Patch #697312: Beneath a Steel Sky interim/initial support patch

svn-id: r6691

8 files changed, 1283 insertions, 0 deletions

diff --git a/sky/disk.cpp b/sky/disk.cpp
new file mode 100644
index 0000000000..8649b699b3
--- /dev/null
+++ b/sky/disk.cpp
@@ -0,0 +1,211 @@
+/* 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 "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
+
+extern uint16 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;
+    s 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 s));
+	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 s);
+	    else {
+		memcpy(ediptr, esiptr, sizeof(struct s));
+		esiptr += sizeof(struct s);
+		ediptr += sizeof(struct s);
+	    }
+
+	    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 s);
+	    
+		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;
+}
+
diff --git a/sky/intro.cpp b/sky/intro.cpp
new file mode 100644
index 0000000000..b13d8ebece
--- /dev/null
+++ b/sky/intro.cpp
@@ -0,0 +1,266 @@
+/* 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 <string.h>
+#include "common/scummsys.h"
+#include "sky/skydefs.h"
+#include "sky/sky.h"
+
+#define intro_text_width	128
+
+#define	fn_a_pal	60080
+#define	fn_1a_log	60081
+#define	fn_1a	60082
+#define fn_1b	60083
+#define fn_1c	60084
+#define	fn_1d	60085
+#define	fn_1e	60086
+#define	fn_4a	60087
+#define	fn_4b_log	60088
+#define	fn_4b	60089
+#define	fn_4c_log	60090
+#define	fn_4c	60091
+#define	fn_5_pal	60092
+#define	fn_5_log	60093
+#define	fn_5	60094
+#define	fn_6_pal	60095
+#define	fn_6_log	60096
+#define	fn_6a	60097
+#define	fn_6b	60098
+
+#ifdef short_intro_start
+#define virgin_time_1	3
+#define viring_time_2	3
+#define rev_time	8
+#define gibb_time	6
+#else
+#define virgin_time_1	(3*50)
+#define virgin_time_2	((3*50)+8)
+#define rev_time	((8*50)+8)
+#define gibb_time	((6*50)+8)
+#endif
+
+void prepare_text(void);
+void show_intro_text(void);
+void remove_text(void);
+void intro_fx(void);
+void intro_vol(void);
+
+uint8 *seq1a_data;
+uint8 *seq1b_data;
+uint8 *seq1c_data;
+uint8 *seq1d_data;
+uint8 *seq1e_data;
+uint8 *seq4a_data;
+uint8 *seq4b_data;
+uint8 *seq4c_data;
+uint8 *seq5_data;
+uint8 *seq6a_data;
+uint8 *seq6b_data;
+
+
+uint8 *vga_data;
+uint8 *diff_data;
+
+uint8 *work_base;
+uint8 *work_screen;
+uint8 *work_screen_end;
+
+uint8 *intro_text_space;	//space for storing text messages
+uint8 *intro_text_save;	//save screen data here
+
+uint8 *vga_pointer;
+uint8 *diff_pointer;
+
+uint32 no_frames;	//number of frames in scrolling intro
+uint32 frame_counter;
+
+#define ic_prepare_text	0
+#define	ic_show_text	1
+#define	ic_remove_text	2
+#define	ic_make_sound	3
+#define	ic_fx_volume	4
+
+
+typedef void (*pfc)(void);
+pfc command_routines[] = { &prepare_text, &show_intro_text, &remove_text, &intro_fx, &intro_vol };
+
+uint32 cockpit_commands[] = 
+{
+    1000,	//do straight away
+    ic_prepare_text,
