Add demolish-mode vignette

src/ui/GameWorldView.cpp

@@ -433,6 +433,7 @@ void GameWorldView::paintGL()
     drawOverlays(painter);
     drawScreenSpace(painter);
     drawPauseBorder(painter);
+    drawDemolishBorder(painter);
     drawReplayOverlay(painter);
 }
 
@@ -1700,15 +1701,27 @@ void GameWorldView::drawScreenSpace(QPainter& /*painter*/)
 void GameWorldView::drawPauseBorder(QPainter& painter)
 {
     if (m_gameSpeedMultiplier > 0.0) { return; }
+    drawVignetteBorder(painter, QColor(0, 0, 0, 128));   // 50% black at the edge
+}
 
+void GameWorldView::drawDemolishBorder(QPainter& painter)
+{
+    if (!m_demolishMode) { return; }
+    // Reuse the demolish overlay color (with its configured alpha) as the edge color.
+    drawVignetteBorder(painter, m_visuals->overlays.demolishTint);
+}
+
+void GameWorldView::drawVignetteBorder(QPainter& painter, const QColor& edgeColor)
+{
     // Border thickness in pixels, capped so it never exceeds half the viewport on
-    // very small windows (which would leave no un-darkened center).
+    // very small windows (which would leave no un-tinted center).
     const qreal borderPx = std::min<qreal>(
         100.0, std::min(width(), height()) / 2.0);
     if (borderPx <= 0.0) { return; }
 
-    const QColor edge(0, 0, 0, 128);        // 50% black at the viewport edge
-    const QColor inner(0, 0, 0, 0);         // fully transparent toward the center
+    const QColor& edge = edgeColor;         // full color (and alpha) at the viewport edge
+    QColor inner = edgeColor;
+    inner.setAlpha(0);                      // same color, fully transparent toward the center
 
     const qreal w = width();
     const qreal h = height();