/*

  Simple DirectMedia Layer

  Copyright (C) 1997-2014 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_DRIVER_X11

#include "SDL_x11video.h"

#include "SDL_assert.h"

/* GLX implementation of SDL OpenGL support */

#if SDL_VIDEO_OPENGL_GLX

#include "SDL_loadso.h"

#include "SDL_x11opengles.h"

#if defined(__IRIX__)

/* IRIX doesn't have a GL library versioning system */

#define DEFAULT_OPENGL  "libGL.so"

#elif defined(__MACOSX__)

#define DEFAULT_OPENGL  "/usr/X11R6/lib/libGL.1.dylib"

#elif defined(__QNXNTO__)

#define DEFAULT_OPENGL  "libGL.so.3"

#else

#define DEFAULT_OPENGL  "libGL.so.1"

#endif

#ifndef GLX_NONE_EXT

#define GLX_NONE_EXT                       0x8000

#endif

#ifndef GLX_ARB_multisample

#define GLX_ARB_multisample

#define GLX_SAMPLE_BUFFERS_ARB             100000

#define GLX_SAMPLES_ARB                    100001

#endif

#ifndef GLX_EXT_visual_rating

#define GLX_EXT_visual_rating

#define GLX_VISUAL_CAVEAT_EXT              0x20

#define GLX_NONE_EXT                       0x8000

#define GLX_SLOW_VISUAL_EXT                0x8001

#define GLX_NON_CONFORMANT_VISUAL_EXT      0x800D

#endif

#ifndef GLX_EXT_visual_info

#define GLX_EXT_visual_info

#define GLX_X_VISUAL_TYPE_EXT              0x22

#define GLX_DIRECT_COLOR_EXT               0x8003

#endif

#ifndef GLX_ARB_create_context

#define GLX_ARB_create_context

#define GLX_CONTEXT_MAJOR_VERSION_ARB      0x2091

#define GLX_CONTEXT_MINOR_VERSION_ARB      0x2092

#define GLX_CONTEXT_FLAGS_ARB              0x2094

#define GLX_CONTEXT_DEBUG_BIT_ARB          0x0001

#define GLX_CONTEXT_FORWARD_COMPATIBLE_BIT_ARB 0x0002

/* Typedef for the GL 3.0 context creation function */

typedef GLXContext(*PFNGLXCREATECONTEXTATTRIBSARBPROC) (Display * dpy,

                                                        GLXFBConfig config,

                                                        GLXContext

                                                        share_context,

                                                        Bool direct,

                                                        const int

                                                        *attrib_list);

#endif

#ifndef GLX_ARB_create_context_profile

#define GLX_ARB_create_context_profile

#define GLX_CONTEXT_PROFILE_MASK_ARB       0x9126

#define GLX_CONTEXT_CORE_PROFILE_BIT_ARB   0x00000001

#define GLX_CONTEXT_COMPATIBILITY_PROFILE_BIT_ARB 0x00000002

#endif

#ifndef GLX_ARB_create_context_robustness

#define GLX_ARB_create_context_robustness

#define GLX_CONTEXT_ROBUST_ACCESS_BIT_ARB  0x00000004

#define GLX_CONTEXT_RESET_NOTIFICATION_STRATEGY_ARB     0x8256

#define GLX_NO_RESET_NOTIFICATION_ARB                   0x8261

#define GLX_LOSE_CONTEXT_ON_RESET_ARB                   0x8252

#endif

#ifndef GLX_EXT_create_context_es2_profile

#define GLX_EXT_create_context_es2_profile

#ifndef GLX_CONTEXT_ES2_PROFILE_BIT_EXT

#define GLX_CONTEXT_ES2_PROFILE_BIT_EXT    0x00000002

#endif

#endif

#ifndef GLX_ARB_framebuffer_sRGB

#define GLX_ARB_framebuffer_sRGB

#ifndef GLX_FRAMEBUFFER_SRGB_CAPABLE_ARB

#define GLX_FRAMEBUFFER_SRGB_CAPABLE_ARB                0x20B2

#endif

#endif

#ifndef GLX_EXT_swap_control

#define GLX_SWAP_INTERVAL_EXT              0x20F1

#define GLX_MAX_SWAP_INTERVAL_EXT          0x20F2

#endif

#ifndef GLX_EXT_swap_control_tear

#define GLX_LATE_SWAPS_TEAR_EXT 0x20F3

#endif

#define OPENGL_REQUIRES_DLOPEN

#if defined(OPENGL_REQUIRES_DLOPEN) && defined(SDL_LOADSO_DLOPEN)

#include <dlfcn.h>

#define GL_LoadObject(X)    dlopen(X, (RTLD_NOW|RTLD_GLOBAL))