+    77,
+    220,
+    ic_show_text, //radar detects jamming signal
+    20,
+    160,
+    105,
+    ic_remove_text,
+    81,
+    105,
+    ic_show_text, //well switch to override you fool
+    170,
+    86,
+    35,
+    ic_remove_text,
+    35,
+    ic_prepare_text,
+    477,
+    35,
+    ic_show_text,
+    30,
+    160,
+    3,
+    ic_remove_text
+};
+
+uint32 zero_commands[] = { 0 };
+
+uint32 anim5_commands[] = 
+{
+    31,
+    ic_make_sound,
+    2,
+    127,
+    0
+};
+
+uint32 anim4a_commands[] = 
+{
+    136,
+    ic_make_sound,
+    1,
+    70,
+    90,
+    ic_fx_volume,
+    80,
+    50,
+    ic_fx_volume,
+    90,
+    5,
+    ic_fx_volume,
+    100,
+    0
+};
+
+uint32 anim4c_commands[] =
+{
+    1000,
+    ic_fx_volume,
+    100,
+    25,
+    ic_fx_volume,
+    110,
+    15,
+    ic_fx_volume,
+    120,
+    4,
+    ic_fx_volume,
+    127,
+    0
+};
+
+uint32 anim6a_commands[] =
+{
+    1000,
+    ic_prepare_text,
+    478,
+    13,
+    ic_show_text,
+    175,
+    155,
+    0
+};
+
+uint32 anim6b_commands[] = 
+{
+    131,
+    ic_remove_text,
+    131,
+    ic_prepare_text,
+    479,
+    74,
+    ic_show_text,
+    175,
+    155,
+    45,
+    ic_remove_text,
+    45,
+    ic_prepare_text,
+    162,
+    44,
+    ic_show_text,
+    175,
+    155,
+    4,
+    ic_remove_text,
+    0
+};
+
+uint32 *command_pointer = (uint32 *)zero_commands;
+
+
+void SkyState::init_virgin()
+{
+    _temp_pal = (uint8 *)load_file(60111, NULL); 
+    if (_temp_pal != NULL)
+	    set_palette(_temp_pal);
+
+    _work_screen = (uint8 *)load_file(60110, NULL); 
+
+    if (_work_screen != NULL)
+	    show_screen();
+    
+    //free the memory that was malloc'ed indirectly via load_file
+    free (_work_screen);
+    free (_temp_pal);
+}
+
+void SkyState::show_screen(void)
+{
+	_system->copy_rect(_work_screen, 320, 0, 0, 320, 200);
+	_system->update_screen();
+}
+
+void prepare_text(void)
+{
+
+}
+
+void show_intro_text(void)
+{
+
+}
+
+void remove_text(void)
+{
+
+}
+
+void intro_fx(void)
+{
+
+}
+
+void intro_vol(void)
+{
+
+}
diff --git a/sky/rnc_deco.cpp b/sky/rnc_deco.cpp
new file mode 100644
index 0000000000..975f3736da
--- /dev/null
+++ b/sky/rnc_deco.cpp
@@ -0,0 +1,345 @@
+/* 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 <string.h>
+#include "common/scummsys.h"
+
+#define ROL(x, n) (((x) << (n)) | ((x) >> (16-(n))))
+#define ROR(x, n) (((x) << (16-(n))) | ((x) >> (n)))
+#define XCHG(a, b) (a ^=b, b ^= a, a ^= b)
+
+//conditional flags
+#define CHECKSUMS       1
+#define PROTECTED       0
+
+//return codes
+#define NOT_PACKED      0
+#define PACKED_CRC      -1
+#define UNPACKED_CRC    -2
+
+//other defines
+#define TABLE_SIZE      (16*8)
+#define MIN_LENGTH      2
+#define HEADER_LEN      18
+
+uint16 raw_table[TABLE_SIZE/2];
+uint16 pos_table[TABLE_SIZE/2];
+uint16 len_table[TABLE_SIZE/2];
+
+#ifdef CHECKSUMS
+uint16 crc_table[0x100];
