3.3.6: OpenGL issue

[8Observer8]

Tools:

• Windows 10
• MinGW GCC 11.2
• Asus K53SV (2011) - It has two video cards: Intel 3000 (OpenGL 3.1) and GeForce 540M (OpenGL 4.6)
• SDL 3.3.6

The following example works well with SDL 3.2.28 but does not work with SDL 3.3.6:

main.c

#define SDL_MAIN_USE_CALLBACKS 1

#include <SDL3/SDL.h>
#include <SDL3/SDL_main.h>
#include <stdio.h>

#include <glad/glad.h>

static SDL_Window *window = NULL;
static SDL_GLContext glContext = NULL;

SDL_AppResult SDL_AppInit(void **appstate, int argc, char *argv[])
{
    (void)appstate; (void)argc; (void)argv;

    if (!SDL_Init(SDL_INIT_VIDEO))
    {
        SDL_Log("SDL_Init failed: %s", SDL_GetError());
        return SDL_APP_FAILURE;
    }

    SDL_GL_SetAttribute(SDL_GL_MULTISAMPLEBUFFERS, 1); // Enable MULTISAMPLE
    SDL_GL_SetAttribute(SDL_GL_MULTISAMPLESAMPLES, 2); // Can be 2, 4, 8 or 16

    window = SDL_CreateWindow("OpenGL Version", 250, 250, SDL_WINDOW_OPENGL);
    if (!window)
    {
        SDL_Log("SDL_CreateWindow failed: %s", SDL_GetError());
        SDL_Quit();
        return SDL_APP_FAILURE;
    }

    glContext = SDL_GL_CreateContext(window);
    if (!glContext)
    {
        SDL_Log("SDL_GL_CreateContext failed: %s", SDL_GetError());
        SDL_DestroyWindow(window);
        SDL_Quit();
        return SDL_APP_FAILURE;
    }

    SDL_GL_SetSwapInterval(1); // Turn on vertical sync

    if (!gladLoadGL())
    {
        SDL_Log("Failed to initialize OpenGL function pointers");
        return SDL_APP_FAILURE;
    }

    glClearColor(0.2f, 0.5f, 0.3f, 1.0f);

    // Print SDL versions
    printf("Compiled SDL3 version: %d.%d.%d\n",
        SDL_MAJOR_VERSION,
        SDL_MINOR_VERSION,
        SDL_MICRO_VERSION);
    // Get the version of the SDL library linked at runtime
    int v = SDL_GetVersion();
    printf("Linked SDL3 version:   %d.%d.%d\n", SDL_VERSIONNUM_MAJOR(v),
        SDL_VERSIONNUM_MINOR(v), SDL_VERSIONNUM_MICRO(v));

    const char *glVersion = (const char *)glGetString(GL_VERSION);
    printf("OpenGL version:        %s\n", glVersion);

    return SDL_APP_CONTINUE;
}

SDL_AppResult SDL_AppIterate(void *appstate)
{
    (void)appstate;
    glClear(GL_COLOR_BUFFER_BIT);
    SDL_GL_SwapWindow(window);
    return SDL_APP_CONTINUE;
}

SDL_AppResult SDL_AppEvent(void *appstate, SDL_Event *event)
{
    (void)appstate;

    if (!event)
        return SDL_APP_CONTINUE;

    if (event->type == SDL_EVENT_QUIT)
        return SDL_APP_SUCCESS;

    return SDL_APP_CONTINUE;
}

void SDL_AppQuit(void *appstate, SDL_AppResult result)
{
    (void)appstate; (void)result;

    if (glContext)
        SDL_GL_DestroyContext(glContext);
    if (window)
        SDL_DestroyWindow(window);

    SDL_Quit();
}

I have built EXE with SDL 3.3.6 and replaced SDL3.dll (3.2.28 and 3.3.6) for testing. If you have an old laptop with two video cards (integrated and discrete) you can test it:

3.2.28

It works as expected with SDL3.dll v3.2.28:

opengl-version-sdl-3.2.28-c-exe.zip

3.3.6

It does not work as expected with SDL3.dll v3.3.6:

opengl-version-sdl-3.3.6-c-exe.zip

How to run the SDL 3.3.6 version on a laptop with two video cards:

1. Use this option:

2. Or add this code at the beginning of the main.c file:

__declspec(dllexport) unsigned long NvOptimusEnablement = 1;
__declspec(dllexport) unsigned long AmdPowerXpressRequestHighPerformance = 1;

Note. The first line is for GeForce. The second line is for Radeon. You can copy both - one of them will be ignored.

[8Observer8]

I have found that it was broken in 3.3.4!

It works with 3.3.2:

opengl-version-sdl-3.3.2-c-exe.zip

But it does not work with 3.3.4:

opengl-version-sdl-3.3.4-c-exe.zip

[icculus]

Does this only fail on the discrete GPU? The integrated one still works?

