Hud

The in-game heads-up display: a port of the original's bottom-of-screen information bar, drawn last over the 3D scene.

Location

Purpose

Hud draws what the player sees on top of the world during Play: lives, held keys, the treasure counter, glue shots, dynamite, decoys, the breath and power gauges, the training hint banner, the game-speed indicator, the "fly to the HUD" animation of a picked-up item, and the optional compass. Its layout reproduces the original's Decor::DrawInfo in the original's 640 x 480 reference space. The space is scaled uniformly by viewport height / 480 and centred horizontally, so the proportions are the same at any window size.

The HUD is drawn as textured quads through a BasicEffect with an orthographic pixel projection, not through SpriteBatch. That keeps the draw order explicit: quads submitted last are drawn on top on every renderer. Text uses Content/icons/text.png with the original's proportional glyph widths (TextMetrics, since 2026-10-25).

The class has no gameplay state of its own: the host passes every value to Draw each frame.

Collaborators

Uses

• Six sprite sheets from Content/icons/: blupi.png, element.png, text.png, pad.png, jauge.png, button.png, each in its 2x version when 2x textures are in use (TextureScale.hpp). If one is missing, the HUD disables itself.
• TextMetrics for text layout, ObjectiveCompassArrows (ObjectiveHint.hpp) for the compass.

Used by

• GalaxyEggbertGame: LoadContent in GalaxyEggbertGameLoad.cpp; DrawUnderwaterTint and Draw in DrawOverlay (GalaxyEggbertGameDraw.cpp). The values come from InteractionSystem (lives, keys, treasures, ammunition, the pickup flight, the compass target) and BlupiController (gauges, animation icon, facing).
• Hud::ProjectWorldToHudSpace is also used by the host (death and pickup animations) and by the editor (WorldEditorUpdate.cpp, to pick the object nearest the screen centre).

Key members

The complete public API of Hud.hpp is small; this is all of it.

void Draw(GraphicsDevice& device, int viewportW, int viewportH,
          int lives, bool key1, bool key2, bool key3,
          int treasures, int totalTreasures, bool showTreasureCounter,
          int bullets, int dynamite, int perso,
          bool waterGaugeVisible, int waterGaugeLevel,
          bool powerGaugeVisible, int powerGaugeLevel,
          std::string_view trainingHint,
          const char* overlayMessage,
          int animIcon, bool animIconUsesElementSheet,
          bool voyageActive, int voyageIconId, bool voyageIsButtonChannel,
          bool voyageIsBlupiChannel,
          float voyageX, float voyageY,
          GalaxyEggbert::Def::GameSpeed gameSpeed, float animOpacity = 1.0f,
          std::optional<ObjectiveHint> objective = std::nullopt,
          bool rightTouchControls = false, float blupiYaw = 0);

What Draw shows

Positions are in the 640 x 480 reference space, taken from the constants in Hud.cpp.

overlayMessage would draw one large centred message instead of the HUD. As of 2026-11-10 the host's PhaseOverlayMessage() returns nullptr for every phase, because Pause, Win and Lost have real screens drawn by InputPad.

How it is used

The host calls Draw from GalaxyEggbertGame::DrawOverlay only when the current phase has no full screen of its own (Pause, Win, Lost, Setup, Resume, Wait, Init and Editor do), and after it has turned depth testing off. An excerpt from src/GalaxyEggbertCNA/GalaxyEggbertGameDraw.cpp:

const int hudMission = worldRuntime_.GetMissionNumber();
const bool showTreasureCounter = hudMission != 1 && hudMission % 10 != 0;
hud_.Draw(device, viewport.getWidthProperty(), viewport.getHeightProperty(),
          interaction_.Lives(),
          interaction_.Key1Count() > 0, interaction_.Key2Count() > 0,
          interaction_.Key3Count() > 0,
          interaction_.TreasuresCollected(), interaction_.TotalTreasures(), showTreasureCounter,
          interaction_.BulletCount(), interaction_.DynamiteCount(), interaction_.PersoCount(),
          blupi_.IsNage(), blupi_.GetWaterGaugeLevel(),
          ...
          cheatCompass_ && GalaxyEggbert::Game::kCheatsEnabled
              ? InteractionSystem::NearestObjective(
                  worldRuntime_, blupi_.GetX(), blupi_.GetY(), blupi_.GetZ()) : std::nullopt,
          tickInput_.touchControlsEnabled, blupi_.GetYaw());

Rules and invariants

• Draw the HUD last in the frame, with depth testing disabled; it sets its own blend states and leaves Opaque set.
• Layout is in the 640 x 480 reference space only; never place HUD items in window pixels.
• The HUD is presentation: it reads values and changes nothing in the simulation, so it cannot affect determinism, golden traces or autoplay results.
• The compass is the direct 3D distance to the nearest active chest, or, when none is left, to the nearest exit (an object whose registry entry has levelExit); it is not a route length.

Tests

There is no dedicated Hud verifier. Coverage comes from:

• VerifyInteractionSystem (tools/VerifyInteractionSystem.cpp, links Hud.cpp): checks Hud::ProjectWorldToHudSpace, the compass target (NearestObjective) and its arrows (ObjectiveCompassArrows).
• The golden frames in tests/golden/ capture whole Play frames of world 999, HUD included (tools/verify_golden_frames.sh; needs a display, not part of ctest).
• The editor verifiers link Hud.cpp because the editor uses ProjectWorldToHudSpace.

Related pages

• InputPad: menus, touch pad, cheats list and help overlay
• InteractionSystem, BlupiController: where the HUD's values come from
• GalaxyEggbertGame: the draw order
• Gameplay, Cheats & Diagnostics
• Rendering, Game Loop