+#endif
+
+uint32 unpack_len = 0;
+uint32 pack_len = 0;
+uint16 pack_paras = 0;
+uint16 counts = 0;
+uint16 bit_buffl = 0;
+uint16 bit_buffh = 0;
+uint8 blocks = 0;
+uint8 bit_count = 0;
+
+#ifdef CHECKSUMS
+uint16 crc_u = 0;
+uint16 crc_p = 0;
+#endif
+
+
+uint8 *esiptr, *ediptr; //these need to be global because input_bits() uses them
+
+void init_crc(void)
+{
+	uint16 cnt=0; 
+	uint16 tmp1=0; 
+	uint16 tmp2=0; 
+
+	for (tmp2 = 0; tmp2 < 0x100; tmp2++) {
+        	tmp1 = tmp2; 
+		for (cnt = 8; cnt > 0; cnt--) {
+                        if (tmp1 % 2) {
+				tmp1 /= 2;
+				tmp1 ^= 0x0a001;
+			}
+                        else
+                                tmp1 /= 2;
+		}
+                crc_table[tmp2] = tmp1;
+	}
+}
+
+//calculate 16 bit crc of a block of memory
+uint16 crc_block(uint8 *block, uint32 size)
+{
+	uint16 crc=0;
+	uint8 *crcTable8 = (uint8 *)crc_table; //make a uint8* to crc_table
+	uint8 tmp; 
+	uint32 i; 
+        
+	for (i = 0; i < size; i++) {
+		tmp = *block++;
+		crc ^= tmp; 
+                tmp = (uint8)((crc>>8)&0x00FF); 
+                crc &= 0x00FF;  
+		crc = crc << 1; 
+                crc = *(uint16 *)&crcTable8[crc];
+                crc ^= tmp; 
+	}
+
+	return crc;
+}
+
+uint16 input_bits(uint8 amount)
+{
+	uint16 newBitBuffh = bit_buffh;
+	uint16 newBitBuffl = bit_buffl;
+        int16 newBitCount = bit_count;
+	uint16 remBits, returnVal;
+
+	returnVal = ((1 << amount) - 1) & newBitBuffl;	
+	newBitCount -= amount;
+
+	if (newBitCount < 0) {
+		newBitCount += amount;
+		XCHG(newBitCount, amount);
+		remBits = ROR((uint16)(((1 << amount) - 1) & newBitBuffh), amount);
+		newBitBuffh >>= amount;
+		newBitBuffl >>= amount;
+		newBitBuffl |= remBits;	
+		esiptr += 2;
+		newBitBuffh = READ_LE_UINT16(esiptr);
+		XCHG(newBitCount, amount);
+		amount -= newBitCount;
+		newBitCount = 16 - amount;				
+	}
+	remBits = ROR((uint16)(((1 << amount) - 1) & newBitBuffh), amount);
+	bit_buffh = newBitBuffh >> amount;
+	bit_buffl = (newBitBuffl >> amount) | remBits;
+	bit_count = newBitCount;
+
+	return returnVal;
+
+}
+
+// RCL/RCR functions..operate on 16 bit ints only
+uint16 rcl(uint16 reg, uint16 *cflag)
+{
+        uint16 lsb = *cflag;
+        *cflag = reg >> 15;
+        return (reg << 1) | lsb;
+}
+
+uint16 rcr(uint16 reg, uint16 *cflag)
+{
+        uint16 msb = *cflag << 15;
+	*cflag = reg & 1;
+	return (reg >> 1) | msb;
+}
+
+
+
+void make_huftable(uint16 *table) 
+{
+	uint16 bitLength, i, j;
+	uint16 numCodes = input_bits(5);
+
+	if (!numCodes)
+		return;
+
+	uint8 huffLength[16];
+	for (i = 0; i < numCodes; i++)
+		huffLength[i] = (uint8)(input_bits(4) & 0x00FF);
+
+	uint16 huffCode = 0;
+
+	for (bitLength = 1; bitLength < 17; bitLength++) {
+		for (i = 0; i < numCodes; i++) {
+			if (huffLength[i] == bitLength) {
+				*table++ = (1 << bitLength) - 1;
+
+				uint16 b = huffCode >> (16 - bitLength);