[8Observer8]

No, SDL 3.3.4 and SDL 3.3.6 fail on integrated (Intel 3000) only but they work well on discrete (GeForce 540M). SDL 3.2.28 and SDL 3.3.2 work well on both: integrated and discrete.

[slouken]

Are you able to use git bisect to determine what change broke this?

[8Observer8]

I did not use this tool before. But now I know how to use it. Thank you very much!

Result:

c6935f9dcb7068eb1aae8d18763357e249f93482 is the first bad commit
commit c6935f9dcb7068eb1aae8d18763357e249f93482
Author: Sam Lantinga <slouken@libsdl.org>
Date:   Sat Nov 15 07:43:59 2025 -0800

    Fixed EGL framebuffer colors on AMD drivers

 src/video/windows/SDL_windowsopengl.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

c6935f9

My steps (helped with ChatGPT):

1. Init:

git clone https://github.com/libsdl-org/SDL.git
cd SDL
git tag | findstr release
git tag | findstr "3."
git bisect reset
git bisect start
// status: waiting for both good and bad commits
git bisect bad prerelease-3.3.4
// status: waiting for good commit(s), bad commit known
git bisect good preview-3.3.2
//Bisecting: 196 revisions left to test after this (roughly 8 steps)
//[e2e8f86076a815303836514bb4ba661a84532d24] Check for wine_get_version() to detect Wine/Proton

2. Loop:

rmdir /s /q dist
cmake -G "MinGW Makefiles" -S . -B dist -DCMAKE_INSTALL_PREFIX="H:/projects/opengl/sdl3-bisect-mingw" -DCMAKE_BUILD_TYPE=MinSizeRel
cmake --build dist -j4
cmake --install dist
config-exe
build-exe
run-exe

3. Full Result:

>git bisect good
Bisecting: 98 revisions left to test after this (roughly 7 steps)
[ebd3aa528920bdd9e6e9725a0f3acb63c9d41d4a] testgpu_spinning_cube: fixed error handling if texture creation fails
>git bisect bad
Bisecting: 48 revisions left to test after this (roughly 6 steps)
[168f78b8b76c4a91cd744b03a816613a8273e250] wayland: Free the cursors before stopping the event thread
>git bisect bad
Bisecting: 24 revisions left to test after this (roughly 5 steps)
[b83bd80424dd5251747a8b696157c06d2fcc303f] Update README.md
>git bisect bad
Bisecting: 11 revisions left to test after this (roughly 4 steps)
[cc3b5766fa14bbc182e0f5fe21c0f1454b66a731] testsprite: changed return type of LoadSprite() to bool
>git bisect good
Bisecting: 5 revisions left to test after this (roughly 3 steps)
[0f763da0152da745b93a8138e7c592df625eb2eb] Sync SDL3 wiki -> header
>git bisect good
Bisecting: 2 revisions left to test after this (roughly 2 steps)
[005cb20e67529dcb24ee799a5f270f55b03f6bd7] wayland: Use defines for timer rollover constants
>git bisect bad
Bisecting: 0 revisions left to test after this (roughly 1 step)
[c6935f9dcb7068eb1aae8d18763357e249f93482] Fixed EGL framebuffer colors on AMD drivers
>git bisect bad
Bisecting: 0 revisions left to test after this (roughly 0 steps)
[a4c269cd103c34e77c71c23e1522d2537c5a1cb3] Fixed handling framebuffer_srgb_capable for EGL and iOS
>git bisect good
c6935f9dcb7068eb1aae8d18763357e249f93482 is the first bad commit
commit c6935f9dcb7068eb1aae8d18763357e249f93482
Author: Sam Lantinga <slouken@libsdl.org>
Date:   Sat Nov 15 07:43:59 2025 -0800

    Fixed EGL framebuffer colors on AMD drivers

 src/video/windows/SDL_windowsopengl.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)```

Source code: opengl-version-opengl2-sdl3-c.zip

[icculus]

Man, this sRGB attribute is going to be the death of us all.

[icculus]

Can we figure out if this system is setting the attribute to GL_TRUE or GL_FALSE?

[icculus]

This is working for me (on Windows in VirtualBox, at least)...

I'm inclined to call this a driver bug on an old machine. I'm not sure if we should try to check for extremely old driver versions and force a specific sRGB value (or disable the extension outright) or just leave this be.

[icculus]

I'm now thinking that my VirtualBox doesn't have the sRGB extension (GL version 1.1?! Software renderer, I assume), fwiw, so I'm not sure it's going to be representative of the world at large, I don't know.

Also, the original screenshots had driver version 9.17.10.4459...it looks like the Intel 3000 Win10 drivers maxed out at 15.40.1.64.4256.

https://www.intel.com/content/www/us/en/download/18338/intel-hd-graphics-production-driver-for-windows-10-64-bit-n-series.html

I don't know if you can just install that to upgrade a random laptop, but it might be worth trying.