Chapter 2. Creating a KsirK skin

Table of Contents

KsirK is fully skinable. For who have graphic capabilities, creating a new skin is as simple as copying an existing one, editing or changing the graphics and updating the data in a .desktop configuration file, which is done using the KsirK Skin Editor. A last step is to edit the file describing what to install.

All examples (text and images) are taken from the default skin of KsirK.

Structure of folders and files

Data/ : Data used by the program to handle the images of the skin.
- CMakeLists.txt : Describes what to install.
- onu.desktop : Main file for the description of the skin. See its description below.
Images/ : The images of the skin (map, sprites, etc.)
- CMakeLists.txt : Describes what to install.
- pool.svg : The map and all the sprites used in this skin.
- map-mask.png : The image allowing the program to find which country the mouse is over during the game (see below).
- *.png : The other images here are buttons images.
CMakeLists.txt : Describes what to install.
Sounds/ : Sound files for the skin.

The Data folder

This folder contains only one file, world.desktop. This file is a description of the content of the skin. It is used to describe the organization of the world and how to display it. You don't have to fill it manualy as it will be handled by the KsirK Skin Editor. But, for the sake of completeness, we will now describe its structure.

An onu group contains a number of country entries, a number of nationality entries and lastly a number of continent entries. Then various groups contain the description of the different sprites, the description of the different countries, continents, nationalities and goals.

The following sections describe the content of each group.

The `onu` group

Table 2.1. The onu group entries

Entry name	Signification
`width`	The width of the skin's map.
`height`	The height of the skin's map.
`skinpath`	The path of the skin relative to the application data path (e.g. `skins/default`).
`nb-countries`	The number of countries (42 in the default skin). There should be the same number of country groups below.
`nb-nationalities`	The number of nationalities (6 in the default skin). There should be the same number of nationality groups below.
`nb-continents`	The number of continents (6 in the default skin). There should be the same number of continent groups below.
`pool`	The path and name of the pool file relative to the skin path (e.g. `Images/pool.svg`).
`map-mask`	The path and name of the map mask file relative to the skin path (e.g. `Images/map-mask.png`).
`format-version`	The version of the skin file format (2.0).
`name`	The display name of the skin.
`desc`	The long description of the skin.
`fighters-flag-y-diff`	The height difference between flags and cannons sprites.
`width-between-flag-and-fighter`	The number of pixels between the left most pixel of the flag and the right most pixel of the simple cannon (when not firing nor exploding).

The sprites description groups

Each type of sprite (flag, infantry, cavalry, cannon, firing cannon and exploding cannon) is defined by a group. Only some sprites have a width entry. This entry is used for relative positioning during animations: the cannons, firing or exploding should not “move” around the country's flag during fight.

Table 2.2. Sprite description group entries

Entry name	Signification
`width`	The reference width of the flag sprite frames.
`height`	The reference height of the flag sprite frames.
`frames`	The number of frames of the sprite.
`versions`	The number of versions of the flag sprites.

The countries description groups

Each country listed in the onu group, countries entry has its own group whose label is the country name. The table below lists the entries of these groups.

Table 2.3. Country entries

Entry name	Signification
`id`	The integer unique identification number of the country, must start at zero (0).
`name`	The displayed name of the country.
`<sprite>-point`	Each type of sprite (flag, infantry, etc.) in the country is displayed at a certain position defined by this entry made of two integers separated by a comma.
`neighbours`	The list of the ids of the neighbors of the current country.

The nationalities description groups

Each nationality listed in the onu group, nationalities entry has its own group whose label is the nationality name. The table below lists the entries of these groups.

Table 2.4. Nationality entries

Entry name	Signification
`name`	The name of the nationality (e.g. `Japan`).
`leader`	The name that will be proposed to the player choosing this nationality.
`flag`	The name of the country's flag sprite element in the `onu` SVG file.

The continents description groups

Each continent listed in the onu group, continents entry has its own group whose label is the continent name. The table below lists the entries of these groups.

Table 2.5. Continent entries

Entry name	Signification
`name`	The name of the continent (e.g. `Africa`).
`id`	The integer unique identification number of the continent.
`bonus`	The number of armies obtained at the end of the turn by the player owning all the countries of the continent.
`continent-countries`	The list of the ids of the countries inside the current continent.

