History Line 1914-1918

2023-03-24T09:34:30Z

DragonSphere:

History Line 1914-1918

2023-03-24T09:34:05Z

DragonSphere:

TPWM compression

2023-03-24T09:32:59Z

DragonSphere: Created page with "TPWM stands for Turbo Packer by Wolfgang Meyerle. This relatively unknown compression tool was released for the Amiga and Atari ST in the late 1980s and was used by BlueByte (..."

TPWM stands for Turbo Packer by Wolfgang Meyerle. This relatively unknown compression tool was released for the Amiga and Atari ST in the late 1980s and was used by BlueByte (Ubisoft) to compress the data files of many of their games from the early 1990s.
Files compressed with this packer can be easily recognized by an ID string "TPWM" directly at the beginning of the file. This ID string is followed by four bytes, which is the size of the unpacked data and then the packed data itself. The size of the packed data thus results from the file size - 8;
The packing algorithm shortens repeating byte sequences with a length between 3 and 18 bytes to 2 bytes. In these 2 bytes, the length of the sequence and the relative offset (max. 0xFFF bytes) is recorded. Longer sequences are accordingly composed of several such bytes with unpacking information. All other byte sequences remain unchanged.
In order to determine during unpacking where in the packed file an unpacking information is located instead of normal data bytes, the packer inserts an extra byte whose bits for the next 8 bytes indicate whether they are data bytes or unpacking information.

Here is an example of an unpack routine as C code:

<syntaxhighlight lang="c">

int Unpack_TPWM()
{
unsigned char b1,b2;
unsigned short packbyte;
int bit, i;
unsigned long input_offset;
unsigned long output_offset;
unsigned int distance;
unsigned int length;

output_offset = 0;
input_offset = 0;

while ((input_offset < pack_size) && (output_offset < unpacked_size))
{
packbyte = GetInputByte(input_offset);
input_offset++;

for (bit = 0; bit <= 7; bit++)
{
if ((output_offset >= unpacked_size) || (input_offset >= packed_size)) break;
packbyte *= 2;

if (packbyte > 0xFF)
{
packbyte &= 0x00FF;
b1 = Input_Buffer[input_offset];

input_offset++;
if (input_offset > packed_size) break;

length = (b1 & 0x000F)+2;

b2 = Input_Buffer[input_offset];
input_offset++;

distance = b2 | ((b1 << 4) & 0x0F00);

for (i = 0; i <= length; i++)
{
Output_Buffer[output_offset] = Output_Buffer[output_offset-distance];
output_offset++;
if (output_offset >= unpacked_size) break;
}
}
else
{
Output_Buffer[output_offset] = Input_Buffer[input_offset];
input_offset++;
output_offset++;
}
}
}

if (output_offset < unpacked_size)
return -1;
else
return 0;
}

</syntaxhighlight >

2023-03-22T09:13:21Z

DragonSphere:

Battle Isle / History Line map format

2023-03-21T15:33:08Z

DragonSphere:

Battle Isle / History Line map format

2023-03-21T14:57:16Z

DragonSphere:

{{NeedMoreInfo}}
{{Map Infobox
| Type = 2D tile-based
| Layers = 1
| Tile size = 24×24
| Viewport = 10×8
| Games =
{{Game|History Line 1914-1918}}
}}

History Line 1914-1918 (and Battle Isle) battlefields are based on 24x24 pixel hexagon fields. The game uses split-screen, so both players only see a 10x8 hex field section, which is scrolled across the map.
The maps are stored in the form of *.fin and *.shp files in the MAP subdirectory of the game. The *.fin files contain the information about the individual hex fields (terrain and units), the *.shp files about the contents of buildings (resources, contained units, belonging to a side, etc.).

== *.fin File Format ==
The *.fin files start with two word in Motorola byte order (big-endian), indicating the size of the map in hex fields.

{|class="wikitable"
! Data type !! Name !! Description
|-
| [[UINT16BE]] || Max X || Width of the map in hex fields (+1)
|-
| [[UINT16BE]] || Max Y || Height of the map in hex fields (+1)
|-
|}

Two bytes follow for each hex field of the map. The first byte contains the number of the terrain graphic, the second one the number of a unit standing on the field. If there is no unit on the field, the value of the second byte is 0xFF.
The map is stored in rows. At the end of each line, History Line 1914-1918 stores an additional field with the values 0xAF and 0xFF and at the end follows a complete additional row with these values, but they are not displayed in the game.
Except for this additional row/column, the maps in Battle Isle are stored identically.

{|class="wikitable"
! Data type !! Name !! Description
|-
| [[UINT8]] || Ground || Terrain of this hex field
|-
| [[UINT8]] || Unit || Military unit on this hex field
|-
|}

Battle Isle / History Line map format

2023-03-21T14:56:42Z

DragonSphere: Created page with "{{NeedMoreInfo}} {{Map Infobox | Type = 2D tile-based | Layers = 1 | Tile size = 24×24 | Viewport = 10×8 | Games = {{Game|History Line 1914-1918}} }} His..."

{{NeedMoreInfo}}
{{Map Infobox
| Type = 2D tile-based
| Layers = 1
| Tile size = 24×24
| Viewport = 10×8
| Games =
{{Game|History Line 1914-1918}}
}}

History Line 1914-1918 (and Battle Isle) battlefields are based on 24x24 pixel hexagon fields. The game uses split-screen, so both players only see a 10x8 hex field section, which is scrolled across the map.
The maps are stored in the form of *.fin and *.shp files in the MAP subdirectory of the game. The *.fin files contain the information about the individual hex fields (terrain and units), the *.shp files about the contents of buildings (resources, contained units, belonging to a side, etc.).

== *.fin File Format ==
The *.fin files start with two word in Motorola byte order (big-endian), indicating the size of the map in hex fields.

{|class="wikitable"
! Data type !! Name !! Description
|-
| [[UINT16BE]] || Max X || Width of the map in hex fields (+1)
|-
| [[UINT16BE]] || Max Y || Height of the map in hex fields (+1)
|-
|}

== Tile Data ==
Two bytes follow for each hex field of the map. The first byte contains the number of the terrain graphic, the second one the number of a unit standing on the field. If there is no unit on the field, the value of the second byte is 0xFF.
The map is stored in rows. At the end of each line, History Line 1914-1918 stores an additional field with the values 0xAF and 0xFF and at the end follows a complete additional row with these values, but they are not displayed in the game.
Except for this additional row/column, the maps in Battle Isle are stored identically.

{|class="wikitable"
! Data type !! Name !! Description
|-
| [[UINT8]] || Ground || Terrain of this hex field
|-
| [[UINT8]] || Unit || Military unit on this hex field
|-
|}

History Line 1914-1918

2023-03-21T14:10:20Z

DragonSphere: Created page with "{{Game Infobox | Levels = Yes | Tiles = | Fullscreen = Yes | Sound = No | Music = No | Text = No | Story = No | Interface = No }} History Line 1914-1918 is a turn-ba..."