draw building icons in the game world

src/ui/GameWorldView.h

@@ -1,6 +1,7 @@
 #pragma once
 
 #include <map>
+#include <memory>
 #include <optional>
 #include <random>
 #include <set>
@@ -8,6 +9,7 @@
 #include <utility>
 #include <vector>
 
+#include <QColor>
 #include <QElapsedTimer>
 #include <QOpenGLWidget>
 #include <QPoint>
@@ -52,6 +54,7 @@ struct ParsedReplay;
 class ReplayPlayer;
 class Simulation;
 class QPainter;
+class QSvgRenderer;
 
 struct QPointCompare
 {
@@ -187,6 +190,19 @@ private:
                                QPoint anchorTile, Rotation rotation, bool valid,
                                bool showPortTargetGlyphs);
 
+    // Loads the per-building world icons (REQ-UI-WORLD-ICON) from
+    // <configDir>/../icons/buildings once at construction. Only the building
+    // types with a world icon are loaded (production buildings, HQ, stations);
+    // belts, splitters, and tunnels are deliberately excluded so their
+    // orientation stays readable. The SVG's chip background is stripped; the
+    // glyph is pre-rendered in both white and dark ink for auto-contrast.
+    void     loadBuildingIcons(const std::string& configDir);
+    // Draws a building's world icon glyph centered in box, choosing the white or
+    // dark pre-rendered variant by fill luminance so it stays legible. Returns
+    // false if the type has no world icon (caller falls back to the text glyph).
+    bool     drawBuildingIcon(QPainter& painter, BuildingType type,
+                              const QRectF& box, const QColor& fill) const;
+
     void     placeBlueprintAtTile(QPoint center);
 
     std::optional<QVector2D> entityPosition(entt::entity entity) const;
@@ -269,6 +285,17 @@ private:
     const GameConfig*    m_config;
     const VisualsConfig* m_visuals;
 
+    // World icon glyph renderers per building type (REQ-UI-WORLD-ICON), in a
+    // white and a dark variant so drawBuildingIcon can auto-contrast against the
+    // building's fill. Rendered as vector at the view scale each draw so they
+    // stay crisp. Populated once by loadBuildingIcons().
+    struct BuildingIconRenderers
+    {
+        std::unique_ptr<QSvgRenderer> white;
+        std::unique_ptr<QSvgRenderer> dark;
+    };
+    std::map<BuildingType, BuildingIconRenderers> m_buildingIcons;
+
     // Funnels all player input into the single Simulation::apply chokepoint.
     CommandManager m_commandManager;
     // A Reset command was enqueued; reset the view after the next drain applies it.