Skip to content

HUDSystem

Location: client/include/systems/HUDSystem.hpp

Renders HUD text for score and lives. It reads shared gameplay data (ScoreComponent, LivesComponent) and client render data (TextComponent, TransformComponent), resolves fonts via FontManager, and draws SFML text on top of the scene.

Responsibilities

  • Format HUD strings:
  • Score: Score: <value>
  • Lives: Lives: <current>/<max>
  • Apply render settings from TextComponent:
  • fontId → resolve sf::Font in FontManager
  • characterSize, color, content
  • Position/scale/rotation from TransformComponent
  • Draw to the Window each frame.
  • Render simple life pips (small rectangles) beneath lives text.

Required Components

An entity must have: - TransformComponent — screen position/scale/rotation for the text. - TextComponent — font id, color, size, content, optional cached sf::Text.

Optional (mutually exclusive priority): - ScoreComponent — if present, HUD shows Score: value. - LivesComponent — if no score is present, HUD shows Lives: current/max and draws pips.

Layering: - Use LayerComponent with RenderLayer::HUD to ensure the HUD renders above game entities.

Update Flow

1) Iterate entities with TransformComponent + TextComponent. 2) Skip dead entities. 3) Compute text content from ScoreComponent or LivesComponent (score takes priority if both exist). 4) Resolve font via FontManager::get(fontId); skip drawing if missing. 5) Create or update sf::Text: - setFont, setString(content), setCharacterSize, setFillColor. - Apply transform: position, scale, rotation from TransformComponent. 6) window.draw(sf::Text). 7) If LivesComponent present, draw pips rectangles under the text to visualize remaining lives.

Usage Example

// Load font once
fontManager.load("main", "client/assets/fonts/MainFont.ttf");

// Score HUD entity
EntityId scoreHud = registry.createEntity();
registry.emplace<TransformComponent>(scoreHud, TransformComponent::create(20.f, 20.f));
registry.emplace<LayerComponent>(scoreHud, LayerComponent::create(RenderLayer::HUD));
registry.emplace<TextComponent>(scoreHud, TextComponent::create("main", 24, sf::Color::White));
registry.emplace<ScoreComponent>(scoreHud, ScoreComponent::create(0));

// Lives HUD entity
EntityId livesHud = registry.createEntity();
registry.emplace<TransformComponent>(livesHud, TransformComponent::create(20.f, 60.f));
registry.emplace<LayerComponent>(livesHud, LayerComponent::create(RenderLayer::HUD));
registry.emplace<TextComponent>(livesHud, TextComponent::create("main", 24, sf::Color::White));
registry.emplace<LivesComponent>(livesHud, LivesComponent::create(3, 3));

// Register system after render
gameLoop.addSystem(std::make_shared<RenderSystem>(window));
gameLoop.addSystem(std::make_shared<HUDSystem>(window, fontManager));

Notes & Best Practices

  • Ensure the font is loaded before drawing; missing fonts skip drawing but keep content updated.
  • Keep HUD entities out of replication if they are client-only displays.
  • Score takes precedence when both score and lives components are present on the same entity; separate entities are recommended for clarity.
  • Adjust pip size/spacing in HUDSystem if you want a different visual style.