+				uint16 a = 0;
+				uint16 carry = 0;
+
+				for (j = 0; j < bitLength; j++) {
+					b = rcr(b, &carry);
+					a = rcl(a, &carry);
+					
+				}
+				*table++ = a;
+
+				*(table+0x1e) = (huffLength[i]<<8)|(i & 0x00FF);
+				huffCode += 1 << (16 - bitLength);
+			}
+		}
+	}
+}
+
+
+uint16 input_value(uint16 *table)
+{
+	uint16 valOne, valTwo, value = bit_buffl;
+	
+	do {
+		valTwo = (*table++) & value;
+		valOne = *table++;
+	
+	} while (valOne != valTwo);	
+
+	value = *(table+0x1e);
+	input_bits((uint8)((value>>8)&0x00FF));
+	value &= 0x00FF; 
+
+	if (value >= 2) {
+		value--;
+		valOne = input_bits((uint8)value&0x00FF);
+		valOne |= (1 << value);
+		value = valOne;
+	}
+
+	return value;
+}
+
+int UnpackM1(void *input, void *output, uint16 key)
+{
+ 	uint8 cl;
+	uint8 *inputHigh, *outputLow;
+	uint32 eax, ebx, ecx, edx;       
+        uint8 *inputptr = (uint8 *)input;
+
+        if (CHECKSUMS)
+                init_crc();
+
+        //Check for "RNC " 
+        if (READ_BE_UINT32(inputptr) != 0x524e4301)
+                return NOT_PACKED;
+
+        inputptr += 4;
+
+        // read unpacked/packed file length
+        unpack_len = READ_BE_UINT32(inputptr); inputptr += 4;
+        pack_len = READ_BE_UINT32(inputptr); inputptr += 4;
+
+        blocks = *(inputptr+5);
+
+        if (CHECKSUMS) {
+                //read CRC's
+                crc_u = READ_BE_UINT16(inputptr); inputptr += 2;
+                crc_p = READ_BE_UINT16(inputptr); inputptr += 2;
+                
+                inputptr = (inputptr+HEADER_LEN-16);
+                
+		if (crc_block(inputptr, pack_len) != crc_p)
+                        return PACKED_CRC;
+
+                inputptr = (((uint8 *)input)+HEADER_LEN); 
+                esiptr = inputptr;
+
+        }
+
+	inputHigh = ((uint8 *)input) + pack_len + HEADER_LEN;;
+	outputLow = (uint8 *)output;
+
+	eax = *(((uint8 *)input)+16) + unpack_len;
+
+	if (! ((inputHigh <= outputLow ) || ((outputLow+eax) <= inputHigh )) ) {
+		esiptr = inputHigh;
+		ediptr = (outputLow+eax);
+                memcpy((ediptr-pack_len), (esiptr-pack_len), pack_len);
+                esiptr = (ediptr-pack_len);
+	}
+
+
+	//unpack3:
+        ediptr = (uint8 *)output;
+        bit_count = 0;
+
+        bit_buffl = READ_LE_UINT16(esiptr);
+        /*eax =*/ input_bits(2);
+
+	
+	//Argh! Labels!!
+  unpack4:
+	make_huftable(raw_table);
+	make_huftable(pos_table);
+	make_huftable(len_table);
+
+	counts = input_bits(16);
+	
+	goto unpack6;
+
+  unpack5:
+
+	eax = input_value(pos_table) + 1; //input offset
+	ecx = input_value(len_table) + MIN_LENGTH; //input length
+
+	inputHigh = esiptr;
+	esiptr = (ediptr-eax);
+
+	//Don't use memcpy here! because input and output overlap	
+	while (ecx) {
+		*ediptr++ = *esiptr++; ecx--;
+	}
+	
+	esiptr = inputHigh;
+
+  unpack6:
+	
+	ecx = input_value(raw_table);
+
+	if (ecx == 0)
+		goto unpack7;
+
