draw HP bars below ships

docs/requirements.md

@@ -301,6 +301,7 @@ The screen is divided into three vertical sections:
 - REQ-UI-SCROLL: The player scrolls the view horizontally across the scrollable area by pressing A (scroll left) and D (scroll right).
 - REQ-UI-CONSTRUCTION-PROGRESS: Construction sites display the building's glyph centered on the footprint (same as an operational building). Below the glyph — or centered on the footprint if the building has no glyph — a construction progress percentage is shown (integer, e.g. `42%`), increasing from 0% to 100% as construction completes.
 - REQ-UI-PORT-GLYPH: Every output port of every building is indicated by a directional glyph drawn on the port's tile. The glyph is a `>` rotated to face the port's exit direction (`>` for East, `^` for North, `<` for West, `v` for South). It is drawn at the midpoint between the tile center and the tile edge that the port exits through (i.e. halfway from center toward the exit edge). The indicator is rendered for all building states: operational buildings, construction sites, and the builder-mode ghost. Buildings with multiple output ports (e.g. splitters) show one indicator per port.
+- REQ-UI-HP-BARS: All entities with HP — the HQ, player and enemy defence stations, and player and enemy ships — render an HP bar below them. The bar is always visible regardless of current HP. The bar's filled portion represents the fraction of current HP to maximum HP.
 - REQ-UI-NO-ZOOM: The view has a fixed zoom level; the player cannot zoom in or out.
 - REQ-UI-SCHEMATIC-TOAST: When a schematic is unlocked or leveled up (REQ-DEF-SCHEMATIC-DROP), a transient notification toast appears in the top-right corner of the game world view for 4 seconds and then fades out. `<Ship Name>` in the text below is the schematic's `ships.toml [ship.schematic].display_name`. Toast text:
   - **New unlock**: `Schematic unlocked: <Ship Name>`

src/balancing/ArenaView.cpp

@@ -310,10 +310,10 @@ void ArenaView::drawStations(QPainter& painter)
 void ArenaView::drawShips(QPainter& painter)
 {
     m_sim->admin().forEach<ShipIdentityComponent, PositionComponent, FacingComponent,
-                           FactionComponent>(
+                           FactionComponent, HealthComponent>(
         [&](entt::entity /*e*/, const ShipIdentityComponent& si,
             const PositionComponent& pos, const FacingComponent& facing,
-            const FactionComponent& /*fac*/)
+            const FactionComponent& fac, const HealthComponent& h)
         {
             const std::map<std::string, ShipVisuals>::const_iterator it =
                 m_visuals->ships.find(si.schematicId);
@@ -337,6 +337,18 @@ void ArenaView::drawShips(QPainter& painter)
             painter.setPen(QPen(it->second.outline, 1));
             painter.setBrush(it->second.fill);
             painter.drawPolygon(tri);
+
+            if (h.maxHp > 0.0f)
+            {
+                const float fraction = std::max(0.0f, h.hp / h.maxHp);
+                const qreal barW = static_cast<qreal>(fwd) * 2.0;
+                const qreal barH = static_cast<qreal>(tilePx()) * 0.12;
+                const qreal barX = center.x() - static_cast<qreal>(fwd);
+                const qreal barY = center.y() + static_cast<qreal>(fwd) + 1.0;
+                painter.fillRect(QRectF(barX, barY, barW, barH), QColor(60, 60, 60));
+                painter.fillRect(QRectF(barX, barY, barW * static_cast<qreal>(fraction), barH),
+                                 fac.isEnemy ? QColor(200, 60, 60) : QColor(60, 200, 60));
+            }
         });
 }
 

src/ui/GameWorldView.cpp

@@ -837,10 +837,10 @@ void GameWorldView::drawStations(QPainter& painter)
 void GameWorldView::drawShips(QPainter& painter)
 {
     m_sim->admin().forEach<ShipIdentityComponent, PositionComponent, FacingComponent,
-                           FactionComponent>(
+                           FactionComponent, HealthComponent>(
         [&](entt::entity /*e*/, const ShipIdentityComponent& si,
             const PositionComponent& pos, const FacingComponent& facing,
-            const FactionComponent& /*fac*/)
+            const FactionComponent& fac, const HealthComponent& h)
         {
             const std::map<std::string, ShipVisuals>::const_iterator it =
                 m_visuals->ships.find(si.schematicId);
@@ -864,6 +864,18 @@ void GameWorldView::drawShips(QPainter& painter)
             painter.setPen(QPen(it->second.outline, 1));
             painter.setBrush(it->second.fill);
             painter.drawPolygon(tri);
+
+            if (h.maxHp > 0.0f)
+            {
+                const float fraction = std::max(0.0f, h.hp / h.maxHp);
+                const qreal barW = static_cast<qreal>(fwd) * 2.0;
+                const qreal barH = static_cast<qreal>(tilePx()) * 0.12;
+                const qreal barX = center.x() - static_cast<qreal>(fwd);
+                const qreal barY = center.y() + static_cast<qreal>(fwd) + 1.0;
+                painter.fillRect(QRectF(barX, barY, barW, barH), QColor(60, 60, 60));
+                painter.fillRect(QRectF(barX, barY, barW * static_cast<qreal>(fraction), barH),
+                                 fac.isEnemy ? QColor(200, 60, 60) : QColor(60, 200, 60));
+            }
         });
 }