/*

 *  Simple DirectMedia Layer

 *  Copyright (C) 1997-2017 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 SDL_VIDEO_OPENGL_EGL

#if SDL_VIDEO_DRIVER_WINDOWS || SDL_VIDEO_DRIVER_WINRT

#include "../core/windows/SDL_windows.h"

#endif

#if SDL_VIDEO_DRIVER_ANDROID

#include <android/native_window.h>

#endif

#include "SDL_sysvideo.h"

#include "SDL_log.h"

#include "SDL_egl_c.h"

#include "SDL_loadso.h"

#include "SDL_hints.h"

#ifdef EGL_KHR_create_context

/* EGL_OPENGL_ES3_BIT_KHR was added in version 13 of the extension. */

#ifndef EGL_OPENGL_ES3_BIT_KHR

#define EGL_OPENGL_ES3_BIT_KHR 0x00000040

#endif

#endif /* EGL_KHR_create_context */

#if SDL_VIDEO_DRIVER_RPI

/* Raspbian places the OpenGL ES/EGL binaries in a non standard path */

#define DEFAULT_EGL ( vc4 ? "libEGL.so.1" : "/opt/vc/lib/libbrcmEGL.so" )

#define DEFAULT_OGL_ES2 ( vc4 ? "libGLESv2.so.2" : "/opt/vc/lib/libbrcmGLESv2.so" )

#define ALT_EGL "/opt/vc/lib/libEGL.so"

#define ALT_OGL_ES2 "/opt/vc/lib/libGLESv2.so"

#define DEFAULT_OGL_ES_PVR ( vc4 ? "libGLES_CM.so.1" : "/opt/vc/lib/libbrcmGLESv2.so" )

#define DEFAULT_OGL_ES ( vc4 ? "libGLESv1_CM.so.1" : "/opt/vc/lib/libbrcmGLESv2.so" )

#elif SDL_VIDEO_DRIVER_ANDROID || SDL_VIDEO_DRIVER_VIVANTE

/* Android */

#define DEFAULT_EGL "libEGL.so"

#define DEFAULT_OGL_ES2 "libGLESv2.so"

#define DEFAULT_OGL_ES_PVR "libGLES_CM.so"

#define DEFAULT_OGL_ES "libGLESv1_CM.so"

#elif SDL_VIDEO_DRIVER_WINDOWS || SDL_VIDEO_DRIVER_WINRT

/* EGL AND OpenGL ES support via ANGLE */

#define DEFAULT_EGL "libEGL.dll"

#define DEFAULT_OGL_ES2 "libGLESv2.dll"

#define DEFAULT_OGL_ES_PVR "libGLES_CM.dll"

#define DEFAULT_OGL_ES "libGLESv1_CM.dll"

#else

/* Desktop Linux */

#define DEFAULT_OGL "libGL.so.1"

#define DEFAULT_EGL "libEGL.so.1"

#define DEFAULT_OGL_ES2 "libGLESv2.so.2"

#define DEFAULT_OGL_ES_PVR "libGLES_CM.so.1"

#define DEFAULT_OGL_ES "libGLESv1_CM.so.1"

#endif /* SDL_VIDEO_DRIVER_RPI */

#ifdef SDL_VIDEO_STATIC_ANGLE

#define LOAD_FUNC(NAME) \

_this->egl_data->NAME = (void *)NAME;

#else

#define LOAD_FUNC(NAME) \

_this->egl_data->NAME = SDL_LoadFunction(_this->egl_data->dll_handle, #NAME); \

if (!_this->egl_data->NAME) \

{ \

    return SDL_SetError("Could not retrieve EGL function " #NAME); \

}

#endif

static const char * SDL_EGL_GetErrorName(EGLint eglErrorCode)

{

#define SDL_EGL_ERROR_TRANSLATE(e) case e: return #e;

    switch (eglErrorCode) {

        SDL_EGL_ERROR_TRANSLATE(EGL_SUCCESS);

        SDL_EGL_ERROR_TRANSLATE(EGL_NOT_INITIALIZED);

        SDL_EGL_ERROR_TRANSLATE(EGL_BAD_ACCESS);

        SDL_EGL_ERROR_TRANSLATE(EGL_BAD_ALLOC);

        SDL_EGL_ERROR_TRANSLATE(EGL_BAD_ATTRIBUTE);

        SDL_EGL_ERROR_TRANSLATE(EGL_BAD_CONTEXT);

        SDL_EGL_ERROR_TRANSLATE(EGL_BAD_CONFIG);

        SDL_EGL_ERROR_TRANSLATE(EGL_BAD_CURRENT_SURFACE);

        SDL_EGL_ERROR_TRANSLATE(EGL_BAD_DISPLAY);

        SDL_EGL_ERROR_TRANSLATE(EGL_BAD_SURFACE);

        SDL_EGL_ERROR_TRANSLATE(EGL_BAD_MATCH);

        SDL_EGL_ERROR_TRANSLATE(EGL_BAD_PARAMETER);

