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Draw Text System

Source: client/engine/systems/SystemsFunctions/Render/DrawTextSystem.cpp

Purpose: Render entities with a Text component while applying hierarchical transforms (position, rotation, scale) and respecting draw order via z_index.

Components used:

  • Transform
  • Text

Behavior​

  • Load the font from Text::fontPath on first pass (InitializeText).
  • Compute the text origin via GetOffsetFromTransform to align with the Transform origin.
  • Apply local offsets (offset), parent hierarchy transforms, and local rotation.
  • Apply cumulative scale (CalculateCumulativeScale) and adjust opacity via Text::opacity.
  • Sort entities by z_index before drawing to guarantee order.

Main signature​

void DrawTextRenderSystem(
    Eng::registry &reg,
    GameWorld &game_world,
    Eng::sparse_array<Com::Transform> const &transforms,
    Eng::sparse_array<Com::Text> &texts);

Notes​

  • InitializeText sets the text size to characterSize * 10 then applies cumulative scale divided by 10 to stay consistent with sprites.
  • If font loading fails, an error is logged to std::cerr but is_loaded flips to true to avoid endless retries.
  • The offset field lets you locally shift text relative to the Transform without changing hierarchy.