SDL/src/video/windows/SDL_windowsopengles.c

/*
  Simple DirectMedia Layer
  Copyright (C) 1997-2026 Sam Lantinga <slouken@libsdl.org>

  This software is provided 'as-is', without any express or implied
  warranty.  In no event will the authors be held liable for any damages
  arising from the use of this software.

  Permission is granted to anyone to use this software for any purpose,
  including commercial applications, and to alter it and redistribute it
  freely, subject to the following restrictions:

  1. The origin of this software must not be misrepresented; you must not
     claim that you wrote the original software. If you use this software
     in a product, an acknowledgment in the product documentation would be
     appreciated but is not required.
  2. Altered source versions must be plainly marked as such, and must not be
     misrepresented as being the original software.
  3. This notice may not be removed or altered from any source distribution.
*/
#include "SDL_internal.h"

#if defined(SDL_VIDEO_DRIVER_WINDOWS) && defined(SDL_VIDEO_OPENGL_EGL) && !defined(SDL_PLATFORM_XBOXONE) && !defined(SDL_PLATFORM_XBOXSERIES)

#include "SDL_windowsvideo.h"
#include "SDL_windowsopengles.h"
#include "SDL_windowsopengl.h"
#include "SDL_windowswindow.h"

// EGL implementation of SDL OpenGL support

bool WIN_GLES_LoadLibrary(SDL_VideoDevice *_this, const char *path)
{

    // If the profile requested is not GL ES, switch over to WIN_GL functions
    if (_this->gl_config.profile_mask != SDL_GL_CONTEXT_PROFILE_ES &&
        !SDL_GetHintBoolean(SDL_HINT_VIDEO_FORCE_EGL, false)) {
#ifdef SDL_VIDEO_OPENGL_WGL
        WIN_GLES_UnloadLibrary(_this);
        _this->GL_LoadLibrary = WIN_GL_LoadLibrary;
        _this->GL_GetProcAddress = WIN_GL_GetProcAddress;
        _this->GL_UnloadLibrary = WIN_GL_UnloadLibrary;
        _this->GL_CreateContext = WIN_GL_CreateContext;
        _this->GL_MakeCurrent = WIN_GL_MakeCurrent;
        _this->GL_SetSwapInterval = WIN_GL_SetSwapInterval;
        _this->GL_GetSwapInterval = WIN_GL_GetSwapInterval;
        _this->GL_SwapWindow = WIN_GL_SwapWindow;
        _this->GL_DestroyContext = WIN_GL_DestroyContext;
        _this->GL_GetEGLSurface = NULL;
        return WIN_GL_LoadLibrary(_this, path);
#else
        return SDL_SetError("SDL not configured with OpenGL/WGL support");
#endif
    }

    if (!_this->egl_data) {
        return SDL_EGL_LoadLibrary(_this, NULL, EGL_DEFAULT_DISPLAY);
    }

    return true;
}

SDL_GLContext WIN_GLES_CreateContext(SDL_VideoDevice *_this, SDL_Window *window)
{
    SDL_GLContext context;
    SDL_WindowData *data = window->internal;

#ifdef SDL_VIDEO_OPENGL_WGL
    if (_this->gl_config.profile_mask != SDL_GL_CONTEXT_PROFILE_ES &&
        !SDL_GetHintBoolean(SDL_HINT_VIDEO_FORCE_EGL, false)) {
        // Switch to WGL based functions
        WIN_GLES_UnloadLibrary(_this);
        _this->GL_LoadLibrary = WIN_GL_LoadLibrary;
        _this->GL_GetProcAddress = WIN_GL_GetProcAddress;
        _this->GL_UnloadLibrary = WIN_GL_UnloadLibrary;
        _this->GL_CreateContext = WIN_GL_CreateContext;
        _this->GL_MakeCurrent = WIN_GL_MakeCurrent;
        _this->GL_SetSwapInterval = WIN_GL_SetSwapInterval;
        _this->GL_GetSwapInterval = WIN_GL_GetSwapInterval;
        _this->GL_SwapWindow = WIN_GL_SwapWindow;
        _this->GL_DestroyContext = WIN_GL_DestroyContext;
        _this->GL_GetEGLSurface = NULL;

        if (!WIN_GL_LoadLibrary(_this, NULL)) {
            return NULL;
        }

        return WIN_GL_CreateContext(_this, window);
    }
#endif

    context = SDL_EGL_CreateContext(_this, data->egl_surface);
    return context;
}

bool WIN_GLES_DestroyContext(SDL_VideoDevice *_this, SDL_GLContext context)
{
    return SDL_EGL_DestroyContext(_this, context);
}

/* *INDENT-OFF* */ // clang-format off
SDL_EGL_SwapWindow_impl(WIN)
SDL_EGL_MakeCurrent_impl(WIN)
/* *INDENT-ON* */ // clang-format on

bool WIN_GLES_SetupWindow(SDL_VideoDevice *_this, SDL_Window *window)
{
    // The current context is lost in here; save it and reset it.
    SDL_WindowData *windowdata = window->internal;
    SDL_Window *current_win = SDL_GL_GetCurrentWindow();
    SDL_GLContext current_ctx = SDL_GL_GetCurrentContext();

    if (!_this->egl_data) {
// !!! FIXME: commenting out this assertion is (I think) incorrect; figure out why driver_loaded is wrong for ANGLE instead. --ryan.
#if 0 // When hint SDL_HINT_OPENGL_ES_DRIVER is set to "1" (e.g. for ANGLE support), _this->gl_config.driver_loaded can be 1, while the below lines function.
        SDL_assert(!_this->gl_config.driver_loaded);
#endif
        if (!SDL_EGL_LoadLibrary(_this, NULL, EGL_DEFAULT_DISPLAY)) {
            SDL_EGL_UnloadLibrary(_this);
            return false;
        }
        _this->gl_config.driver_loaded = 1;
    }

    // Create the GLES window surface
    windowdata->egl_surface = SDL_EGL_CreateSurface(_this, window, (NativeWindowType)windowdata->hwnd);

    if (windowdata->egl_surface == EGL_NO_SURFACE) {
        return SDL_SetError("Could not create GLES window surface");
    }

    return WIN_GLES_MakeCurrent(_this, current_win, current_ctx);
}

EGLSurface WIN_GLES_GetEGLSurface(SDL_VideoDevice *_this, SDL_Window *window)
{
    SDL_WindowData *windowdata = window->internal;

    return windowdata->egl_surface;
}

#endif // SDL_VIDEO_DRIVER_WINDOWS && SDL_VIDEO_OPENGL_EGL