        SDL_EGL_ERROR_TRANSLATE(EGL_BAD_NATIVE_PIXMAP);

        SDL_EGL_ERROR_TRANSLATE(EGL_BAD_NATIVE_WINDOW);

        SDL_EGL_ERROR_TRANSLATE(EGL_CONTEXT_LOST);

    }

    return "";

}

int SDL_EGL_SetErrorEx(const char * message, const char * eglFunctionName, EGLint eglErrorCode)

{

    const char * errorText = SDL_EGL_GetErrorName(eglErrorCode);

    char altErrorText[32];

    if (errorText[0] == '\0') {

        /* An unknown-to-SDL error code was reported.  Report its hexadecimal value, instead of its name. */

        SDL_snprintf(altErrorText, SDL_arraysize(altErrorText), "0x%x", (unsigned int)eglErrorCode);

        errorText = altErrorText;

    }

    return SDL_SetError("%s (call to %s failed, reporting an error of %s)", message, eglFunctionName, errorText);

}

/* EGL implementation of SDL OpenGL ES support */

typedef enum {

    SDL_EGL_DISPLAY_EXTENSION,

    SDL_EGL_CLIENT_EXTENSION

} SDL_EGL_ExtensionType;

static SDL_bool SDL_EGL_HasExtension(_THIS, SDL_EGL_ExtensionType type, const char *ext)

{

    size_t ext_len;

    const char *ext_override;

    const char *egl_extstr;

    const char *ext_start;

    /* Invalid extensions can be rejected early */

    if (ext == NULL || *ext == 0 || SDL_strchr(ext, ' ') != NULL) {

        /* SDL_LogDebug(SDL_LOG_CATEGORY_VIDEO, "SDL_EGL_HasExtension: Invalid EGL extension"); */

        return SDL_FALSE;

    }

    /* Extensions can be masked with an environment variable.

     * Unlike the OpenGL override, this will use the set bits of an integer

     * to disable the extension.

     *  Bit   Action

     *  0     If set, the display extension is masked and not present to SDL.

     *  1     If set, the client extension is masked and not present to SDL.

     */

    ext_override = SDL_getenv(ext);

    if (ext_override != NULL) {

        int disable_ext = SDL_atoi(ext_override);

        if (disable_ext & 0x01 && type == SDL_EGL_DISPLAY_EXTENSION) {

            return SDL_FALSE;

        } else if (disable_ext & 0x02 && type == SDL_EGL_CLIENT_EXTENSION) {

            return SDL_FALSE;

        }

    }

    ext_len = SDL_strlen(ext);

    switch (type) {

    case SDL_EGL_DISPLAY_EXTENSION:

        egl_extstr = _this->egl_data->eglQueryString(_this->egl_data->egl_display, EGL_EXTENSIONS);

        break;

    case SDL_EGL_CLIENT_EXTENSION:

        /* EGL_EXT_client_extensions modifies eglQueryString to return client extensions

         * if EGL_NO_DISPLAY is passed. Implementations without it are required to return NULL.

         * This behavior is included in EGL 1.5.

         */

        egl_extstr = _this->egl_data->eglQueryString(EGL_NO_DISPLAY, EGL_EXTENSIONS);

        break;

    default:

        /* SDL_LogDebug(SDL_LOG_CATEGORY_VIDEO, "SDL_EGL_HasExtension: Invalid extension type"); */

        return SDL_FALSE;

    }

    if (egl_extstr != NULL) {

        ext_start = egl_extstr;

        while (*ext_start) {

            ext_start = SDL_strstr(ext_start, ext);

            if (ext_start == NULL) {

                return SDL_FALSE;

            }

            /* Check if the match is not just a substring of one of the extensions */

            if (ext_start == egl_extstr || *(ext_start - 1) == ' ') {

                if (ext_start[ext_len] == ' ' || ext_start[ext_len] == 0) {

                    return SDL_TRUE;

                }

            }

            /* If the search stopped in the middle of an extension, skip to the end of it */

            ext_start += ext_len;

            while (*ext_start != ' ' && *ext_start != 0) {

                ext_start++;

            }

        }

    }

    return SDL_FALSE;

}

void *

SDL_EGL_GetProcAddress(_THIS, const char *proc)

{

    static char procname[1024];

    void *retval;

    /* eglGetProcAddress is busted on Android http://code.google.com/p/android/issues/detail?id=7681 */

#if !defined(SDL_VIDEO_DRIVER_ANDROID)

    if (_this->egl_data->eglGetProcAddress) {

        retval = _this->egl_data->eglGetProcAddress(proc);

        if (retval) {

            return retval;

        }

    }

#endif

    retval = SDL_LoadFunction(_this->egl_data->egl_dll_handle, proc);

    if (!retval && SDL_strlen(proc) <= 1022) {

        procname[0] = '_';

        SDL_strlcpy(procname + 1, proc, 1022);

        retval = SDL_LoadFunction(_this->egl_data->egl_dll_handle, procname);