#define GL_LoadFunction     dlsym

#define GL_UnloadObject     dlclose

#else

#define GL_LoadObject   SDL_LoadObject

#define GL_LoadFunction SDL_LoadFunction

#define GL_UnloadObject SDL_UnloadObject

#endif

static void X11_GL_InitExtensions(_THIS);

int

X11_GL_LoadLibrary(_THIS, const char *path)

{

    Display *display;

    void *handle;

    if (_this->gl_data) {

        return SDL_SetError("OpenGL context already created");

    }

    /* Load the OpenGL library */

    if (path == NULL) {

        path = SDL_getenv("SDL_OPENGL_LIBRARY");

    }

    if (path == NULL) {

        path = DEFAULT_OPENGL;

    }

    _this->gl_config.dll_handle = GL_LoadObject(path);

    if (!_this->gl_config.dll_handle) {

#if defined(OPENGL_REQUIRES_DLOPEN) && defined(SDL_LOADSO_DLOPEN)

        SDL_SetError("Failed loading %s: %s", path, dlerror());

#endif

        return -1;

    }

    SDL_strlcpy(_this->gl_config.driver_path, path,

                SDL_arraysize(_this->gl_config.driver_path));

    /* Allocate OpenGL memory */

    _this->gl_data =

        (struct SDL_GLDriverData *) SDL_calloc(1,

                                               sizeof(struct

                                                      SDL_GLDriverData));

    if (!_this->gl_data) {

        return SDL_OutOfMemory();

    }

    /* Load function pointers */

    handle = _this->gl_config.dll_handle;

    _this->gl_data->glXQueryExtension =

        (Bool (*)(Display *, int *, int *))

            GL_LoadFunction(handle, "glXQueryExtension");

    _this->gl_data->glXGetProcAddress =

        (void *(*)(const GLubyte *))

            GL_LoadFunction(handle, "glXGetProcAddressARB");

    _this->gl_data->glXChooseVisual =

        (XVisualInfo * (*)(Display *, int, int *))

            X11_GL_GetProcAddress(_this, "glXChooseVisual");

    _this->gl_data->glXCreateContext =

        (GLXContext(*)(Display *, XVisualInfo *, GLXContext, int))

            X11_GL_GetProcAddress(_this, "glXCreateContext");

    _this->gl_data->glXDestroyContext =

        (void (*)(Display *, GLXContext))

            X11_GL_GetProcAddress(_this, "glXDestroyContext");

    _this->gl_data->glXMakeCurrent =

        (int (*)(Display *, GLXDrawable, GLXContext))

            X11_GL_GetProcAddress(_this, "glXMakeCurrent");

    _this->gl_data->glXSwapBuffers =

        (void (*)(Display *, GLXDrawable))

            X11_GL_GetProcAddress(_this, "glXSwapBuffers");

    _this->gl_data->glXQueryDrawable =

        (void (*)(Display*,GLXDrawable,int,unsigned int*))

            X11_GL_GetProcAddress(_this, "glXQueryDrawable");

    if (!_this->gl_data->glXQueryExtension ||

        !_this->gl_data->glXChooseVisual ||

        !_this->gl_data->glXCreateContext ||

        !_this->gl_data->glXDestroyContext ||

        !_this->gl_data->glXMakeCurrent ||

        !_this->gl_data->glXSwapBuffers) {

        return SDL_SetError("Could not retrieve OpenGL functions");

    }

    display = ((SDL_VideoData *) _this->driverdata)->display;

    if (!_this->gl_data->glXQueryExtension(display, &_this->gl_data->errorBase, &_this->gl_data->eventBase)) {

        return SDL_SetError("GLX is not supported");

    }

    /* Initialize extensions */

    X11_GL_InitExtensions(_this);

    /* If we need a GL ES context and there's no  

     * GLX_EXT_create_context_es2_profile extension, switch over to X11_GLES functions  

     */

    if (_this->gl_config.profile_mask == SDL_GL_CONTEXT_PROFILE_ES && 

        ! _this->gl_data->HAS_GLX_EXT_create_context_es2_profile ) {

#if SDL_VIDEO_OPENGL_EGL

        X11_GL_UnloadLibrary(_this);

        /* Better avoid conflicts! */

        if (_this->gl_config.dll_handle != NULL ) {

            GL_UnloadObject(_this->gl_config.dll_handle);

            _this->gl_config.dll_handle = NULL;

        }

        _this->GL_LoadLibrary = X11_GLES_LoadLibrary;

        _this->GL_GetProcAddress = X11_GLES_GetProcAddress;

        _this->GL_UnloadLibrary = X11_GLES_UnloadLibrary;

        _this->GL_CreateContext = X11_GLES_CreateContext;

        _this->GL_MakeCurrent = X11_GLES_MakeCurrent;

