Add coin animation

mario/main.cpp

@@ -142,6 +142,11 @@ void doInput( std::shared_ptr< SDLPP::Scene > scene ) {
             coin_count++;
             coins->changeText(std::to_string(coin_count) + " COINS");
         }
+        if ( mv.hasCoinBlock() ) {
+            auto coin = mv.getCoinBlock();
+            scene->addObject(coin);
+            scene->setZIndex(coin, 1);
+        }
 
         // if player is > 0.7 of playground, move everything left
         auto playerX = mario->getRect().x;