    }

    return retval;

}

void

SDL_EGL_UnloadLibrary(_THIS)

{

    if (_this->egl_data) {

        if (_this->egl_data->egl_display) {

            _this->egl_data->eglTerminate(_this->egl_data->egl_display);

            _this->egl_data->egl_display = NULL;

        }

        if (_this->egl_data->dll_handle) {

            SDL_UnloadObject(_this->egl_data->dll_handle);

            _this->egl_data->dll_handle = NULL;

        }

        if (_this->egl_data->egl_dll_handle) {

            SDL_UnloadObject(_this->egl_data->egl_dll_handle);

            _this->egl_data->egl_dll_handle = NULL;

        }

        SDL_free(_this->egl_data);

        _this->egl_data = NULL;

    }

}

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 SDL_VIDEO_DRIVER_RPI

    SDL_bool vc4 = (0 == access("/sys/module/vc4/", F_OK));

#endif

    if (_this->egl_data) {

        return SDL_SetError("EGL 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 && !vc4) {

                    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 ALT_OGL_ES2

                if (egl_dll_handle == NULL && !vc4) {

                    path = ALT_OGL_ES2;

                    egl_dll_handle = SDL_LoadObject(path);

                }

#endif

            }

        }

#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 && !vc4) {

            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(eglCreatePBufferSurface);

    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;

}

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);

    }

    if (_this->egl_data->egl_surfacetype) {

        attribs[i++] = EGL_SURFACE_TYPE;

        attribs[i++] = _this->egl_data->egl_surfacetype;

    }

    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;

}

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, 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;

}

int

SDL_EGL_MakeCurrent(_THIS, EGLSurface egl_surface, SDL_GLContext context)

{

    EGLContext egl_context = (EGLContext) context;

    if (!_this->egl_data) {

        return SDL_SetError("OpenGL not initialized");

    }

    /* The android emulator crashes badly if you try to eglMakeCurrent 

     * with a valid context and invalid surface, so we have to check for both here.

     */

    if (!egl_context || !egl_surface) {

         _this->egl_data->eglMakeCurrent(_this->egl_data->egl_display, EGL_NO_SURFACE, EGL_NO_SURFACE, EGL_NO_CONTEXT);

    } else {

        if (!_this->egl_data->eglMakeCurrent(_this->egl_data->egl_display,

            egl_surface, egl_surface, egl_context)) {

            return SDL_EGL_SetError("Unable to make EGL context current", "eglMakeCurrent");

        }

    }

    return 0;

}

int

SDL_EGL_SetSwapInterval(_THIS, int interval)

{

    EGLBoolean status;

    if (!_this->egl_data) {

        return SDL_SetError("EGL not initialized");

    }

    status = _this->egl_data->eglSwapInterval(_this->egl_data->egl_display, interval);

    if (status == EGL_TRUE) {

        _this->egl_data->egl_swapinterval = interval;

        return 0;

    }

    return SDL_EGL_SetError("Unable to set the EGL swap interval", "eglSwapInterval");

}

int

SDL_EGL_GetSwapInterval(_THIS)

{

    if (!_this->egl_data) {

        SDL_SetError("EGL not initialized");

        return 0;

    }

    return _this->egl_data->egl_swapinterval;

}

int

SDL_EGL_SwapBuffers(_THIS, EGLSurface egl_surface)

{

    if (!_this->egl_data->eglSwapBuffers(_this->egl_data->egl_display, egl_surface)) {

        return SDL_EGL_SetError("unable to show color buffer in an OS-native window", "eglSwapBuffers");

    }

    return 0;

}

void

SDL_EGL_DeleteContext(_THIS, SDL_GLContext context)

{

    EGLContext egl_context = (EGLContext) context;

    /* Clean up GLES and EGL */

    if (!_this->egl_data) {

        return;

    }

    if (egl_context != NULL && egl_context != EGL_NO_CONTEXT) {

        SDL_EGL_MakeCurrent(_this, NULL, NULL);

        _this->egl_data->eglDestroyContext(_this->egl_data->egl_display, egl_context);

    }

}

EGLSurface *

SDL_EGL_CreateSurface(_THIS, NativeWindowType nw) 

{

    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);

    }

#endif    

    surface = _this->egl_data->eglCreateWindowSurface(

            _this->egl_data->egl_display,

            _this->egl_data->egl_config,

            nw, NULL);

    if (surface == EGL_NO_SURFACE) {

        SDL_EGL_SetError("unable to create an EGL window surface", "eglCreateWindowSurface");

    }

    return surface;

}

void

SDL_EGL_DestroySurface(_THIS, EGLSurface egl_surface) 

{

    if (!_this->egl_data) {

        return;

    }

    if (egl_surface != EGL_NO_SURFACE) {

        _this->egl_data->eglDestroySurface(_this->egl_data->egl_display, egl_surface);

    }

}

#endif /* SDL_VIDEO_OPENGL_EGL */

/* vi: set ts=4 sw=4 expandtab: */