Campaign eckmuhl Map Files Unleashed

note : this page is an update from J.Pumphrey, Al Amos, G.Gorsuch "engineering section" page
It is made for educationnal purpose only.

Updated, August, 9th, 2002

1. Introduction

The HPS® map file "*.map" is a set of instructions to the campaign eckmuhl® main program on how to build the map in its working memory.
The file is a pure text document and can easily be read using a text editor. It is almost the same as used in older Talonsoft® games, showing a direct filiation between these two games.
In the existing Napoleonic engines, this memory model of the map is entirely separate from its visual representations, which are bitmaps files.
The "*.map" files are located in the main folder of the game.
The various bitmap files are located in the /map folder of the game.

From version 1.02 and onwards, there is a subfolder in /map folder : /map/snow where terrain tiles are located to be used in snow weather condition. The instruction to display snow terrain tiles is not given in the "*.map" file, but in the scenario files. It should be dealt with them later.

The map file contains a short 3-line header followed by up to 15 blocks of text. The first block gives terrain type, the second elevation, the next 12 hexside features, and the last place-names.

Reference is made to the BGW Hougoumont map from time to time as an example. Maps are very similar between games.

2. The Header

The header is the first three lines of text.

2.1 First line

The first line contains just one character; so far, this is  a "1" in HPS eckmuhl.

2.2 Second line

The second line contains two numbers separated by a space. The first is the number of columns, and the second the number of rows. Thus in the Hougoumont map, where the bottom right hex is (22,16) numbered from 0, the values in the second line are "23 17".

2.3 Third line

The third line contains four numbers separated by spaces.

The first number is the base elevation, or height above sea level in metres of the starting elevation (value 0 in the elevation block, which I will deal with below). In Hougoumont, this is 70 so the lowest elevation level is 70m above sea level.

The second number is the height in metres of each level of elevation. In the Hougoumont map it is 10m. The program multiplies this by the value in the elevation block and adds it to the base elevation to get the result which it displays.

The third number is the direction of North, coded anti-clockwise as follows:

The fourth number is a checksum value, which is calculated by totalling certain of the values in the map file. See below for a detailed account of calculating the checksum.

In HPS Jena, a fourth number is introduced, either 0 or 1. We have no idea what is the reason of that's number presence.
If you know its use, just tell me about it.

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3. Block 1: Terrain Types

This block consists of a character for each hex representing terrain type, or more precisely features which affect the hex as such, and not the hex sides. Where a clear hex is present, the character used is a space. You can see this by selecting all the text in the block. In Hougoumont, you will see that a matrix of 23x17 characters is filled, even though most of them are spaces and thus invisible. This matrix must be maintained at all times if editing manually.

The character codes for the terrain types, and their checksum values, are as follows:

(Each character code leads to a .bmp terrain tile file as is explained in .8 HERE.)

4. Block 2: Elevations

This block is always fully filled with values representing levels of elevation with 0 as the lowest level relative to the map. After the numbers 0-9, values continue with lower case letters of the alphabet, at least to "f". I have not yet confirmed it, but possibly the entire alphabet gives ever higher elevation levels.

5. Blocks 3-14: Hexside Features

The next 12 blocks give hexside information broken down by type. All other data, apart from that dealt with above and placenames, is hexside data.

Each of these blocks 3-14 is headed, on a line of its own, by either a "0" or a "1". If by a "0", then no data follows; if by a "1", then data follows and the full matrix must be filled.

This data is in the form of a series of characters representing North-West, North, etc, hexsides and any combination of them. Here also spaces represent hexes with no marked sides.

Thus roads as well as hedges or walls are treated purely as hexsides by the program. A road starting in the middle of a hex and passing through the South-East hexside has exactly the same character code and checksum value as a hedge along the South-East hexside. Note that a road passing from the North-West to the South-East would have the same code as two hedges, one to the North-West, and one to the South-East. And note further that a hedge requires to be defined also in the adjoining hex, as do most similar types such as walls and streams.

These various character codes which have a purely directional meaning by themselves, gain their terrain meaning from whichever block they appear in, as follows:

* This is of course a Civil War feature, that is not used in campaign eckmuhl, but present anyway in map files.

This data is laid out in a table with an understandable pattern. One starts with North, then North-East, then combines the two; the 4th value is South-East, to which one then adds the pattern of the first 3, and so on.

The checksum values follow this pattern starting at 1. This progression gives, for the six points of the hex "compass", the following checksum values:

A checksum value for any given combination of hexsides can be calculated by adding together these base values.

