/**

 * $Id$

 *

 * Scene-save support. This is mainly for test/debug purposes.

 *

 * Copyright (c) 2005 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 <stdio.h>

#include <errno.h>

#include <time.h>

#include <string.h>

#include "pvr2/pvr2.h"

#include "pvr2/pvr2mmio.h"

#include "dreamcast.h"

/**

 * Size of pages for the purposes of saving - this has nothing to do with the 

 * actual page size, of course.

 */

#define SAVE_PAGE_SIZE 1024

#define SAVE_PAGE_COUNT 8192

extern char *video_base;

/* Determine pages of memory to save. Start walking from the render tilemap

 * data and build up a page list

 */

static void pvr2_find_referenced_pages( char *pages )

{

    /* Dummy implementation - save everything */

    memset( pages, 1, SAVE_PAGE_COUNT );

}

/**

 * Save the current rendering data to a file for later analysis.

 * @return 0 on success, non-zero on failure.

 */

int pvr2_render_save_scene( const gchar *filename )

{

    struct header {

        char magic[16];

        uint32_t version;

        uint32_t timestamp;

        uint32_t frame_count;

    } scene_header;

    char page_map[SAVE_PAGE_COUNT];

    int i,j;

    pvr2_find_referenced_pages(page_map);

    FILE *f = fopen( filename, "wo" ); 

    if( f == NULL ) {

        ERROR( "Unable to open file '%s' to write scene data: %s", filename, strerror(errno) );

        return -1;

    }

    /* Header */

    memcpy( scene_header.magic, SCENE_SAVE_MAGIC, 16 );

    scene_header.version = SCENE_SAVE_VERSION;

    scene_header.timestamp = time(NULL);

    scene_header.frame_count = pvr2_get_frame_count();

    fwrite( &scene_header, sizeof(scene_header), 1, f );

    /* PVR2 registers - could probably be more specific, but doesn't 

     * really use a lot of space. Loader is assumed to know which

     * registers actually need to be set.

     */

    fwrite( mmio_region_PVR2.mem, 0x1000, 1, f );

    fwrite( mmio_region_PVR2PAL.mem, 0x1000, 1, f );

    /* Write out the VRAM pages we care about */

    for( i=0; i<SAVE_PAGE_COUNT; i++ ) {

        if( page_map[i] != 0 ) {

            for( j=i+1; j<SAVE_PAGE_COUNT && page_map[j] != 0; j++ );

            /* Write region from i..j-1 */

            uint32_t start = i * SAVE_PAGE_SIZE;

            uint32_t length = (j-i) * SAVE_PAGE_SIZE;

            fwrite( &start, sizeof(uint32_t), 1, f );

            fwrite( &length, sizeof(uint32_t), 1, f );

            fwrite( video_base + start, 1, length, f );

            i = j-1;

        }

    }

    /* Write out the EOF marker */

    uint32_t eof = 0xFFFFFFFF;

    fwrite( &eof, sizeof(uint32_t), 1, f );

    fclose( f );

    return 0;

}