1.1 --- a/src/dreamcast.c	Sat Oct 27 05:47:55 2007 +0000
     1.2 +++ b/src/dreamcast.c	Wed Oct 31 09:11:14 2007 +0000
     1.3 @@ -1,5 +1,5 @@
     1.4  /**
     1.5 - * $Id: dreamcast.c,v 1.26 2007-10-27 05:47:55 nkeynes Exp $
     1.6 + * $Id: dreamcast.c,v 1.27 2007-10-31 09:10:23 nkeynes Exp $
     1.7   * Central switchboard for the system. This pulls all the individual modules
     1.8   * together into some kind of coherent structure. This is also where you'd
     1.9   * add Naomi support, if I ever get a board to play with...
    1.10 @@ -220,62 +220,137 @@
    1.11      uint32_t module_count;
    1.12  };
    1.13  
    1.14 +struct chunk_header {
    1.15 +    char marker[4]; /* Always BLCK */
    1.16 +    char name[8]; /* Block (module) name */
    1.17 +    uint32_t block_length;
    1.18 +};
    1.19 +
    1.20 +/**
    1.21 + * Check the save state header to ensure that it is a valid, supported
    1.22 + * file. 
    1.23 + * @return the number of blocks following, or 0 if the file is invalid.
    1.24 + */
    1.25 +int dreamcast_read_save_state_header( FILE *f )
    1.26 +{
    1.27 +    struct save_state_header header;
    1.28 +    if( fread( &header, sizeof(header), 1, f ) != 1 ) {
    1.29 +	return 0;
    1.30 +    }
    1.31 +    if( strncmp( header.magic, DREAMCAST_SAVE_MAGIC, 16 ) != 0 ) {
    1.32 +	ERROR( "Not a %s save state file", APP_NAME );
    1.33 +	return 0;
    1.34 +    }
    1.35 +    if( header.version != DREAMCAST_SAVE_VERSION ) {
    1.36 +	ERROR( "%s save state version not supported", APP_NAME );
    1.37 +	return 0;
    1.38 +    }
    1.39 +    if( header.module_count > MAX_MODULES ) {
    1.40 +	ERROR( "%s save state is corrupted (bad module count)", APP_NAME );
    1.41 +	return 0;
    1.42 +    }
    1.43 +    return header.module_count;
    1.44 +}
    1.45 +
    1.46 +int dreamcast_write_chunk_header( const gchar *name, uint32_t length, FILE *f )
    1.47 +{
    1.48 +    struct chunk_header head;
    1.49 +
    1.50 +    memcpy( head.marker, "BLCK", 4 );
    1.51 +    memset( head.name, 0, 8 );
    1.52 +    memcpy( head.name, name, strlen(name) );
    1.53 +    head.block_length = length;
    1.54 +    return fwrite( &head, sizeof(head), 1, f );
    1.55 +}
    1.56 +
    1.57 +
    1.58 +frame_buffer_t dreamcast_load_preview( const gchar *filename )
    1.59 +{
    1.60 +    int i;
    1.61 +    FILE *f = fopen( filename, "r" );
    1.62 +    if( f == NULL ) return NULL;
    1.63 +    
    1.64 +    int module_count = dreamcast_read_save_state_header(f);
    1.65 +    if( module_count <= 0 ) {
    1.66 +	fclose(f);
    1.67 +	return NULL;
    1.68 +    }
    1.69 +    for( i=0; i<module_count; i++ ) {
    1.70 +	struct chunk_header head;
    1.71 +	if( fread( &head, sizeof(head), 1, f ) != 1 ) {
    1.72 +	    fclose(f);
    1.73 +	    return NULL;
    1.74 +	}
    1.75 +	if( memcmp("BLCK", head.marker, 4) != 0 ) {
    1.76 +	    fclose(f);
    1.77 +	    return NULL;
    1.78 +	}
    1.79 +
    1.80 +	if( strcmp("PVR2", head.name) == 0 ) {
    1.81 +	    uint32_t buf_count;
    1.82 +	    int has_front;
    1.83 +	    fread( &buf_count, sizeof(buf_count), 1, f );
    1.84 +	    fread( &has_front, sizeof(has_front), 1, f );
    1.85 +	    if( buf_count != 0 && has_front ) {
    1.86 +		frame_buffer_t result = read_png_from_stream(f);
    1.87 +		fclose(f);
    1.88 +		return result;
    1.89 +	    }
    1.90 +	    break;
    1.91 +	} else {
    1.92 +	    fseek( f, head.block_length, SEEK_CUR );
    1.93 +	}
    1.94 +    }
    1.95 +    return NULL;
    1.96 +}
    1.97 +
