Services Module

Dook is an inherently service based system as mentioned in Working with Services, these classes are how.

Service Locator

class ServiceLocator

Get services safely.

Public Static Functions

static void provide(std::unique_ptr<LevelService> service)

Register a level service.

Parameters:: service – Level service unique ptr.

static void provide(std::unique_ptr<GraphicsService> service)

Register a graphics service.

Parameters:: service – Graphics service to register.

static void provide(std::unique_ptr<LoggerService> service)

Register a logger service.

Parameters:: service – Logger service to register.

static void provide(std::unique_ptr<InputService> service)

Register an input service.

Parameters:: service – Input Service to register.

static LevelService &level()

Get the level service.

Returns:: LevelService& Reference to level service.

static GraphicsService &graphics()

Get the registered graphics service.

Returns:: GraphicsService& Reference to graphics server.

static LoggerService &logger()

Get the registered logger.

Returns:: LoggerService& Reference to the logger.

static InputService &input()

Get the registered input service.

Returns:: InputService& Regerence to the input processor service.

Abstract & Null Services

These services are the ones that need to be extended with concrete implementations before being used, each has a null variant which is by default registered to the service locator.

class GraphicsService

This service handles the drawing and rendering.

Subclassed by dook::NullGraphicsService, dook::SDLGraphicsService

Public Functions

inline GraphicsService(Camera viewport)

Construct a new Graphics Service object.

Constructs the window object as well.

Parameters:: viewport – the size of the “screen” and its offset in the total texture.

virtual ~GraphicsService() = default

Destroy the Graphics Service object.

Deallocate the window resources as well.

void tick(): Re-draw the screen.

virtual std::unique_ptr<Texture> load_texture(std::string filename, const Rect &draw_rect) = 0

Load a texture into the memory with the given draw rect.

Parameters:

filename – Path to the texture.
draw_rect – Draw rectangle information.

Returns:

std::unique_ptr<Texture> Unique ptr to the texture.

virtual std::unique_ptr<Texture> load_texture(std::string filename) = 0

Load a texture into memory from its filename.

Parameters:: filename – Filename to load from.
Returns:: std::unique_ptr<Texture> Unique ptr to the texture.

class InputService

This service user input.

Fun fact, I planned to implement this in co_await, co_yield. This plan was sadly destroyed when I see the boilerplate to do so, and no, I am NOT adding a library for this purpose.

Subclassed by dook::NullInputService, dook::SDLInputService

Public Functions

virtual std::unique_ptr<Command> tick() = 0

Process the next user input.

Returns:: A unique ptr that either includes a user input or nullptr if not available.
Returns:: false otherwise.

virtual bool quit() = 0

Check if the user have inputted a keycharacter that causes the game to be quit.

Returns:: true When user have requested game to quit.
Returns:: false Otherwise.

class LevelService

This service handles level mainloops.

Loads levels, and keeps track of the current level.

Subclassed by dook::NullLevelService

Public Functions

virtual bool load_level(std::string name) = 0

Load the level with the given name.

Parameters:: name – Name of the level.
Returns:: true If the load is sucessful.
Returns:: false otherwise.

void tick(): Tick every single object, make them take action, etc.

class LoggerService

Used to log events.

Subclassed by dook::CommonLoggerService, dook::NullLoggerService

Public Functions

virtual void log(std::string message) = 0

Log a message to… somewhere.

Parameters:: message –

virtual void error(std::string message) = 0

Log an error to… somewhere.

Parameters:: message –

class NullGraphicsService : public dook::GraphicsService : Noop graphics service.

class NullInputService : public dook::InputService : Null placeholder for input generation.

class NullLevelService : public dook::LevelService 

class NullLoggerService : public dook::LoggerService 

Common Services

Some services are so common accross various domains that, their concrete implementations are also written in the module.

class CommonLoggerService : public dook::LoggerService 

Public Functions

virtual void error(std::string message) override

Log an error to… somewhere.

Parameters:: message –

virtual void log(std::string message) override

Log a message to… somewhere.

Parameters:: message –