/*

  Simple DirectMedia Layer

  Copyright (C) 1997-2012 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_config.h"

#if SDL_VIDEO_DRIVER_X11 && SDL_VIDEO_OPENGL_ES

#include "SDL_x11video.h"

#include "SDL_x11opengles.h"

#include "SDL_x11opengl.h"

#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"

#define LOAD_FUNC(NAME) \

	*((void**)&_this->gles_data->NAME) = dlsym(handle, #NAME); \

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

	{ \

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

		return -1; \

	}

/* GLES implementation of SDL OpenGL support */

void *

X11_GLES_GetProcAddress(_THIS, const char *proc)

{

    static char procname[1024];

    void *handle;

    void *retval;

    handle = _this->gles_data->egl_dll_handle;

    if (_this->gles_data->eglGetProcAddress) {

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

        if (retval) {

            return retval;

        }

    }

    handle = _this->gl_config.dll_handle;

#if defined(__OpenBSD__) && !defined(__ELF__)

#undef dlsym(x,y);

#endif

    retval = dlsym(handle, proc);

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

        procname[0] = '_';

        strcpy(procname + 1, proc);

        retval = dlsym(handle, procname);

    }

    return retval;

}

void

X11_GLES_UnloadLibrary(_THIS)

{

    if ((_this->gles_data) && (_this->gl_config.driver_loaded)) {

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

        dlclose(_this->gl_config.dll_handle);

        dlclose(_this->gles_data->egl_dll_handle);

        SDL_free(_this->gles_data);

        _this->gles_data = NULL;

        _this->gl_config.dll_handle = NULL;

        _this->gl_config.driver_loaded = 0;

    }

}

int

X11_GLES_LoadLibrary(_THIS, const char *path)

{

    void *handle;

    int dlopen_flags;

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

    if (_this->gles_data) {

        SDL_SetError("OpenGL ES context already created");

        return -1;

    }

    /* If SDL_GL_CONTEXT_EGL has been changed to 0, switch over to X11_GL functions  */

    if (_this->gl_config.use_egl == 0) {

#if SDL_VIDEO_OPENGL_GLX

        _this->GL_LoadLibrary = X11_GL_LoadLibrary;

        _this->GL_GetProcAddress = X11_GL_GetProcAddress;

        _this->GL_UnloadLibrary = X11_GL_UnloadLibrary;

        _this->GL_CreateContext = X11_GL_CreateContext;

        _this->GL_MakeCurrent = X11_GL_MakeCurrent;

        _this->GL_SetSwapInterval = X11_GL_SetSwapInterval;

        _this->GL_GetSwapInterval = X11_GL_GetSwapInterval;

        _this->GL_SwapWindow = X11_GL_SwapWindow;

        _this->GL_DeleteContext = X11_GL_DeleteContext;

        return X11_GL_LoadLibrary(_this, path);

#else

        SDL_SetError("SDL not configured with OpenGL/GLX support");

        return -1;

#endif

    }

#ifdef RTLD_GLOBAL

    dlopen_flags = RTLD_LAZY | RTLD_GLOBAL;

#else

    dlopen_flags = RTLD_LAZY;

#endif

    handle = dlopen(path, dlopen_flags);

    /* Catch the case where the application isn't linked with EGL */

    if ((dlsym(handle, "eglChooseConfig") == NULL) && (path == NULL)) {

        dlclose(handle);

        path = getenv("SDL_VIDEO_EGL_DRIVER");

        if (path == NULL) {

            path = DEFAULT_EGL;

        }

        handle = dlopen(path, dlopen_flags);

    }

    if (handle == NULL) {

        SDL_SetError("Could not load OpenGL ES/EGL library");

        return -1;

    }

    /* Unload the old driver and reset the pointers */

    X11_GLES_UnloadLibrary(_this);

    _this->gles_data = (struct SDL_PrivateGLESData *) SDL_calloc(1, sizeof(SDL_PrivateGLESData));

    if (!_this->gles_data) {

        SDL_OutOfMemory();

        return -1;

    }

    /* 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);

    _this->gles_data->egl_display =

        _this->gles_data->eglGetDisplay((NativeDisplayType) data->display);

    if (!_this->gles_data->egl_display) {

        SDL_SetError("Could not get EGL display");

        return -1;

    }

    if (_this->gles_data->

        eglInitialize(_this->gles_data->egl_display, NULL,

                      NULL) != EGL_TRUE) {

        SDL_SetError("Could not initialize EGL");

        return -1;

    }

    _this->gles_data->egl_dll_handle = handle;

    path = getenv("SDL_VIDEO_GL_DRIVER");

    handle = dlopen(path, dlopen_flags);

    if ((path == NULL) | (handle == NULL)) {

        if (_this->gl_config.major_version > 1) {

            path = DEFAULT_OGL_ES2;

            handle = dlopen(path, dlopen_flags);

        } else {

            path = DEFAULT_OGL_ES;

            handle = dlopen(path, dlopen_flags);

            if (handle == NULL) {

                path = DEFAULT_OGL_ES_PVR;

                handle = dlopen(path, dlopen_flags);

            }

        }

    }

    if (handle == NULL) {

        SDL_SetError("Could not initialize OpenGL ES library");

        return -1;

    }

    _this->gl_config.dll_handle = handle;

    _this->gl_config.driver_loaded = 1;

    if (path) {

        strncpy(_this->gl_config.driver_path, path,

                sizeof(_this->gl_config.driver_path) - 1);

    } else {

        strcpy(_this->gl_config.driver_path, "");

    }

    return 0;

}

XVisualInfo *

X11_GLES_GetVisual(_THIS, Display * display, int screen)

{

    /* 64 seems nice. */

    EGLint attribs[64];