        _this->GL_SetSwapInterval = X11_GLES_SetSwapInterval;

        _this->GL_GetSwapInterval = X11_GLES_GetSwapInterval;

        _this->GL_SwapWindow = X11_GLES_SwapWindow;

        _this->GL_DeleteContext = X11_GLES_DeleteContext;

        return X11_GLES_LoadLibrary(_this, NULL);

#else

        return SDL_SetError("SDL not configured with EGL support");

#endif

    }

    return 0;

}

void *

X11_GL_GetProcAddress(_THIS, const char *proc)

{

    if (_this->gl_data->glXGetProcAddress) {

        return _this->gl_data->glXGetProcAddress((const GLubyte *) proc);

    }

    return GL_LoadFunction(_this->gl_config.dll_handle, proc);

}

void

X11_GL_UnloadLibrary(_THIS)

{

    /* Don't actually unload the library, since it may have registered

     * X11 shutdown hooks, per the notes at:

     * http://dri.sourceforge.net/doc/DRIuserguide.html

     */

#if 0

    GL_UnloadObject(_this->gl_config.dll_handle);

    _this->gl_config.dll_handle = NULL;

#endif

    /* Free OpenGL memory */

    SDL_free(_this->gl_data);

    _this->gl_data = NULL;

}

static SDL_bool

HasExtension(const char *extension, const char *extensions)

{

    const char *start;

    const char *where, *terminator;

    /* Extension names should not have spaces. */

    where = SDL_strchr(extension, ' ');

    if (where || *extension == '\0')

        return SDL_FALSE;

    if (!extensions)

        return SDL_FALSE;

    /* It takes a bit of care to be fool-proof about parsing the

     * OpenGL extensions string. Don't be fooled by sub-strings,

     * etc. */

    start = extensions;

    for (;;) {

        where = SDL_strstr(start, extension);

        if (!where)

            break;

        terminator = where + SDL_strlen(extension);

        if (where == start || *(where - 1) == ' ')

            if (*terminator == ' ' || *terminator == '\0')

                return SDL_TRUE;

        start = terminator;

    }

    return SDL_FALSE;

}

static void

X11_GL_InitExtensions(_THIS)

{

    Display *display = ((SDL_VideoData *) _this->driverdata)->display;

    int screen = DefaultScreen(display);

    XVisualInfo *vinfo;

    XSetWindowAttributes xattr;

    Window w;

    GLXContext context;

    const char *(*glXQueryExtensionsStringFunc) (Display *, int);

    const char *extensions;

    vinfo = X11_GL_GetVisual(_this, display, screen);

    if (!vinfo) {

        return;

    }

    xattr.background_pixel = 0;

    xattr.border_pixel = 0;

    xattr.colormap =

        X11_XCreateColormap(display, RootWindow(display, screen), vinfo->visual,

                        AllocNone);

    w = X11_XCreateWindow(display, RootWindow(display, screen), 0, 0, 32, 32, 0,

                      vinfo->depth, InputOutput, vinfo->visual,

                      (CWBackPixel | CWBorderPixel | CWColormap), &xattr);

    context = _this->gl_data->glXCreateContext(display, vinfo, NULL, True);

    if (context) {

        _this->gl_data->glXMakeCurrent(display, w, context);

    }

    X11_XFree(vinfo);

    glXQueryExtensionsStringFunc =

        (const char *(*)(Display *, int)) X11_GL_GetProcAddress(_this,

                                                                "glXQueryExtensionsString");

    if (glXQueryExtensionsStringFunc) {

        extensions = glXQueryExtensionsStringFunc(display, screen);

    } else {

        extensions = NULL;

    }

    /* Check for GLX_EXT_swap_control(_tear) */

    _this->gl_data->HAS_GLX_EXT_swap_control_tear = SDL_FALSE;

    if (HasExtension("GLX_EXT_swap_control", extensions)) {

        _this->gl_data->glXSwapIntervalEXT =

            (void (*)(Display*,GLXDrawable,int))

                X11_GL_GetProcAddress(_this, "glXSwapIntervalEXT");

        if (HasExtension("GLX_EXT_swap_control_tear", extensions)) {

            _this->gl_data->HAS_GLX_EXT_swap_control_tear = SDL_TRUE;

        }

    }

    /* Check for GLX_MESA_swap_control */

    if (HasExtension("GLX_MESA_swap_control", extensions)) {

        _this->gl_data->glXSwapIntervalMESA =

            (int(*)(int)) X11_GL_GetProcAddress(_this, "glXSwapIntervalMESA");

        _this->gl_data->glXGetSwapIntervalMESA =

            (int(*)(void)) X11_GL_GetProcAddress(_this,

                                                   "glXGetSwapIntervalMESA");

