scummvm/sky/disk.cpp

/* ScummVM - Scumm Interpreter
 * Copyright (C) 2003 The ScummVM project
 *
 * 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.

 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.
 *
 * $Header$
 *
 */

#include "stdafx.h"
#include "common/scummsys.h"
#include "common/engine.h"
#include "common/file.h"
#include "sky/skydefs.h"
#include "sky/sky.h"

#define no_of_files_hd	1600
#define no_of_files_cd	5200
#define max_files_in_list	60

int UnpackM1(void *, void *, uint16);

const char *data_file_name = "sky.dsk";
const char *dinner_file_name = "sky.dnr";
uint8 *dinner_table_area, *fixed_dest, *file_dest, *comp_dest;
uint32 dinner_table_size, file_flags, file_offset, file_size, decomp_size, comp_file;
uint16 build_list[max_files_in_list];
uint32 loaded_file_list[max_files_in_list];

File *data_disk_handle = new File();
File *dnr_handle = new File();

void SkyState::initialise_disk()
{
    uint32 entries_read;
    
    dnr_handle->open(dinner_file_name, _gameDataPath);
    if (dnr_handle->isOpen() == false)
	    error("Could not open %s%s!\n", _gameDataPath, dinner_file_name);
    
    if (!(dinner_table_size = dnr_handle->readUint32LE()))
    	error("Error reading from sky.dnr!\n"); //even though it was opened correctly?!
    
    debug(1, "Entries in dinner table: %d", dinner_table_size);

    dinner_table_area = (uint8 *)malloc(dinner_table_size*8);
    entries_read = dnr_handle->read(dinner_table_area, 8*dinner_table_size) / 8;
	
    if (entries_read != dinner_table_size)
	warning("bytes_read != dinner_table_entries. [%d/%d]\n", entries_read, dinner_table_size);
        
    data_disk_handle->open(data_file_name, _gameDataPath);
    if (data_disk_handle->isOpen() == false) 
	error("Error opening %s%s!\n", _gameDataPath, data_file_name);
}

//load in file file_nr to address dest
//if dest == NULL, then allocate memory for this file
uint16 *SkyState::load_file(uint16 file_nr, uint8 *dest)
{
    uint8 cflag;
    uint32 eax, ecx;
    int32 bytes_read;
    uint8 *file_ptr, *esiptr, *ediptr;
    dataFileHeader file_header;

    #ifdef file_order_chk
	warning("File order checking not implemented yet!\n");
    #endif
    
	comp_file = file_nr;
	debug(1, "load file %d,%d (%d)", (file_nr>>11), (file_nr&2047), file_nr); 
    
    
    file_ptr = (uint8 *)get_file_info(file_nr);
    if (file_ptr == NULL) {
	printf("File %d not found!\n", file_nr);
	return NULL;
    }
    
    eax = READ_LE_UINT32((file_ptr+5));
    file_flags = eax;
    eax &= 0x03fffff;
    file_size = eax;

    ecx = READ_LE_UINT32((file_ptr+2));
    ecx &= 0x0ffffff;

    cflag = (uint8)((ecx >> (23)) & 0x1); 
    ecx = (((1 << (23)) ^ 0xFFFFFFFF) & ecx); 
    
    if (cflag)
	ecx = ecx << 4;
	
    file_offset = ecx;
    fixed_dest = dest;
    file_dest = dest;
    comp_dest = dest;

    if (dest == NULL) //we need to allocate memory for this file
	file_dest = (uint8 *)malloc(eax);
        
    data_disk_handle->seek(file_offset, SEEK_SET);

    #ifdef file_order_chk
	warning("File order checking not implemented yet!\n");
    #endif

    //now read in the data
    bytes_read = data_disk_handle->read(file_dest, 1*file_size);
    
    if (bytes_read != (int32)file_size)
	printf("ERROR: Unable to read %d bytes from datadisk (%d bytes read)\n", file_size, bytes_read);
    
    cflag = (uint8)((file_flags >> (23)) & 0x1); 
    
    //if cflag == 0 then file is compressed, 1 == uncompressed
    
    if (!cflag)
    {
	debug(1, "File is compressed...");

	memcpy(&file_header, file_dest, sizeof(struct dataFileHeader));
	if ( (uint8)((FROM_LE_16(file_header.flag) >> 7) & 0x1)  ) {
	    debug(1, "with RNC!");
	    
	    eax = FROM_LE_16(file_header.flag);
	    eax &= 0xFFFFFF00; //clear al
	    eax = eax << 8;
	    eax |= FROM_LE_16((uint16)file_header.s_tot_size);

	    decomp_size = eax;
	    
	    if (fixed_dest == NULL) // is this valid?
		comp_dest = (uint8 *)malloc(eax);

	    esiptr = file_dest;
	    ediptr = comp_dest;
		
	    if ( (uint8)(file_flags >> (22) & 0x1) ) //do we include the header?
	    	esiptr += sizeof(struct dataFileHeader);
	    else {
		memcpy(ediptr, esiptr, sizeof(struct dataFileHeader));
		esiptr += sizeof(struct dataFileHeader);
		ediptr += sizeof(struct dataFileHeader);
	    }

	    eax = UnpackM1(esiptr, ediptr, 0);
	    
	    debug(2, "UnpackM1 returned: %d", eax);

	    if (eax == 0) { //Unpack returned 0: file was probably not packed.
	    	if (fixed_dest == NULL)
		    free(comp_dest);
	    
		return (uint16 *)file_dest;
	    }
	    
	    if (! (uint8)(file_flags >> (22) & 0x1) ) { //include header?
	    	eax += sizeof(struct dataFileHeader);
	    
		if (eax != decomp_size)
		{
			debug(1, "ERROR: invalid decomp size! (was: %d, should be: %d)", eax, decomp_size);
		}
	    }
	    
	    if (fixed_dest == NULL)
		free(file_dest);
	    	    
	}
	else
		debug(1, "but not with RNC! (?!)");
	  
    }
    else
    	return (uint16 *)file_dest;
        
    return (uint16 *)comp_dest;
}

uint16 *SkyState::get_file_info(uint16 file_nr)
{
    uint16 i;
    uint16 *dnr_tbl_16_ptr = (uint16 *)dinner_table_area; 
    
    for (i = 0; i < dinner_table_size/2; i++)
    {
	if (READ_LE_UINT16(dnr_tbl_16_ptr+(i*4)) == file_nr)
	{
	    debug(1, "file %d found!", file_nr);
	    return (dnr_tbl_16_ptr+(i*4));
	}
    }
    
    //if file is speech file then return NULL if not found
    printf("get_file_info() - speech file support not implemented yet!\n");
    return (uint16 *)NULL;
}