implement display construction percentage

src/ui/GameWorldView.cpp

@@ -617,6 +617,36 @@ void GameWorldView::drawBuildings(QPainter& painter)
         const BuildingDef* siteDef = findBuildingDef(s.type);
         if (siteDef)
         {
+            // Glyph + progress percentage
+            const Tick durationTicks = secondsToTicks(siteDef->constructionTimeSeconds);
+            int pct = 0;
+            if (s.completesAt > 0 && durationTicks > 0)
+            {
+                const Tick elapsed = m_sim->currentTick()
+                    - (s.completesAt - durationTicks);
+                pct = static_cast<int>(
+                    std::max(Tick(0), std::min(durationTicks, elapsed))
+                    * 100 / durationTicks);
+            }
+            const QString pctText = QString::number(pct) + "%";
+
+            painter.setPen(bv.outline);
+            if (!bv.glyph.isEmpty())
+            {
+                const QRectF topHalf(bboxRect.x(), bboxRect.y(),
+                                     bboxRect.width(), bboxRect.height() * 0.5);
+                const QRectF botHalf(bboxRect.x(),
+                                     bboxRect.y() + bboxRect.height() * 0.5,
+                                     bboxRect.width(), bboxRect.height() * 0.5);
+                painter.drawText(topHalf, Qt::AlignCenter, bv.glyph);
+                painter.drawText(botHalf, Qt::AlignCenter, pctText);
+            }
+            else
+            {
+                painter.drawText(bboxRect, Qt::AlignCenter, pctText);
+            }
+
+            // Port glyphs
             const ParsedSurfaceMask siteMask =
                 parseSurfaceMask(siteDef->surfaceMask, s.rotation);
             for (const Port& port : siteMask.outputPorts)