EGLSurface * SDL_EGL_CreateSurface(_THIS, NativeWindowType nw) { /* max 2 values plus terminator. */ EGLint attribs[3]; int attr = 0; EGLSurface * surface; if (SDL_EGL_ChooseConfig(_this) != 0) { return EGL_NO_SURFACE; } #if SDL_VIDEO_DRIVER_ANDROID { /* Android docs recommend doing this! * Ref: http://developer.android.com/reference/android/app/NativeActivity.html */ EGLint format; _this->egl_data->eglGetConfigAttrib(_this->egl_data->egl_display, _this->egl_data->egl_config, EGL_NATIVE_VISUAL_ID, &format); ANativeWindow_setBuffersGeometry(nw, 0, 0, format); /* Update SurfaceView holder format. * May triggers a sequence surfaceDestroyed(), surfaceCreated(), surfaceChanged(). */ Android_JNI_SetSurfaceViewFormat(format); } #endif if (_this->gl_config.framebuffer_srgb_capable) { #ifdef EGL_KHR_gl_colorspace if (SDL_EGL_HasExtension(_this, SDL_EGL_DISPLAY_EXTENSION, "EGL_KHR_gl_colorspace")) { attribs[attr++] = EGL_GL_COLORSPACE_KHR; attribs[attr++] = EGL_GL_COLORSPACE_SRGB_KHR; } else #endif { SDL_SetError("EGL implementation does not support sRGB system framebuffers"); return EGL_NO_SURFACE; } } attribs[attr++] = EGL_NONE; surface = _this->egl_data->eglCreateWindowSurface( _this->egl_data->egl_display, _this->egl_data->egl_config, nw, &attribs[0]); if (surface == EGL_NO_SURFACE) { SDL_EGL_SetError("unable to create an EGL window surface", "eglCreateWindowSurface"); } return surface; }
SDL_GLContext SDL_EGL_CreateContext(_THIS, EGLSurface egl_surface) { /* max 14 values plus terminator. */ EGLint attribs[15]; int attr = 0; EGLContext egl_context, share_context = EGL_NO_CONTEXT; EGLint profile_mask = _this->gl_config.profile_mask; EGLint major_version = _this->gl_config.major_version; EGLint minor_version = _this->gl_config.minor_version; SDL_bool profile_es = (profile_mask == SDL_GL_CONTEXT_PROFILE_ES); if (!_this->egl_data) { /* The EGL library wasn't loaded, SDL_GetError() should have info */ return NULL; } if (_this->gl_config.share_with_current_context) { share_context = (EGLContext)SDL_GL_GetCurrentContext(); } /* Set the context version and other attributes. */ if ((major_version < 3 || (minor_version == 0 && profile_es)) && _this->gl_config.flags == 0 && (profile_mask == 0 || profile_es)) { /* Create a context without using EGL_KHR_create_context attribs. * When creating a GLES context without EGL_KHR_create_context we can * only specify the major version. When creating a desktop GL context * we can't specify any version, so we only try in that case when the * version is less than 3.0 (matches SDL's GLX/WGL behavior.) */ if (profile_es) { attribs[attr++] = EGL_CONTEXT_CLIENT_VERSION; attribs[attr++] = SDL_max(major_version, 1); } } else { #ifdef EGL_KHR_create_context /* The Major/minor version, context profiles, and context flags can * only be specified when this extension is available. */ if (SDL_EGL_HasExtension(_this, "EGL_KHR_create_context")) { attribs[attr++] = EGL_CONTEXT_MAJOR_VERSION_KHR; attribs[attr++] = major_version; attribs[attr++] = EGL_CONTEXT_MINOR_VERSION_KHR; attribs[attr++] = minor_version; /* SDL profile bits match EGL profile bits. */ if (profile_mask != 0 && profile_mask != SDL_GL_CONTEXT_PROFILE_ES) { attribs[attr++] = EGL_CONTEXT_OPENGL_PROFILE_MASK_KHR; attribs[attr++] = profile_mask; } /* SDL flags match EGL flags. */ if (_this->gl_config.flags != 0) { attribs[attr++] = EGL_CONTEXT_FLAGS_KHR; attribs[attr++] = _this->gl_config.flags; } } else #endif /* EGL_KHR_create_context */ { SDL_SetError("Could not create EGL context (context attributes are not supported)"); return NULL; } } attribs[attr++] = EGL_NONE; /* Bind the API */ if (profile_es) { _this->egl_data->eglBindAPI(EGL_OPENGL_ES_API); } else { _this->egl_data->eglBindAPI(EGL_OPENGL_API); } egl_context = _this->egl_data->eglCreateContext(_this->egl_data->egl_display, _this->egl_data->egl_config, share_context, attribs); if (egl_context == EGL_NO_CONTEXT) { SDL_SetError("Could not create EGL context"); return NULL; } _this->egl_data->egl_swapinterval = 0; if (SDL_EGL_MakeCurrent(_this, egl_surface, egl_context) < 0) { SDL_EGL_DeleteContext(_this, egl_context); SDL_SetError("Could not make EGL context current"); return NULL; } return (SDL_GLContext) egl_context; }
int SDL_EGL_ChooseConfig(_THIS) { /* 64 seems nice. */ EGLint attribs[64]; EGLint found_configs = 0, value; /* 128 seems even nicer here */ EGLConfig configs[128]; int i, j, best_bitdiff = -1, bitdiff; if (!_this->egl_data) { /* The EGL library wasn't loaded, SDL_GetError() should have info */ return -1; } /* Get a valid EGL configuration */ i = 0; attribs[i++] = EGL_RED_SIZE; attribs[i++] = _this->gl_config.red_size; attribs[i++] = EGL_GREEN_SIZE; attribs[i++] = _this->gl_config.green_size; attribs[i++] = EGL_BLUE_SIZE; attribs[i++] = _this->gl_config.blue_size; if (_this->gl_config.alpha_size) { attribs[i++] = EGL_ALPHA_SIZE; attribs[i++] = _this->gl_config.alpha_size; } if (_this->gl_config.buffer_size) { attribs[i++] = EGL_BUFFER_SIZE; attribs[i++] = _this->gl_config.buffer_size; } attribs[i++] = EGL_DEPTH_SIZE; attribs[i++] = _this->gl_config.depth_size; if (_this->gl_config.stencil_size) { attribs[i++] = EGL_STENCIL_SIZE; attribs[i++] = _this->gl_config.stencil_size; } if (_this->gl_config.multisamplebuffers) { attribs[i++] = EGL_SAMPLE_BUFFERS; attribs[i++] = _this->gl_config.multisamplebuffers; } if (_this->gl_config.multisamplesamples) { attribs[i++] = EGL_SAMPLES; attribs[i++] = _this->gl_config.multisamplesamples; } attribs[i++] = EGL_RENDERABLE_TYPE; if (_this->gl_config.profile_mask == SDL_GL_CONTEXT_PROFILE_ES) { #ifdef EGL_KHR_create_context if (_this->gl_config.major_version >= 3 && SDL_EGL_HasExtension(_this, "EGL_KHR_create_context")) { attribs[i++] = EGL_OPENGL_ES3_BIT_KHR; } else #endif if (_this->gl_config.major_version >= 2) { attribs[i++] = EGL_OPENGL_ES2_BIT; } else { attribs[i++] = EGL_OPENGL_ES_BIT; } _this->egl_data->eglBindAPI(EGL_OPENGL_ES_API); } else { attribs[i++] = EGL_OPENGL_BIT; _this->egl_data->eglBindAPI(EGL_OPENGL_API); } attribs[i++] = EGL_NONE; if (_this->egl_data->eglChooseConfig(_this->egl_data->egl_display, attribs, configs, SDL_arraysize(configs), &found_configs) == EGL_FALSE || found_configs == 0) { return SDL_SetError("Couldn't find matching EGL config"); } /* eglChooseConfig returns a number of configurations that match or exceed the requested attribs. */ /* From those, we select the one that matches our requirements more closely via a makeshift algorithm */ for (i = 0; i < found_configs; i++ ) { bitdiff = 0; for (j = 0; j < SDL_arraysize(attribs) - 1; j += 2) { if (attribs[j] == EGL_NONE) { break; } if ( attribs[j+1] != EGL_DONT_CARE && ( attribs[j] == EGL_RED_SIZE || attribs[j] == EGL_GREEN_SIZE || attribs[j] == EGL_BLUE_SIZE || attribs[j] == EGL_ALPHA_SIZE || attribs[j] == EGL_DEPTH_SIZE || attribs[j] == EGL_STENCIL_SIZE)) { _this->egl_data->eglGetConfigAttrib(_this->egl_data->egl_display, configs[i], attribs[j], &value); bitdiff += value - attribs[j + 1]; /* value is always >= attrib */ } } if (bitdiff < best_bitdiff || best_bitdiff == -1) { _this->egl_data->egl_config = configs[i]; best_bitdiff = bitdiff; } if (bitdiff == 0) { break; /* we found an exact match! */ } } return 0; }
