/**

  * $Id$

  *

  * 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;

 }