+	memcpy(ediptr, esiptr, ecx); //memcpy is allowed here
+	ediptr += ecx;
+	esiptr += ecx;
+	cl = bit_count;
+	eax = READ_LE_UINT16(esiptr);
+	ebx = eax;
+	eax = ROL((uint16)eax, cl);
+	edx = ((1 << cl) - 1) & 0x0000FFFF; //make sure we only get 16bits
+	bit_buffl &= (uint16)edx;
+	edx &= eax;
+
+	eax = READ_LE_UINT16((esiptr+2));
+	ebx = (ebx << cl)&0x0000FFFF;
+	eax = (eax << cl)&0x0000FFFF;
+	eax |= edx;
+	bit_buffl |= (uint16)ebx;
+	bit_buffh = (uint16)eax;
+  
+  unpack7:
+
+	counts--;
+	if (counts)
+		goto unpack5;
+
+	blocks--;
+	if (blocks)
+		goto unpack4;
+
+	if (CHECKSUMS) {
+		if (crc_block((uint8 *)output, unpack_len) != crc_u)
+			return UNPACKED_CRC;
+	}
+
+        // all is done..return the amount of unpacked bytes
+        return unpack_len;
+}
diff --git a/sky/screen.cpp b/sky/screen.cpp
new file mode 100644
index 0000000000..c262a7b434
--- /dev/null
+++ b/sky/screen.cpp
@@ -0,0 +1,96 @@
+/* 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 <string.h>
+#include "common/scummsys.h"
+#include "sky/skydefs.h"
+#include "sky/sky.h"
+
+#define	fade_jump	2
+#define	scroll_jump	16
+
+#define	vga_colours	256
+#define	game_colours	240
+
+uint8 top_16_colours[] =
+{
+    0, 0, 0,
+    38, 38, 38,
+    63, 63, 63,
+    0, 0, 0,
+    0, 0, 0,
+    0, 0, 0,
+    0, 0, 0,
+    54, 54, 54,
+    45, 47, 49,
+    32, 31, 41,
+    29, 23, 37,
+    23, 18, 30,
+    49, 11, 11,
+    39, 5, 5,
+    29, 1, 1,
+    63, 63, 63
+};
+
+void SkyState::initialise_screen(void)
+{
+    int i;
+    uint8 tmp_pal[1024];
+    
+    _system->init_size(full_screen_width, full_screen_height);
+    _backscreen = (uint8 *)malloc(full_screen_width*full_screen_height);
+    _game_grid = (uint8 *)malloc(GRID_X*GRID_Y*2);
+    _work_palette = (uint8 *)malloc(vga_colours*3);
+
+    //blank the first 240 colors of the palette 
+    bzero(tmp_pal, game_colours*4);   
+
+    //set the remaining colors
+    for (i=0; i<(vga_colours-game_colours); i++) {
+	tmp_pal[game_colours+i*4] = (top_16_colours[i*3] << 2) + (top_16_colours[i*3] & 3);	
+	tmp_pal[game_colours+i*4+1] = (top_16_colours[i*3+1] << 2) + (top_16_colours[i*3+1] & 3);
+	tmp_pal[game_colours+i*4+2] = (top_16_colours[i*3+2] << 2) + (top_16_colours[i*3+2] & 3);
+	tmp_pal[game_colours+i*4+3] = 0x00; 
+    }
+
+    //set the palette
+    _system->set_palette(tmp_pal, 0, 256);
+
+}
+
+//set a new palette, pal is a pointer to dos vga rgb components 0..63
+void SkyState::set_palette(uint8 *pal)
+{
+    convert_palette(pal, _palette);
+    _system->set_palette(_palette, 0, 256);
+}
+
+void SkyState::convert_palette(uint8 *inpal, uint8* outpal) //convert 3 byte 0..63 rgb to 4byte 0..255 rgbx
+{
+    int i;
+
+    for (i = 0; i < vga_colours; i++) {
+	outpal[4*i] = (inpal[3*i] << 2) + (inpal[3*i] & 3); 
+	outpal[4*i+1] = (inpal[3*i+1] << 2) + (inpal[3*i+1] & 3); 
+	outpal[4*i+2] = (inpal[3*i+2] << 2) + (inpal[3*i+2] & 3); 