int SDL_EGL_ChooseConfig(_THIS) { /* 64 seems nice. */ EGLint attribs[64]; EGLint found_configs = 0, value; #ifdef SDL_VIDEO_DRIVER_KMSDRM /* Intel EGL on KMS/DRM (al least) returns invalid configs that confuse the bitdiff search used */ /* later in this function, so we simply use the first one when using the KMSDRM driver for now. */ EGLConfig configs[1]; #else /* 128 seems even nicer here */ EGLConfig configs[128]; #endif int i, j, best_bitdiff = -1, bitdiff; if (!_this->egl_data) { /* The EGL library wasn't loaded, SDL_GetError() should have info */ return -1; } /* Get a valid EGL configuration */ i = 0; attribs[i++] = EGL_RED_SIZE; attribs[i++] = _this->gl_config.red_size; attribs[i++] = EGL_GREEN_SIZE; attribs[i++] = _this->gl_config.green_size; attribs[i++] = EGL_BLUE_SIZE; attribs[i++] = _this->gl_config.blue_size; if (_this->gl_config.alpha_size) { attribs[i++] = EGL_ALPHA_SIZE; attribs[i++] = _this->gl_config.alpha_size; } if (_this->gl_config.buffer_size) { attribs[i++] = EGL_BUFFER_SIZE; attribs[i++] = _this->gl_config.buffer_size; } attribs[i++] = EGL_DEPTH_SIZE; attribs[i++] = _this->gl_config.depth_size; if (_this->gl_config.stencil_size) { attribs[i++] = EGL_STENCIL_SIZE; attribs[i++] = _this->gl_config.stencil_size; } if (_this->gl_config.multisamplebuffers) { attribs[i++] = EGL_SAMPLE_BUFFERS; attribs[i++] = _this->gl_config.multisamplebuffers; } if (_this->gl_config.multisamplesamples) { attribs[i++] = EGL_SAMPLES; attribs[i++] = _this->gl_config.multisamplesamples; } if (_this->gl_config.framebuffer_srgb_capable) { #ifdef EGL_KHR_gl_colorspace if (SDL_EGL_HasExtension(_this, SDL_EGL_DISPLAY_EXTENSION, "EGL_KHR_gl_colorspace")) { attribs[i++] = EGL_GL_COLORSPACE_KHR; attribs[i++] = EGL_GL_COLORSPACE_SRGB_KHR; } else #endif { return SDL_SetError("EGL implementation does not support sRGB system framebuffers"); } } attribs[i++] = EGL_RENDERABLE_TYPE; if (_this->gl_config.profile_mask == SDL_GL_CONTEXT_PROFILE_ES) { #ifdef EGL_KHR_create_context if (_this->gl_config.major_version >= 3 && SDL_EGL_HasExtension(_this, SDL_EGL_DISPLAY_EXTENSION, "EGL_KHR_create_context")) { attribs[i++] = EGL_OPENGL_ES3_BIT_KHR; } else #endif if (_this->gl_config.major_version >= 2) { attribs[i++] = EGL_OPENGL_ES2_BIT; } else { attribs[i++] = EGL_OPENGL_ES_BIT; } _this->egl_data->eglBindAPI(EGL_OPENGL_ES_API); } else { attribs[i++] = EGL_OPENGL_BIT; _this->egl_data->eglBindAPI(EGL_OPENGL_API); } attribs[i++] = EGL_NONE; if (_this->egl_data->eglChooseConfig(_this->egl_data->egl_display, attribs, configs, SDL_arraysize(configs), &found_configs) == EGL_FALSE || found_configs == 0) { return SDL_EGL_SetError("Couldn't find matching EGL config", "eglChooseConfig"); } /* eglChooseConfig returns a number of configurations that match or exceed the requested attribs. */ /* From those, we select the one that matches our requirements more closely via a makeshift algorithm */ for (i = 0; i < found_configs; i++ ) { bitdiff = 0; for (j = 