Each combination in the table is assigned a text character, starting with various special characters and passing through the numbers 1-9 and all (capital) letters of the alphabet. Programmers will recognize it as the ASCII sequence starting at hex (-adecimal... let's not get confused!) 21, and ending at 5F.

Here follows a complete list of these, showing the character used, the hexsides, and the checksum value. (The sequence I use is always clockwise from North -- No;NE;SE;So;SW;NW -- so a browser search can be used to find a particular combination):

(I have not rechecked these values very well for this version of the document.)

6. Block 15: Place Names

The place names block has one name entry per line of text. The line consists of five numeric values and the name itself. The five values are column, row, font size, justification and color.

6.1 Column & Row

The values here have decimal places, and these indicate the precise starting (or ending--depending on justification) position of the text within the hex.

6.2 Font size

These are apparently 1-4.

6.3 Justification

This, together with the decimal column/row positioning, allows for very exact placing of names and for proper placing on the far right of the map.

Values are:

6.4 Color

Color values are:

 

So in the Hougoumont file, the line :
2.5 0.5 1 1 0 Chemin de Genappe à Braine l'Alleud

means text "Chemin de Genappe à Braine l'Alleud" occurs in the center of hex (2,0), with font size 1, justified center, and in black.

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7. Calculating the Checksum

Theoretically a completely blank map file has a checksum value of zero. A map file with one column and one row, with a clear terrain type (space), has a checksum of 3. Thereafter each addition of 1 space to the row (ie. adding a new column) adds 2 to the total, but only for the first row; just 1 is added for each space in the subsequent rows. The same applies starting with one column and adding rows: initially 2 is added for each new row, but only 1 for each space in the subsequent columns.

The formula is in fact:

(columns.rows) + columns + rows

So, for the Hougoumont matrix of 23.17, we get:

(23.17) + 23 + 17 = 431

Once this base has been calculated, the non-clear terrain character values are accumumulated as indicated in the table above.

Note that inserting a non-listed character as a terrain type subtracts 1 from the checksum instead of incrementing it. The map loads, but displays this hex as "Blocked" with its image greyed-out, an interesting quirk...

The values in the elevations block do not affect the checksum. Neither does any data in the place-names block.

Only in campaign Eckmuhl you have to add 1545 to the map checksum value.
Other games has other values, the list is not complete :
Russian campaign adds 2587
Campaign Waterloo adds 1677
Campaign Wagram adds 1439
Campaign Corinth adds 1559

Spaces in the hexside blocks do not affect the checksum. Other hexside character values are accumulated as indicated in the table above.

The checksum can be calculated either manually, or using a checksum calculator utility. This will be explained in a later 'making maps' page.

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 8. Displaying the terrain

Each character code for terrain in the first block is read by the program as an instruction to display a specific part (icon) of a bitmap file.

Block 1 character codes "e" - "b" - "c" - "v"
leads to 3Dfeatures100.bmp file
3Dfeatures100.bmp file is a bitmap file whose dimensions are : 900 pixels width x 700 pixels height.
3Dfeatures50.bmp file is the same as above, only halved in dimensions, to use when you zoom out the map.
We call this file : terrain tile.
It is divided by the program in 6 columns and 5 lines, forming 30 icons, each 150 x 140 pixels
arranged in the following patern :

FIELD	FIELD	FIELD	FIELD	FIELD	FIELD
BUILDING	BUILDING	BUILDING	BUILDING	BUILDING	BUILDING
CASTLE	CASTLE	CASTLE	CASTLE	CASTLE	CASTLE
VILLAGE	VILLAGE	VILLAGE	VILLAGE	VILLAGE	VILLAGE
VILLAGE	VILLAGE	VILLAGE	VILLAGE	VILLAGE	VILLAGE

character code "e" tells the programm to display on the map, at the corresponding column/row hex, one of the six "FIELD" icons. The program chooses one of the field icons randomly.

character code "b" tells the programm to display, with the same method, one of the six "BUILDING" icons.

character code "c" tells the programm to display, with the same method, one of the six "CASTLE" icons.

character code "v" tells the programm to display, with the same method, one of the six "VILLAGE" icons.
Some of the village icons are made for hexes crossed by a road, where houses are more scattered.

The background colour of this terrain tile is transparent. The colour of the pixel at position x = 0, y =0 determines which colour will be used by the program as "transparent" for this file.

