/**

 * $Id$

 *

 * Window management using EGL.

 *

 * Copyright (c) 2012 Nathan Keynes.

 *

 * This program is free software; you can redistribute it and/or modify

 * it under the terms of the GNU General Public License as published by

 * the Free Software Foundation; either version 2 of the License, or

 * (at your option) any later version.

 *

 * This program is distributed in the hope that it will be useful,

 * but WITHOUT ANY WARRANTY; without even the implied warranty of

 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the

 * GNU General Public License for more details.

 */

#include "lxdream.h"

#include "display.h"

#include "video_egl.h"

#include "video_gl.h"

#include "pvr2/pvr2.h"

#include "pvr2/glutil.h"

static const char *getEGLErrorString( EGLint code )

{

    switch( code ) {

    case EGL_SUCCESS: return "OK";

    case EGL_NOT_INITIALIZED: return "EGL not initialized";

    case EGL_BAD_ACCESS: return "Bad access";

    case EGL_BAD_ALLOC: return "Allocation failed";

    case EGL_BAD_ATTRIBUTE: return "Bad attribute";

    case EGL_BAD_CONTEXT: return "Bad context";

    case EGL_BAD_CONFIG: return "Bad config";

    case EGL_BAD_CURRENT_SURFACE: return "Bad current surface";

    case EGL_BAD_DISPLAY: return "Bad display";

    case EGL_BAD_MATCH: return "Bad match";

    case EGL_BAD_PARAMETER: return "Bad parameter";

    case EGL_BAD_NATIVE_PIXMAP: return "Bad native pixmap";

    case EGL_BAD_NATIVE_WINDOW: return "Bad native window";

    default: return "Unknown error";

    }

}

static void logEGLError(const char *msg)

{

    EGLint error = eglGetError();

    const char *errorStr = getEGLErrorString(error);

    ERROR( "%s: %s (%x)", msg, errorStr, error );

}

static const EGLint RGB888_attributes[] = {

        EGL_RED_SIZE,       8,

        EGL_GREEN_SIZE,     8,

        EGL_BLUE_SIZE,      8,

        EGL_DEPTH_SIZE,     16,

        EGL_STENCIL_SIZE,   8,

        EGL_SURFACE_TYPE,   EGL_WINDOW_BIT,

        EGL_RENDERABLE_TYPE,EGL_OPENGL_ES2_BIT,

        EGL_NONE, EGL_NONE };

static const EGLint RGB565_attributes[] = {

        EGL_RED_SIZE,       5,

        EGL_GREEN_SIZE,     6,

        EGL_BLUE_SIZE,      5,

        EGL_DEPTH_SIZE,     16,

        EGL_STENCIL_SIZE,   8,

        EGL_SURFACE_TYPE,   EGL_WINDOW_BIT,

        EGL_RENDERABLE_TYPE,EGL_OPENGL_ES2_BIT,

        EGL_NONE, EGL_NONE };

static const EGLint alt_attributes[] = {

        EGL_DEPTH_SIZE,     16,

        EGL_STENCIL_SIZE,   8,

        EGL_SURFACE_TYPE,   EGL_WINDOW_BIT,

        EGL_RENDERABLE_TYPE,EGL_OPENGL_ES2_BIT,

        EGL_NONE, EGL_NONE };

static const EGLint context_attributes[] = {

        EGL_CONTEXT_CLIENT_VERSION, 2,

        EGL_NONE, EGL_NONE };

static EGLDisplay display = EGL_NO_DISPLAY;

static EGLContext context = EGL_NO_CONTEXT;

static EGLSurface surface = EGL_NO_SURFACE;

static gboolean fbo_created = FALSE;

static void video_egl_swap_buffers();

static int video_egl_major = 0, video_egl_minor = 0;

gboolean video_egl_init()

{

    display = eglGetDisplay(EGL_DEFAULT_DISPLAY);

    if( eglInitialize(display, &video_egl_major, &video_egl_minor) != EGL_TRUE ) {

        logEGLError( "Unable to initialise EGL display" );

        return FALSE;