The goals description groups

Each goal listed in the onu group, goals entry has its own group whose label is the goal name. The table below lists the entries of these groups.

Table 2.6. Goal entries

Entry name	Signification
`type`	The type of goal. Can be continents, countries or player.
`nbArmiesByCountry`	Set the minimal number of armies the player will have to put on each country.
`nbCountries`	Set the number of countries the player must possess.
`nbCountriesFallback`	For a player goal type, if the target player is killed by another one, this sets the number of countries the player will have to conquer instead.
`desc`	A full text description of the goal with appropriate placeholders (needs more doc here).
`continents`	The list of continents ids the player will have to conquer.

The Images folder

This folder contains the buttons specific to KsirK and the pool SVG file that contains the map and all sprites.

The `pool.svg` file

This SVG file contains the map and all the sprites of the game. Each element is named such that the game can select and render separately each of them.

In the default skin, the sprites are flags, infantry, cavalry and cannon. Infantry represents one army, five for cavalry and ten for cannons. Cannons are also used to display fighting armies. That's why there is three kinds of cannon sprites: normal static or moving cannon, firing one and exploding one.

Each sprite image is the concatenation of the various views of the object and for each view, its frames. Views are organized vertically and frames horizontally. Where to cut the image in individual frames is found by dividing the height of the image by the number of views and the width by the number of frames. These data are found in the onu.desktop file.

An example of a sprite image: cannon.png

For armies sprites, there is three different views, from top to bottom:

looking right
looking left and
facer

For flags, there is only one view. All sprites backgrounds should be set to transparent.

An example of a flag sprite image: italy.png

Table 2.7. The elements of the pool

Element name	Sample image	Signification
`map`		Map of the skins's world. Countries can have arbitrary shapes, but should be grouped in eye-recognizable continents, by location only or by color.
`italy`		The flag of the Italy nation. There is one such entry for each nation.
`infantry`		Icon representing one army.
`cavalry`		Icon representing five armies.
`cannon`		Icon representing ten armies.
`firing`		Icon representing armies during a fight.
`exploding`		Icon representing armies when losing a fight.
`alaska`		The shape of the Alaska country. This is used to highligth the country. There is one such shape for each country. Its color is not used. As such, the color is free.
`reddices`		The red dices used to show battles results.
`bluedices`		The blue dices used to show battles results.
`mark1`		This mark is added to fighting sprites to show the number of armies they represent, here 1. There is also a `mark2` and a `mark3` elements.

The `map-mask.png` file

This is a png file representing also the map of the skins's world, but with coded colors that allows one to identify uniquely each country. Countries must have at least the same shapes as the corresponding countries on the map.png file so that users can click anywhere in a viewable country and select the good one. Countries, like little islands as Indonesia in the default map can be greater than the equivalent in the map.png file to facilitate the selection of the country.

The blue component (in RGB model) of a country's color identifies the country: index 0 is country 0 in the onu.xml file, index 1 is country 1, etc. White (0xFFFFFF in RGB) identifies the absence of country (sees or, why not, no man's lands).

The buttons images

The filenames are hard-coded in the code, so they should not be modified. The table below shows all the buttons that should be provided.

Table 2.8. The buttons of the GUI

Image	Filename	Signification
	`newNetGame.png`	Tries to join a network game.
	`recycling.png`	After all players have put their armies, it is possible to modify the distributions (named recycling). This button asks to do such a redistribution.
	`recyclingFinished.png`	Chooses not to redistribute. All clients windows must have this button clicked to really end the distribution.
	`nextPlayer.png`	Ends the current player's turn and switch to the next one or to the next turn if the current player was the last one.
	`attackOne.png`	Chooses to start an attack with one army.
	`attackTwo.png`	Chooses to start an attack with two armies.
	`attackThree.png`	Chooses to start an attack with three armies.
	`defendOne.png`	Chooses to defend an attacked country with one army.
	`defendTwo.png`	Chooses to defend an attacked country with two armies.
	`moveArmies.png`	Chooses to start the moving of armies between two countries (last action in the turn).