer. I modified the render_gl_legacy.c with your changes and compiled it again.

Unfortunately, the issue with the missing transparency still exist. (see my last screenshot)

Thanks, Christian

[chzigotzky]

BeWorld,

Have you applied all patches from phoboslab to the OpenGL Legacy renderer version?

Thanks, Christian

[BeWorld2018]

i recompare my file with original opengl legacy and all difference are mentioned in my reply.

[chzigotzky]

BeWorld,

Thanks for your answer. It works with the correct colors and sound now! :-)

Many thanks to all! :-)

Cheers, Christian

[chzigotzky]

It works with the correct colors and without sound stutters with my AMD Radeon HD6970 (Cayman XT).

Unfortunately it has color issues with the ATi Radeon X1900 XT (R580):

[madskateman]

It works with the correct colors and without sound stutters with my AMD Radeon HD6970 (Cayman XT).

Unfortunately it has color issues with the ATi Radeon X1900 XT (R580):

On this PPC machine the BeWorld MorphOS port is working perfect. So the X1900 (R580) GPU is ok.

https://www.skateman.nl/wp-content/uploads/2023/09/MOS_WIPEOUT.jpg

[phoboslab]

Closing this issue. The problems that remain seem to be driver specific. Feel free to open another issue if you find more problems with the game itself.