    }

    return TRUE;

}

gboolean video_egl_init_context( EGLNativeWindowType window, int format )

{

    EGLConfig config;

    EGLint num_config;

    const EGLint *attribute_list;

    if( format == COLFMT_RGB565 || format == COLFMT_BGRA1555 ) {

        attribute_list = RGB565_attributes;

    } else {

        attribute_list = RGB888_attributes;

    }

    eglChooseConfig(display, attribute_list, &config, 1, &num_config);

    surface = eglCreateWindowSurface(display, config, window, NULL);

    if( surface == EGL_NO_SURFACE ) {

        /* Try alternate config in case of failure. This provides a workaround for

         * the Nokia N900 where eglCreateWindowSurface fails when color attributes

         * are specified. (bug report: https://bugs.maemo.org/show_bug.cgi?id=9335)

         */

        eglChooseConfig(display, alt_attributes, &config, 1, &num_config);

        surface = eglCreateWindowSurface(display, config, window, NULL);

        if( surface == EGL_NO_SURFACE ) {

            logEGLError( "Unable to create EGL surface" );

            video_egl_shutdown();

            return FALSE;

        }

    }

    context = eglCreateContext(display, config, EGL_NO_CONTEXT, context_attributes);

    if( context == EGL_NO_CONTEXT ) {

        logEGLError( "Unable to create EGL context" );

        video_egl_shutdown();

        return FALSE;

    }

    if( eglMakeCurrent( display, surface, surface, context ) == EGL_FALSE ) {

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

        video_egl_shutdown();

        return FALSE;

    }

    return TRUE;

}

gboolean video_egl_init_driver( display_driver_t driver )

{

    driver->swap_buffers = video_egl_swap_buffers;

    driver->capabilities.depth_bits = 16; /* TODO: get from config info */

    if( !gl_init_driver(driver, TRUE) ) {

        video_egl_shutdown();

        return FALSE;

    }

    fbo_created = TRUE;

    return TRUE;

}

void video_egl_shutdown()

{

    if( fbo_created ) {

        pvr2_shutdown_gl_context();

        gl_fbo_shutdown();

        fbo_created = FALSE;

    }

    eglMakeCurrent(display, EGL_NO_SURFACE, EGL_NO_SURFACE, EGL_NO_CONTEXT);

    if( surface != EGL_NO_SURFACE )  {

        eglDestroySurface(display, surface);

        surface = EGL_NO_SURFACE;

    }

    if( context != EGL_NO_CONTEXT ) {

        eglDestroyContext(display, context);

        context = EGL_NO_CONTEXT;

    }

    if( display != EGL_NO_DISPLAY ) {

        eglTerminate(display);

        display = EGL_NO_DISPLAY;

    }

}

gboolean video_egl_set_window(EGLNativeWindowType window, int width, int height, int format)

{

    if( ! video_egl_init() ||

            ! video_egl_init_context( window, format ) ||

            ! video_egl_init_driver( &display_egl_driver ) ) {

        return FALSE;

    }

    gl_set_video_size(width, height, 0);

    pvr2_setup_gl_context();

    INFO( "Initialised EGL %d.%d", video_egl_major, video_egl_minor );

    return TRUE;

}

void video_egl_clear_window()

{

    video_egl_shutdown();

    INFO( "Terminated EGL" );

}

static void video_egl_swap_buffers()

{

    eglSwapBuffers(display, surface);

}

/**

 * Minimal init and shutdown. The real work is done from set_window

 */

struct display_driver display_egl_driver = {

        "egl", N_("OpenGLES driver"), NULL, NULL,

        NULL, NULL, NULL,

        NULL, NULL, NULL, NULL,

        gl_load_frame_buffer, gl_display_render_buffer, gl_display_blank,

        video_egl_swap_buffers, gl_read_render_buffer, NULL, NULL

};