Don't render HUD map if invisible

Very nice on debug builds since you can avoid huge FPS drops by hiding the map now.

src/d/d_meter_map.cpp

@@ -593,6 +593,14 @@ void dMeterMap_c::_draw() {
         dComIfGd_set2DOpa(this);
     }
     #else
+#if TARGET_PC
+    // Optimization: don't draw map if it's off-screen/invisible.
+    // Especially useful in debug builds on Hyrule field etc., it's slow!
+    if ((!mMapIsInside && mSlidePositionOffset == getDispPosOutSide_OffsetX()) || mMapAlpha == 0) {
+        return;
+    }
+#endif
+
     mMap->_draw();
     dComIfGd_set2DOpa(this);
     #endif