0; j < SDL_arraysize(attribs) - 1; j += 2) { if (attribs[j] == EGL_NONE) { break; } if ( attribs[j+1] != EGL_DONT_CARE && ( attribs[j] == EGL_RED_SIZE || attribs[j] == EGL_GREEN_SIZE || attribs[j] == EGL_BLUE_SIZE || attribs[j] == EGL_ALPHA_SIZE || attribs[j] == EGL_DEPTH_SIZE || attribs[j] == EGL_STENCIL_SIZE)) { _this->egl_data->eglGetConfigAttrib(_this->egl_data->egl_display, configs[i], attribs[j], &value); bitdiff += value - attribs[j + 1]; /* value is always >= attrib */ } } if (bitdiff < best_bitdiff || best_bitdiff == -1) { _this->egl_data->egl_config = configs[i]; best_bitdiff = bitdiff; } if (bitdiff == 0) { break; /* we found an exact match! */ } } return 0; }
int SDL_EGL_LoadLibrary(_THIS, const char *egl_path, NativeDisplayType native_display, EGLenum platform) { void *dll_handle = NULL, *egl_dll_handle = NULL; /* The naming is counter intuitive, but hey, I just work here -- Gabriel */ const char *path = NULL; int egl_version_major = 0, egl_version_minor = 0; #if SDL_VIDEO_DRIVER_WINDOWS || SDL_VIDEO_DRIVER_WINRT const char *d3dcompiler; #endif if (_this->egl_data) { return SDL_SetError("OpenGL ES context already created"); } _this->egl_data = (struct SDL_EGL_VideoData *) SDL_calloc(1, sizeof(SDL_EGL_VideoData)); if (!_this->egl_data) { return SDL_OutOfMemory(); } #if SDL_VIDEO_DRIVER_WINDOWS || SDL_VIDEO_DRIVER_WINRT d3dcompiler = SDL_GetHint(SDL_HINT_VIDEO_WIN_D3DCOMPILER); if (!d3dcompiler) { if (WIN_IsWindowsVistaOrGreater()) { d3dcompiler = "d3dcompiler_46.dll"; } else { d3dcompiler = "d3dcompiler_43.dll"; } } if (SDL_strcasecmp(d3dcompiler, "none") != 0) { if (SDL_LoadObject(d3dcompiler) == NULL) { SDL_ClearError(); } } #endif #ifndef SDL_VIDEO_STATIC_ANGLE /* A funny thing, loading EGL.so first does not work on the Raspberry, so we load libGL* first */ path = SDL_getenv("SDL_VIDEO_GL_DRIVER"); if (path != NULL) { egl_dll_handle = SDL_LoadObject(path); } if (egl_dll_handle == NULL) { if (_this->gl_config.profile_mask == SDL_GL_CONTEXT_PROFILE_ES) { if (_this->gl_config.major_version > 1) { path = DEFAULT_OGL_ES2; egl_dll_handle = SDL_LoadObject(path); #ifdef ALT_OGL_ES2 if (egl_dll_handle == NULL) { path = ALT_OGL_ES2; egl_dll_handle = SDL_LoadObject(path); } #endif } else { path = DEFAULT_OGL_ES; egl_dll_handle = SDL_LoadObject(path); if (egl_dll_handle == NULL) { path = DEFAULT_OGL_ES_PVR; egl_dll_handle = SDL_LoadObject(path); } } } #ifdef DEFAULT_OGL else { path = DEFAULT_OGL; egl_dll_handle = SDL_LoadObject(path); } #endif } _this->egl_data->egl_dll_handle = egl_dll_handle; if (egl_dll_handle == NULL) { return SDL_SetError("Could not initialize OpenGL / GLES library"); } /* Loading libGL* in the previous step took care of loading libEGL.so, but we future proof by double checking */ if (egl_path != NULL) { dll_handle = SDL_LoadObject(egl_path); } /* Try loading a EGL symbol, if it does not work try the default library paths */ if (dll_handle == NULL || SDL_LoadFunction(dll_handle, "eglChooseConfig") == NULL) { if (dll_handle != NULL) { SDL_UnloadObject(dll_handle); } path = SDL_getenv("SDL_VIDEO_EGL_DRIVER"); if (path == NULL) { path = DEFAULT_EGL; } dll_handle = SDL_LoadObject(path); #ifdef ALT_EGL if (dll_handle == NULL) { path = ALT_EGL; dll_handle = SDL_LoadObject(path); } #endif if (dll_handle == NULL || SDL_LoadFunction(dll_handle, "eglChooseConfig") == NULL) { if (dll_handle != NULL) { SDL_UnloadObject(dll_handle); } return