Block 1 character codes "o" - "f"
leads to 3Dtrees100.bmp files
3Dtrees100.bmp file is a bitmap file whose dimensions are : 900 pixels width x 564 pixels height.
3Dtrees50.bmp file is the same as above, only halved in dimensions, to use when you zoom out the map.
It is divided by the program in 6 columns and 6 lines, forming 36 icons, each 150 x 94 pixels
arranged in the following patern :

FOREST	FOREST	FOREST	FOREST	FOREST	FOREST
ORCHARD	ORCHARD	ORCHARD	ORCHARD	ORCHARD	ORCHARD
FOREST	FOREST	FOREST	FOREST	FOREST	FOREST
FOREST	FOREST	FOREST	FOREST	FOREST	FOREST
FOREST	FOREST	FOREST	FOREST	FOREST	FOREST
ORCHARD	ORCHARD	ORCHARD	ORCHARD	ORCHARD	ORCHARD

character code "f" tells the programm to display on the map, at the corresponding column/row hex, one of the six "FOREST" icons. The program chooses one of the forest icons randomly.

character code "o" tells the programm to display, with the same method, one of the six "ORCHARD" icons.
Some of the icons are made for hexes crossed by a road, where trees are more scattered.

The background colour of this terrain tile is transparent. The colour of the pixel at position x = 0, y =0 determines which colour will be used by the program as "transparent" for this file.

Block 1 character codes "r" - "s"
AND
Block 2 character codes for elevation levels
leads to 3Dground100.bmp files
3Dground100.bmp file is a bitmap file whose dimensions are : 900 pixels width x 1598 pixels height.
3Dground50.bmp file is the same as above, only halved in dimensions, to use when you zoom out the map.
This file is used to display elevation levels as well as rough terrain and marsh terrain.
It also includes shadowed hexes with various use by the programm : display hexes visible by a unit, blocked hexes, etc.
It is divided by the program in 6 columns and 17 lines, forming 102 icons, each 150 x 94 pixels
arranged in the following patern :

The first 14 lines are used to display elevation levels from the lowest (1st line) to the highest (14th line).

LOWEST	LOWEST	LOWEST	LOWEST	LOWEST	LOWEST
HIGHEST	HIGHEST	HIGHEST	HIGHEST	HIGHEST	HIGHEST
MARSH	MARSH	MARSH	MARSH	MARSH	MARSH
ROUGH	ROUGH	ROUGH	ROUGH	ROUGH	ROUGH
BLOCKED	VISIBLE	?

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OTHER TERRAIN TILES :

NOTE : files dimension is not given here every time, but can be calculated very easily

3DWater100.bmp : used to display water hexes
dimensions : ___ width * ___ height pixels / __ columns, __ rows / __ icons each ___ * ___ pixel

3Dstream100.bmp : used to display stream hexsides
dimensions : ___ width * ___ height pixels / __ columns, __ rows / __ icons each ___ * ___ pixel

3Dcreeks100.bmp : used to display creeks (rivers) hexsides
dimensions : ___ width * ___ height pixels / __ columns, __ rows / __ icons each ___ * ___ pixel

3Dblocked100.bmp : used to display : walls, high walls, hedges, embankments hexsides
dimensions : ___ width * ___ height pixels / __ columns, __ rows / __ icons each ___ * ___ pixel

3Dmain100.bmp : used to display main roads (aka pikes)
dimensions : ___ width * ___ height pixels / __ columns, __ rows / __ icons each ___ * ___ pixel

3Dpaths100.bmp : used to display paths (of course)
dimensions : ___ width * ___ height pixels / __ columns, __ rows / __ icons each ___ * ___ pixel

3Droads100.bmp : used to display roads (minor roads)
dimensions : ___ width * ___ height pixels / __ columns, __ rows / __ icons each ___ * ___ pixel

3Dfords100.bmp : used to display fords
dimensions : ___ width * ___ height pixels / __ columns, __ rows / __ icons each ___ * ___ pixel

3DHexedges100.bmp : used to insert between some hexes so the map don t look to geometric
dimensions : 450 width * 132 height pixels / 6 columns, 2 rows / 12 icons each 75 * 66 pixel

3Dbridge100.bmp : used to display bridge. Line 1 show the bridge undamaged, line 2 damaged bridges
dimensions : 408 width * 156 height pixels / 3 columns, 2 rows / 6 icons each 136 * 78 pixel

Each of this tile has a "*50.bmp" counterpart for zoom out function.

Each terrain tile has a 2D counterpart to use in 2D view.