+	outpal[4*i+3] = 0x00;	
+    }
+}
diff --git a/sky/sky.cpp b/sky/sky.cpp
new file mode 100644
index 0000000000..2006c9aead
--- /dev/null
+++ b/sky/sky.cpp
@@ -0,0 +1,148 @@
+/* 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 "sky/sky.h"
+#include "sky/skydefs.h" //game specific defines
+#include "common/file.h"
+#include "common/gameDetector.h"
+#include <errno.h>
+#include <time.h>
+
+#ifdef _WIN32_WCE
+
+extern bool toolbar_drawn;
+extern bool draw_keyboard;
+
+#endif
+
+static const VersionSettings sky_settings[] = {
+	/* Beneath a Steel Sky */
+	{"sky", "Beneath a Steel Sky", GID_SKY_FIRST, 99, 99, 99, 0, "sky.dsk" },
+	{NULL, NULL, 0, 0, 0, 0, 0, NULL}
+};
+
+const VersionSettings *Engine_SKY_targetList()
+{
+	return sky_settings;
+}
+
+Engine *Engine_SKY_create(GameDetector *detector, OSystem *syst)
+{
+	return new SkyState(detector, syst);
+}
+
+SkyState::SkyState(GameDetector *detector, OSystem *syst)
+	: Engine(detector, syst)
+{
+	_game = detector->_gameId;
+
+	_debugMode = detector->_debugMode;
+	_debugLevel = detector->_debugLevel;
+ 	_language = detector->_language;
+}
+
+SkyState::~SkyState()
+{
+	
+}
+
+void SkyState::pollMouseXY()
+{
+	_mouse_x = _sdl_mouse_x;
+	_mouse_y = _sdl_mouse_y;
+}
+
+void SkyState::go()
+{
+	if (!_dump_file)
+		_dump_file = stdout;
+
+	initialise();
+
+	while (1) {
+		delay(100);
+	}
+}
+
+void SkyState::initialise(void)
+{
+    //initialise_memory();
+    //init_timer();
+    //init_music(); 
+    initialise_disk();
+    initialise_screen();    
+    init_virgin();
+    
+}
+
+void SkyState::delay(uint amount) //copied and mutilated from Simon.cpp
+{
+	OSystem::Event event;
+
+	uint32 start = _system->get_msecs();
+	uint32 cur = start;
+
+	_rnd.getRandomNumber(2);
+
+	do {
+		while (_system->poll_event(&event)) {
+			switch (event.event_code) {
+				case OSystem::EVENT_KEYDOWN:
+					// Make sure backspace works right (this fixes a small issue on OS X)
+					if (event.kbd.keycode == 8)
+						_key_pressed = 8;
+					else
+						_key_pressed = (byte)event.kbd.ascii;
+					break;
+
+				case OSystem::EVENT_MOUSEMOVE:
+					_sdl_mouse_x = event.mouse.x;
+					_sdl_mouse_y = event.mouse.y;
+					_mouse_pos_changed = true;
+					break;
+
+					case OSystem::EVENT_LBUTTONDOWN:
+					_left_button_down++;
+#ifdef _WIN32_WCE
+					_sdl_mouse_x = event.mouse.x;
+					_sdl_mouse_y = event.mouse.y;
+#endif
+					break;
+
+				case OSystem::EVENT_RBUTTONDOWN:
+					
+					break;
+			}
+		}
+
+		if (amount == 0)
+			break;
+
+		{
+			uint this_delay = 20; // 1?
+			if (this_delay > amount)
+				this_delay = amount;
+			_system->delay_msecs(this_delay);
+		}
+		cur = _system->get_msecs();
+	} while (cur < start + amount);
+}
+
diff --git a/sky/sky.h b/sky/sky.h
new file mode 100644
index 0000000000..89b2417e71
--- /dev/null
+++ b/sky/sky.h
@@ -0,0 +1,89 @@
+/* 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.