SDL_SetError("Could not load EGL library"); } SDL_ClearError(); } #endif _this->egl_data->dll_handle = dll_handle; /* Load new function pointers */ LOAD_FUNC(eglGetDisplay); LOAD_FUNC(eglInitialize); LOAD_FUNC(eglTerminate); LOAD_FUNC(eglGetProcAddress); LOAD_FUNC(eglChooseConfig); LOAD_FUNC(eglGetConfigAttrib); LOAD_FUNC(eglCreateContext); LOAD_FUNC(eglDestroyContext); LOAD_FUNC(eglCreateWindowSurface); LOAD_FUNC(eglDestroySurface); LOAD_FUNC(eglMakeCurrent); LOAD_FUNC(eglSwapBuffers); LOAD_FUNC(eglSwapInterval); LOAD_FUNC(eglWaitNative); LOAD_FUNC(eglWaitGL); LOAD_FUNC(eglBindAPI); LOAD_FUNC(eglQueryString); LOAD_FUNC(eglGetError); if (_this->egl_data->eglQueryString) { /* EGL 1.5 allows querying for client version */ const char *egl_version = _this->egl_data->eglQueryString(EGL_NO_DISPLAY, EGL_VERSION); if (egl_version != NULL) { if (SDL_sscanf(egl_version, "%d.%d", &egl_version_major, &egl_version_minor) != 2) { egl_version_major = 0; egl_version_minor = 0; SDL_LogWarn(SDL_LOG_CATEGORY_VIDEO, "Could not parse EGL version string: %s", egl_version); } } } if (egl_version_major == 1 && egl_version_minor == 5) { LOAD_FUNC(eglGetPlatformDisplay); } _this->egl_data->egl_display = EGL_NO_DISPLAY; #if !defined(__WINRT__) if (platform) { if (egl_version_major == 1 && egl_version_minor == 5) { _this->egl_data->egl_display = _this->egl_data->eglGetPlatformDisplay(platform, (void *)(size_t)native_display, NULL); } else { if (SDL_EGL_HasExtension(_this, SDL_EGL_CLIENT_EXTENSION, "EGL_EXT_platform_base")) { _this->egl_data->eglGetPlatformDisplayEXT = SDL_EGL_GetProcAddress(_this, "eglGetPlatformDisplayEXT"); if (_this->egl_data->eglGetPlatformDisplayEXT) { _this->egl_data->egl_display = _this->egl_data->eglGetPlatformDisplayEXT(platform, (void *)(size_t)native_display, NULL); } } } } /* Try the implementation-specific eglGetDisplay even if eglGetPlatformDisplay fails */ if (_this->egl_data->egl_display == EGL_NO_DISPLAY) { _this->egl_data->egl_display = _this->egl_data->eglGetDisplay(native_display); } if (_this->egl_data->egl_display == EGL_NO_DISPLAY) { return SDL_SetError("Could not get EGL display"); } if (_this->egl_data->eglInitialize(_this->egl_data->egl_display, NULL, NULL) != EGL_TRUE) { return SDL_SetError("Could not initialize EGL"); } #endif if (path) { SDL_strlcpy(_this->gl_config.driver_path, path, sizeof(_this->gl_config.driver_path) - 1); } else { *_this->gl_config.driver_path = '\0'; } return 0; }
SDL_GLContext SDL_EGL_CreateContext(_THIS, EGLSurface egl_surface) { /* max 14 values plus terminator. */ EGLint attribs[15]; int attr = 0; EGLContext egl_context, share_context = EGL_NO_CONTEXT; EGLint profile_mask = _this->gl_config.profile_mask; EGLint major_version = _this->gl_config.major_version; EGLint minor_version = _this->gl_config.minor_version; SDL_bool profile_es = (profile_mask == SDL_GL_CONTEXT_PROFILE_ES); if (!