    }

    /* Check for GLX_SGI_swap_control */

    if (HasExtension("GLX_SGI_swap_control", extensions)) {

        _this->gl_data->glXSwapIntervalSGI =

            (int (*)(int)) X11_GL_GetProcAddress(_this, "glXSwapIntervalSGI");

    }

    /* Check for GLX_EXT_visual_rating */

    if (HasExtension("GLX_EXT_visual_rating", extensions)) {

        _this->gl_data->HAS_GLX_EXT_visual_rating = SDL_TRUE;

    }

    /* Check for GLX_EXT_visual_info */

    if (HasExtension("GLX_EXT_visual_info", extensions)) {

        _this->gl_data->HAS_GLX_EXT_visual_info = SDL_TRUE;

    }

    /* Check for GLX_EXT_create_context_es2_profile */

    if (HasExtension("GLX_EXT_create_context_es2_profile", extensions)) {

        _this->gl_data->HAS_GLX_EXT_create_context_es2_profile = SDL_TRUE;

    }

    if (context) {

        _this->gl_data->glXMakeCurrent(display, None, NULL);

        _this->gl_data->glXDestroyContext(display, context);

    }

    X11_XDestroyWindow(display, w);

    X11_PumpEvents(_this);

}

/* glXChooseVisual and glXChooseFBConfig have some small differences in

 * the attribute encoding, it can be chosen with the for_FBConfig parameter.

 */

int

X11_GL_GetAttributes(_THIS, Display * display, int screen, int * attribs, int size, Bool for_FBConfig)

{

    int i = 0;

    const int MAX_ATTRIBUTES = 64;

    /* assert buffer is large enough to hold all SDL attributes. */

    SDL_assert(size >= MAX_ATTRIBUTES);

    /* Setup our GLX attributes according to the gl_config. */

    if( for_FBConfig ) {

        attribs[i++] = GLX_RENDER_TYPE;

        attribs[i++] = GLX_RGBA_BIT;

    } else {

        attribs[i++] = GLX_RGBA;

    }

    attribs[i++] = GLX_RED_SIZE;

    attribs[i++] = _this->gl_config.red_size;

    attribs[i++] = GLX_GREEN_SIZE;

    attribs[i++] = _this->gl_config.green_size;

    attribs[i++] = GLX_BLUE_SIZE;

    attribs[i++] = _this->gl_config.blue_size;

    if (_this->gl_config.alpha_size) {

        attribs[i++] = GLX_ALPHA_SIZE;

        attribs[i++] = _this->gl_config.alpha_size;

    }

    if (_this->gl_config.double_buffer) {

        attribs[i++] = GLX_DOUBLEBUFFER;

        if( for_FBConfig ) {

            attribs[i++] = True;

        }

    }

    attribs[i++] = GLX_DEPTH_SIZE;

    attribs[i++] = _this->gl_config.depth_size;

    if (_this->gl_config.stencil_size) {

        attribs[i++] = GLX_STENCIL_SIZE;

        attribs[i++] = _this->gl_config.stencil_size;

    }

    if (_this->gl_config.accum_red_size) {

        attribs[i++] = GLX_ACCUM_RED_SIZE;

        attribs[i++] = _this->gl_config.accum_red_size;

    }

    if (_this->gl_config.accum_green_size) {

        attribs[i++] = GLX_ACCUM_GREEN_SIZE;

        attribs[i++] = _this->gl_config.accum_green_size;

    }

    if (_this->gl_config.accum_blue_size) {

        attribs[i++] = GLX_ACCUM_BLUE_SIZE;

        attribs[i++] = _this->gl_config.accum_blue_size;

    }

    if (_this->gl_config.accum_alpha_size) {

        attribs[i++] = GLX_ACCUM_ALPHA_SIZE;

        attribs[i++] = _this->gl_config.accum_alpha_size;

    }

    if (_this->gl_config.stereo) {

        attribs[i++] = GLX_STEREO;

        if( for_FBConfig ) {

            attribs[i++] = True;

        }

    }

    if (_this->gl_config.multisamplebuffers) {

        attribs[i++] = GLX_SAMPLE_BUFFERS_ARB;

        attribs[i++] = _this->gl_config.multisamplebuffers;

    }

    if (_this->gl_config.multisamplesamples) {

        attribs[i++] = GLX_SAMPLES_ARB;

        attribs[i++] = _this->gl_config.multisamplesamples;

    }

    if (_this->gl_config.framebuffer_srgb_capable) {

        attribs[i++] = GLX_FRAMEBUFFER_SRGB_CAPABLE_ARB;

        if( for_FBConfig ) {

            attribs[i++] = True;

        }

    }

    if (_this->gl_config.accelerated >= 0 &&

        _this->gl_data->HAS_GLX_EXT_visual_rating) {