ES3, SDL & Emscripten

[キャロウ マーク]

I have an app that uses OpenGL ES3 and SDL2. When I try to run it I get "Could not create GLES window surface” which is coming from SDL. The app works fine natively on iOS, macOS, Linux and Windows. I’m having trouble getting source map debugging set up so am struggling a bit to figure out what’s wrong. Does anyone have any thoughts?

Regards

-Mark

[キャロウ マーク]

On Jul 19, 2019, at 17:38, キャロウ　マーク <git...@callow.im> wrote:

I have an app that uses OpenGL ES3 and SDL2. When I try to run it I get "Could not create GLES window surface” which is coming from SDL. The app works fine natively on iOS, macOS, Linux and Windows. I’m having trouble getting source map debugging set up so am struggling a bit to figure out what’s wrong. Does anyone have any thoughts?

Here is the SDL_CreateWindow call that is failing.

    SDL_GL_SetAttribute(SDL_GL_CONTEXT_PROFILE_MASK, SDL_GL_CONTEXT_PROFILE_ES);

    SDL_GL_SetAttribute(SDL_GL_CONTEXT_MAJOR_VERSION, 3);

    SDL_GL_SetAttribute(SDL_GL_CONTEXT_MINOR_VERSION, 0);

    SDL_GL_SetAttribute(SDL_GL_FRAMEBUFFER_SRGB_CAPABLE, 1);

#if defined(DEBUG)

    SDL_GL_SetAttribute(SDL_GL_CONTEXT_FLAGS, SDL_GL_CONTEXT_DEBUG_FLAG);

#endif

    

    pswMainWindow = SDL_CreateWindow(

                        szName,

                        SDL_WINDOWPOS_UNDEFINED,

                        SDL_WINDOWPOS_UNDEFINED,

                        w_width, w_height,

                        SDL_WINDOW_OPENGL | SDL_WINDOW_RESIZABLE

                    );

[キャロウ マーク]

On Jul 19, 2019, at 18:40, キャロウ　マーク <git...@callow.im> wrote:

Here is the SDL_CreateWindow call that is failing.

    SDL_GL_SetAttribute(SDL_GL_CONTEXT_PROFILE_MASK, SDL_GL_CONTEXT_PROFILE_ES);

    SDL_GL_SetAttribute(SDL_GL_CONTEXT_MAJOR_VERSION, 3);

    SDL_GL_SetAttribute(SDL_GL_CONTEXT_MINOR_VERSION, 0);

    SDL_GL_SetAttribute(SDL_GL_FRAMEBUFFER_SRGB_CAPABLE, 1);

#if defined(DEBUG)

    SDL_GL_SetAttribute(SDL_GL_CONTEXT_FLAGS, SDL_GL_CONTEXT_DEBUG_FLAG);

#endif

    

    pswMainWindow = SDL_CreateWindow(

                        szName,

                        SDL_WINDOWPOS_UNDEFINED,

                        SDL_WINDOWPOS_UNDEFINED,

                        w_width, w_height,

                        SDL_WINDOW_OPENGL | SDL_WINDOW_RESIZABLE

                    );

SDL_GL_FRAMEBUFFER_SRGB_CAPABLE and SDL_GL_CONTEXT_DEBUG_FLAG are the issues here. Except they shouldn’t be. The SDL_GL_SetAttribute documentation says these settings are *requests* and apps must use SDL_GL_GetAttribute after window and context creation to see if those features are available. It looks like a bug in the Emscripten SDL2 port that window creation is failing.

Regards

    -Mark

[Gabriel Cuvillier]

Hi,

I had a similar issue, and it is probably a bug:

With the SDL2 port to Emscripten, most SDL_GL_SetAttribute(SDL_GL_CONTEXT_FLAGS*) calls after SDL_GL_CONTEXT_PROFILE_MASK and MAJOR/MINOR will make things fail...

So you need to remove SDL_GL_CONTEXT_FLAGS call, and probably the SDL_GL_FRAMEBUFFER_SRGB_CAPABLE (or put it before the calls to PROFILE_MASK/MAJOR/MINOR)

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[キャロウ マーク]

On Jul 22, 2019, at 22:22, Gabriel Cuvillier <gabriel....@gmail.com> wrote:

Hi,

I had a similar issue, and it is probably a bug:

With the SDL2 port to Emscripten, most SDL_GL_SetAttribute(SDL_GL_CONTEXT_FLAGS*) calls after SDL_GL_CONTEXT_PROFILE_MASK and MAJOR/MINOR will make things fail...

So you need to remove SDL_GL_CONTEXT_FLAGS call, and probably the SDL_GL_FRAMEBUFFER_SRGB_CAPABLE (or put it before the calls to PROFILE_MASK/MAJOR/MINOR)

Thank you. I removed them for Emscripten builds. WebGL doesn’t support SRGB drawing buffers anyway so removal is no loss. But I may try again with a different order so my code will be the same across platforms.

Regards

    -Mark

[キャロウ マーク]

On Jul 22, 2019, at 22:22, Gabriel Cuvillier <gabriel....@gmail.com> wrote:

(or put it before the calls to PROFILE_MASK/MAJOR/MINOR)

This doesn’t help. I had to remove them.