    EGLint found_configs = 0;

    VisualID visual_id;

    int i;

    if (!_this->gles_data) {

        /* The EGL library wasn't loaded, SDL_GetError() should have info */

        return NULL;

    }

    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.major_version == 2) {

        attribs[i++] = EGL_OPENGL_ES2_BIT;

    } else {

        attribs[i++] = EGL_OPENGL_ES_BIT;

    }

    attribs[i++] = EGL_NONE;

    if (_this->gles_data->eglChooseConfig(_this->gles_data->egl_display,

                                          attribs,

                                          &_this->gles_data->egl_config, 1,

                                          &found_configs) == EGL_FALSE ||

        found_configs == 0) {

        SDL_SetError("Couldn't find matching EGL config");

        return NULL;

    }

    if (_this->gles_data->eglGetConfigAttrib(_this->gles_data->egl_display,

                                             _this->gles_data->egl_config,

                                             EGL_NATIVE_VISUAL_ID,

                                             (EGLint *) & visual_id) ==

        EGL_FALSE || !visual_id) {

        /* Use the default visual when all else fails */

        XVisualInfo vi_in;

        int out_count;

        vi_in.screen = screen;

        _this->gles_data->egl_visualinfo = XGetVisualInfo(display,

                                                          VisualScreenMask,

                                                          &vi_in, &out_count);

    } else {

        XVisualInfo vi_in;

        int out_count;

        vi_in.screen = screen;

        vi_in.visualid = visual_id;

        _this->gles_data->egl_visualinfo = XGetVisualInfo(display,

                                                          VisualScreenMask |

                                                          VisualIDMask,

                                                          &vi_in, &out_count);

    }

    return _this->gles_data->egl_visualinfo;

}

SDL_GLContext

X11_GLES_CreateContext(_THIS, SDL_Window * window)

{

    EGLint context_attrib_list[] = {

        EGL_CONTEXT_CLIENT_VERSION,

        1,

        EGL_NONE

    };

    SDL_WindowData *data = (SDL_WindowData *) window->driverdata;

    Display *display = data->videodata->display;

    XSync(display, False);

    if (_this->gl_config.major_version) {

        context_attrib_list[1] = _this->gl_config.major_version;

    }

    _this->gles_data->egl_context =

        _this->gles_data->eglCreateContext(_this->gles_data->egl_display,

                                           _this->gles_data->egl_config,

                                           EGL_NO_CONTEXT, context_attrib_list);

    XSync(display, False);

    if (_this->gles_data->egl_context == EGL_NO_CONTEXT) {

        SDL_SetError("Could not create EGL context");

        return NULL;

    }

    _this->gles_data->egl_swapinterval = 0;

    if (X11_GLES_MakeCurrent(_this, window, context) < 0) {

        X11_GLES_DeleteContext(_this, context);

        return NULL;

    }

    return context;

}

int

X11_GLES_MakeCurrent(_THIS, SDL_Window * window, SDL_GLContext context)

{

    int retval;

//    SDL_WindowData *data = (SDL_WindowData *) window->driverdata;

//    Display *display = data->videodata->display;

    if (!_this->gles_data) {

        SDL_SetError("OpenGL not initialized");

        return -1;

    }

    retval = 1;

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

                                          _this->gles_data->egl_surface,

                                          _this->gles_data->egl_surface,

                                          _this->gles_data->egl_context)) {

        SDL_SetError("Unable to make EGL context current");

        retval = -1;

    }

//    XSync(display, False);

    return (retval);

}

int

X11_GLES_SetSwapInterval(_THIS, int interval)

{

    if (_this->gles_data) {

        SDL_SetError("OpenGL ES context not active");

        return -1;

    }

    EGLBoolean status;

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

    if (status == EGL_TRUE) {

        _this->gles_data->egl_swapinterval = interval;

        return 0; 

    }

    SDL_SetError("Unable to set the EGL swap interval");

    return -1;

}

int

X11_GLES_GetSwapInterval(_THIS)

{

    if (_this->gles_data) {

        SDL_SetError("OpenGL ES context not active");

        return -1;

    }

    return _this->gles_data->egl_swapinterval;

}

void

X11_GLES_SwapWindow(_THIS, SDL_Window * window)

{

    _this->gles_data->eglSwapBuffers(_this->gles_data->egl_display,

                                     _this->gles_data->egl_surface);

}

void

X11_GLES_DeleteContext(_THIS, SDL_GLContext context)

{

    /* Clean up GLES and EGL */

    if (!_this->gles_data) {  

        return;

    }

    if (_this->gles_data->egl_context != EGL_NO_CONTEXT ||

        _this->gles_data->egl_surface != EGL_NO_SURFACE) {

        _this->gles_data->eglMakeCurrent(_this->gles_data->egl_display,

                                         EGL_NO_SURFACE, EGL_NO_SURFACE,

                                         EGL_NO_CONTEXT);

        if (_this->gles_data->egl_context != EGL_NO_CONTEXT) {

            _this->gles_data->eglDestroyContext(_this->gles_data->egl_display,

                                                _this->gles_data->

                                                egl_context);

            _this->gles_data->egl_context = EGL_NO_CONTEXT;

        }

        if (_this->gles_data->egl_surface != EGL_NO_SURFACE) {

            _this->gles_data->eglDestroySurface(_this->gles_data->egl_display,

                                                _this->gles_data->

                                                egl_surface);

            _this->gles_data->egl_surface = EGL_NO_SURFACE;

        }

    }

    /* crappy fix */

    X11_GLES_UnloadLibrary(_this);

}

#endif /* SDL_VIDEO_DRIVER_X11 && SDL_VIDEO_OPENGL_ES */

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