    1.98  int dreamcast_load_state( const gchar *filename )
    1.99  {
   1.100      int i,j;
   1.101      uint32_t len;
   1.102 +    int module_count;
   1.103      int have_read[MAX_MODULES];
   1.104 -    char tmp[64];
   1.105 -    struct save_state_header header;
   1.106 -    FILE *f;
   1.107  
   1.108 -    f = fopen( filename, "r" );
   1.109 +    FILE *f = fopen( filename, "r" );
   1.110      if( f == NULL ) return errno;
   1.111  
   1.112 -    fread( &header, sizeof(header), 1, f );
   1.113 -    if( strncmp( header.magic, DREAMCAST_SAVE_MAGIC, 16 ) != 0 ) {
   1.114 -	ERROR( "Not a %s save state file", APP_NAME );
   1.115 +    module_count = dreamcast_read_save_state_header(f);
   1.116 +    if( module_count <= 0 ) {
   1.117 +	fclose(f);
   1.118  	return 1;
   1.119      }
   1.120 -    if( header.version != DREAMCAST_SAVE_VERSION ) {
   1.121 -	ERROR( "%s save state version not supported", APP_NAME );
   1.122 -	return 1;
   1.123 -    }
   1.124 -    if( header.module_count > MAX_MODULES ) {
   1.125 -	ERROR( "%s save state is corrupted (bad module count)", APP_NAME );
   1.126 -	return 1;
   1.127 -    }
   1.128 +
   1.129      for( i=0; i<MAX_MODULES; i++ ) {
   1.130  	have_read[i] = 0;
   1.131      }
   1.132  
   1.133 -    for( i=0; i<header.module_count; i++ ) {
   1.134 -	fread(tmp, 4, 1, f );
   1.135 -	if( strncmp(tmp, "BLCK", 4) != 0 ) {
   1.136 +    for( i=0; i<module_count; i++ ) {
   1.137 +	struct chunk_header chunk;
   1.138 +	fread( &chunk, sizeof(chunk), 1, f );
   1.139 +	if( strncmp(chunk.marker, "BLCK", 4) != 0 ) {
   1.140  	    ERROR( "%s save state is corrupted (missing block header %d)", APP_NAME, i );
   1.141 -	    return 2;
   1.142 -	}
   1.143 -	len = fread_string(tmp, sizeof(tmp), f );
   1.144 -	if( len > 64 || len < 1 ) {
   1.145 -	    ERROR( "%s save state is corrupted (bad string)", APP_NAME );
   1.146 +	    fclose(f);
   1.147  	    return 2;
   1.148  	}
   1.149  	
   1.150  	/* Find the matching module by name */
   1.151  	for( j=0; j<num_modules; j++ ) {
   1.152 -	    if( strcmp(modules[j]->name,tmp) == 0 ) {
   1.153 +	    if( strcmp(modules[j]->name,chunk.name) == 0 ) {
   1.154  		have_read[j] = 1;
   1.155  		if( modules[j]->load == NULL ) {
   1.156  		    ERROR( "%s save state is corrupted (no loader for %s)", APP_NAME, modules[j]->name );
   1.157 +		    fclose(f);
   1.158  		    return 2;
   1.159  		} else if( modules[j]->load(f) != 0 ) {
   1.160  		    ERROR( "%s save state is corrupted (%s failed)", APP_NAME, modules[j]->name );
   1.161 +		    fclose(f);
   1.162  		    return 2;
   1.163  		}
   1.164  		break;
   1.165  	    }
   1.166  	}
   1.167  	if( j == num_modules ) {
   1.168 +	    fclose(f);
   1.169  	    ERROR( "%s save state contains unrecognized section", APP_NAME );
   1.170  	    return 2;
   1.171  	}
   1.172 @@ -315,9 +390,15 @@
   1.173      fwrite( &header, sizeof(header), 1, f );
   1.174      for( i=0; i<num_modules; i++ ) {
   1.175  	if( modules[i]->save != NULL ) {
   1.176 -	    fwrite( "BLCK", 4, 1, f );
   1.177 -	    fwrite_string( modules[i]->name, f );
   1.178 +	    uint32_t blocklen, posn1, posn2;
   1.179 +	    dreamcast_write_chunk_header( modules[i]->name, 0, f );
   1.180 +	    posn1 = ftell(f);
   1.181  	    modules[i]->save(f);
   1.182 +	    posn2 = ftell(f);
   1.183 +	    blocklen = posn2 - posn1;
   1.184 +	    fseek( f, posn1-4, SEEK_SET );
   1.185 +	    fwrite( &blocklen, sizeof(blocklen), 1, f );
   1.186 +	    fseek( f, posn2, SEEK_SET );
   1.187  	}
   1.188      }
   1.189      fclose( f );