Setup

Engine Setup

This page covers setup of the engine prior to making the game

Remarks

The engine is still under development and this page is subject to change.

TODO: includes

Game Setup

Prior to initializing the engine, game functionality may be designed. This includes game variables, constants, functions, or class instantiations.

Only game functionality that is independant of engine functionality may be performed here.

void Welcome() {
    std::cout << "Welcome to the game!" << '\n';
    std::cout << "This game is a fighting game..." << '\n';
    // ...
}
 
int main() {
 
    const std::string GAME_NAME = "Enemy fighter";
    const int GAME_VERSION = 4;
 
    const int NUM_ENEMIES = 3;
    
    Welcome();
 
 
    // Initialize engine
    // ...
 
    return 0;
}

A welcome message function, as well as game constants are defined prior to initializing the engine

Initializing the engine

The global engine object must be initialized using Get(), prior to any engine operations. Engine subobjects must also be loaded using LoadSubobjects().

PotatoEngine& engine = PotatoEngine::Get()
engine.LoadSubobjects();

Initializes the engine object and returns a PotatoEngine&. It is stored in the engine object. LoadSubobjects() is called.

Ensure PotatoEngine::Get() is called before anything else (see Game Setup for more info)

Instance Settings

Setup engine constants and settings using GameInstance.

GameInstance* instance = GameInstance::get();
 
instance->FRAMES_PER_SECOND = 24.f;
instance->MS_REPEAT_THRESHOLD = 195;

Gets the game instance and sets the FPS and repeat threshold values

Level Setup

Load the persistent level. Fetch dynamic actors (TODO) and load static actors into world using LoadStaticActors().
A valid save file must be placed under Saves/.

PersistentLevel level("mySave.json"); // "Saves/mySave.json" exists!
 
level.LoadStaticActors();

Creates a level object associated with "mySave.json" and loads static actors.

UI Setup

Add widgets and other UI elements using the HUDController.

// engine declared
 
IHUDController* HUDController = engine.GetHUDController();
 
HealthBarWidget* healthBar = HUDController->AddWidget<HealthBarWidget>("healthbar");
MapWidget* minimap = HUDController->AddWidget<MapWidget>("minimap");
InventoryWidget* inventoryDisplay = HUDController->AddWidget<InventoryWidget>("inventory");

Adds health bar, minimap, and inventory widgets to the HUD. Note that these are placeholder classes not implemented by the engine.

Other Game Setup

Other game settings that involve engine functionality may be performed here. This includes player setup or player controller settings.

// instance declared
 
PlayerController* playerController = instance->GetPlayerController();
Player* player = playerController->GetPlayer();
 
player->Texture = 'P';
player->SetVisibility(false);

Sets the player texture to 'P' and hides the actor (prior to game start).

Game Loop

Start the main game loop using BeginPlay() and handle loop exit using Resolve().

After starting the game loop, Resolve() will only be called after the loop has completed and the engine is shutting down.

// engine declared
 
engine.BeginPlay();
 
engine.Resolve();

Calls BeginPlay() and Resolve() sequentially

Ensure Resolve() is called prior to post-game functionality. This is vital to ensure proper memory cleanup for engine internals.

Exit

Complete post-game operations and exit program.

Only game functionality that is independant of engine functionality may be performed here.

// engine declared
 
void Goodbye() {
    std::cout << "Thanks for playing!";
}
 
int main() {
    
    // ...
    engine.Resolve()
 
    Goodbye();
 
    return 0;
}

After resolving engine, a goodbye message is displayed and the program returns

Example

This is a full example of a prototype game main function

void Welcome() {
    std::cout << "Welcome to Enemy fighter!" << '\n';
    std::cout << "This game was developed by bob." << '\n';
    std::cout << "Press enter to start...";
    std::cin.get();
}
void Goodbye() {
    std::cout << "Thanks for playing Enemy Fighter!";
    std::cout << "Support me at bob.com!";
}
 
int main() {
 
    const std::string GAME_NAME = "Enemy fighter";
    const int GAME_VERSION = 4;
 
    const int NUM_ENEMIES = 3;
    
    Welcome();
 
    PotatoEngine& engine = PotatoEngine::Get()
    engine.LoadSubobjects();
 
    GameInstance* instance = GameInstance::get();
 
    instance->FRAMES_PER_SECOND = 24.f;
    instance->MS_REPEAT_THRESHOLD = 195;
 
    PersistentLevel level("mySave.json"); 
    level.LoadStaticActors();
 
    IHUDController* HUDController = engine.GetHUDController();
 
    HealthBarWidget* healthBar = HUDController->AddWidget<HealthBarWidget>("healthbar");
    MapWidget* minimap = HUDController->AddWidget<MapWidget>("minimap");
    InventoryWidget* inventoryDisplay = HUDController->AddWidget<InventoryWidget>("inventory");
 
    PlayerController* playerController = instance->GetPlayerController();
    Player* player = playerController->GetPlayer();
 
    player->Texture = 'P';
 
    // GAME START
    engine.BeginPlay();
 
    engine.Resolve();
    // GAME END
 
    Goodbye();
 
    return 0;
}