+ *
+ * $Header$
+ *
+ */
+
+#ifndef SKYMAIN_H
+#define SKYMAIN_H
+
+#include <stdio.h>
+#include "common/engine.h"
+#include "common/util.h"
+
+class SkyState : public Engine {
+public:
+	
+	byte _game;
+	byte _key_pressed;
+
+	uint16 _debugMode;
+	uint16 _debugLevel;
+	uint16 _language;
+	uint _mouse_x, _mouse_y;
+	uint _mouse_x_old, _mouse_y_old;
+	bool _mouse_pos_changed;
+	uint _left_button_down;
+
+	uint8 _palette[1024];
+
+	int _num_screen_updates;
+
+//	int _timer_id;
+
+	FILE *_dump_file;
+
+	int _number_of_savegames;
+
+	int _sdl_mouse_x, _sdl_mouse_y;
+	
+	byte *_work_screen;
+	byte *_backscreen;
+	byte *_temp_pal;
+	byte *_work_palette;
+	byte *_half_palette;
+
+	byte *_game_grid;
+
+	SkyState(GameDetector *detector, OSystem *syst);
+	virtual ~SkyState();
+
+	void delay(uint amount);
+	void pollMouseXY();
+	void go();
+	void convert_palette(uint8 *inpal, uint8* outpal);	
+
+	void initialise();
+	void initialise_disk();
+	void initialise_screen();
+	void set_palette(uint8 *pal);
+	uint16 *load_file(uint16 file_nr, uint8 *dest);
+	uint16 *get_file_info(uint16 file_nr);
+	void init_virgin();
+	void show_screen();
+
+	static int CDECL game_thread_proc(void *param);
+
+	void shutdown();
+	
+	RandomSource _rnd;
+
+
+};
+
+#endif
diff --git a/sky/skydefs.h b/sky/skydefs.h
new file mode 100644
index 0000000000..292dce6523
--- /dev/null
+++ b/sky/skydefs.h
@@ -0,0 +1,90 @@
+/* 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 "struc.h"
+
+//This file is incomplete, several flags still missing.
+
+#define key_buffer_size	80
+#define sequence_count	3
+
+//screen/grid defines
+#define	game_screen_width	320
+#define	game_screen_height	192
+#define	full_screen_width	320
+#define	full_screen_height	200
+
+#define	tot_no_grids	70
+
+#define	grid_size	120
+
+#define	GRID_X	20
+#define	GRID_Y	24
+#define	GRID_W	16
+#define	GRID_H	8
+
+#define	GRID_W_SHIFT	4
+#define	GRID_H_SHIFT	3
+
+#define top_left_x	128
+#define	top_left_y	136
+
+//item list defines
+#define section_0_item	119
+
+#define c_base_mode	0
+#define c_base_mode56	56
+#define c_action_mode	4
+#define c_sp_colour	90
+#define	c_mega_set	112
+#define c_grid_width	114
+
+//#define next_mega_set
+
+#define	send_sync	-1
+#define	lf_start_fx	-2
+#define safe_start_screen	0
+
+//autoroute defines
+#define	upy	0
+#define	downy	1
+#define	lefty	2
+#define	righty	3
+
+#define	route_space	64
+
+#define l_script	1
+#define	l_ar	2
+#define	l_ar_anim	3
+#define	l_ar_turning	4
+#define	l_alt	5
+#define	l_mod_animate	6
+#define	l_turning	7
+#define	l_cursor	8
+#define l_talk	9
+#define	l_listen	10
+#define	l_stopped	11
+#define	l_choose	12
+#define	l_frames	13
+#define	l_pause	14
+#define	l_wait_synch	15
+#define l_simple_mod	16
+
diff --git a/sky/struc.h b/sky/struc.h
new file mode 100644
index 0000000000..56d1a305ab
--- /dev/null
+++ b/sky/struc.h
@@ -0,0 +1,38 @@
+/* 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.
+ *
+ * $Header$
+ *
+ */
+
+typedef struct s
+{
+    uint16 flag; // bit 0: set for colour data, clear for not
+		 // bit 1: set for compressed, clear for uncompressed
+		 // bit 2: set for 32 colours, clear for 16 colours
+    uint16 s_x;
+    uint16 s_y;
+    uint16 s_width;
+    uint16 s_height;
+    uint16 s_sp_size;
+    uint16 s_tot_size;
+    uint16 s_n_sprites;
+    uint16 s_offset_x;
+    uint16 s_offset_y;
+    uint16 s_compressed_size;
+}s;
+