_this->egl_data) { /* The EGL library wasn't loaded, SDL_GetError() should have info */ return NULL; } if (_this->gl_config.share_with_current_context) { share_context = (EGLContext)SDL_GL_GetCurrentContext(); } #if SDL_VIDEO_DRIVER_ANDROID if ((_this->gl_config.flags & SDL_GL_CONTEXT_DEBUG_FLAG) != 0) { /* If SDL_GL_CONTEXT_DEBUG_FLAG is set but EGL_KHR_debug unsupported, unset. * This is required because some Android devices like to complain about it * by "silently" failing, logging a hint which could be easily overlooked: * E/libEGL (26984): validate_display:255 error 3008 (EGL_BAD_DISPLAY) * The following explicitly checks for EGL_KHR_debug before EGL 1.5 */ int egl_version_major = _this->egl_data->egl_version_major; int egl_version_minor = _this->egl_data->egl_version_minor; if (((egl_version_major < 1) || (egl_version_major == 1 && egl_version_minor < 5)) && !SDL_EGL_HasExtension(_this, SDL_EGL_DISPLAY_EXTENSION, "EGL_KHR_debug")) { /* SDL profile bits match EGL profile bits. */ _this->gl_config.flags &= ~SDL_GL_CONTEXT_DEBUG_FLAG; } } #endif /* Set the context version and other attributes. */ if ((major_version < 3 || (minor_version == 0 && profile_es)) && _this->gl_config.flags == 0 && (profile_mask == 0 || profile_es)) { /* Create a context without using EGL_KHR_create_context attribs. * When creating a GLES context without EGL_KHR_create_context we can * only specify the major version. When creating a desktop GL context * we can't specify any version, so we only try in that case when the * version is less than 3.0 (matches SDL's GLX/WGL behavior.) */ if (profile_es) { attribs[attr++] = EGL_CONTEXT_CLIENT_VERSION; attribs[attr++] = SDL_max(major_version, 1); } } else { #ifdef EGL_KHR_create_context /* The Major/minor version, context profiles, and context flags can * only be specified when this extension is available. */ if (SDL_EGL_HasExtension(_this, SDL_EGL_DISPLAY_EXTENSION, "EGL_KHR_create_context")) { attribs[attr++] = EGL_CONTEXT_MAJOR_VERSION_KHR; attribs[attr++] = major_version; attribs[attr++] = EGL_CONTEXT_MINOR_VERSION_KHR; attribs[attr++] = minor_version; /* SDL profile bits match EGL profile bits. */ if (profile_mask != 0 && profile_mask != SDL_GL_CONTEXT_PROFILE_ES) { attribs[attr++] = EGL_CONTEXT_OPENGL_PROFILE_MASK_KHR; attribs[attr++] = profile_mask; } /* SDL flags match EGL flags. */ if (_this->gl_config.flags != 0) { attribs[attr++] = EGL_CONTEXT_FLAGS_KHR; attribs[attr++] = _this->gl_config.flags; } } else #endif /* EGL_KHR_create_context */ { SDL_SetError("Could not create EGL context (context attributes are not supported)"); return NULL; } } if (_this->gl_config.no_error) { #ifdef EGL_KHR_create_context_no_error if (SDL_EGL_HasExtension(_this, SDL_EGL_DISPLAY_EXTENSION, "EGL_KHR_create_context_no_error")) { attribs[attr++] = EGL_CONTEXT_OPENGL_NO_ERROR_KHR; attribs[attr++] = _this->gl_config.no_error; } else #endif { SDL_SetError("EGL implementation does not support no_error contexts"); return NULL; } } attribs[attr++] = EGL_NONE; /* Bind the API */ if (profile_es) { _this->egl_data->eglBindAPI(EGL_OPENGL_ES_API); } else { _this->egl_data->eglBindAPI(EGL_OPENGL_API); } egl_context = _this->egl_data->eglCreateContext(_this->egl_data->egl_display, _this->egl_data->egl_config, share_context, attribs); if (egl_context == EGL_NO_CONTEXT) { SDL_EGL_SetError("Could not create EGL context", "eglCreateContext"); return NULL; } _this->egl_data->egl_swapinterval = 0; if (SDL_EGL_MakeCurrent(_this, egl_surface, egl_context) < 0) { /* Save the SDL error set by SDL_EGL_MakeCurrent */ char errorText[1024]; SDL_strlcpy(errorText, SDL_GetError(), SDL_arraysize(errorText)); /* Delete the context, which may alter the value returned by SDL_GetError() */ SDL_EGL_DeleteContext(_this, egl_context); /* Restore the SDL error */ SDL_SetError("%s", errorText); return NULL; } return (SDL_GLContext) egl_context; }