diff --git a/Aquaria/WorldMapRender.cpp b/Aquaria/WorldMapRender.cpp
index 6b2d13b..d282c3b 100644
--- a/Aquaria/WorldMapRender.cpp
+++ b/Aquaria/WorldMapRender.cpp
@@ -468,7 +468,8 @@ static void tileDataToVis(WorldMapTile *tile, Array2d<Vector>& vis)
 	{
 		const float a = tile->prerevealed ? 0.4f :  baseMapSegAlpha;
 		Vector *gp = vis.data();
-		for(size_t i = 0; i < vis.linearsize(); ++i)
+		const size_t n = vis.linearsize();
+		for(size_t i = 0; i < n; ++i)
 			gp[i].z = a;
 	}
 }
@@ -565,6 +566,7 @@ void WorldMapRender::setVis(WorldMapTile *tile)
 		RenderGrid *g = tile->q->setSegs(MAPVIS_SUBDIV, MAPVIS_SUBDIV, 0, 0, 0, 0, 2.0, 1);
 		if(g)
 		{
+			g->gridType = GRID_UNDEFINED;
 			g->drawOrder = GRID_DRAW_WORLDMAP;
 			tileDataToVis(tile, g->array2d());
 		}
diff --git a/BBGE/RenderGrid.h b/BBGE/RenderGrid.h
index c8a4169..1c0b8fb 100644
--- a/BBGE/RenderGrid.h
+++ b/BBGE/RenderGrid.h
@@ -8,19 +8,19 @@ struct RenderState;
 
 enum GridDrawOrder
 {
-	GRID_DRAW_WORLDMAP = -1, // LRTB order, uses grid.z as alpha
 	GRID_DRAW_LRTB = 0, // the default. ignores grid.z
 	GRID_DRAW_LRBT = 1, // Y axis inverted
+	GRID_DRAW_WORLDMAP = 2, // LRTB order, uses grid.z as alpha
 
 	GRID_DRAW_DEFAULT = GRID_DRAW_LRTB
 };
 
 enum GridType
 {
-	GRID_UNDEFINED = -1,
-	GRID_WAVY	= 0,
-	GRID_STRIP	= 1, // quad is in strip mode
-	GRID_INTERP = 2, // quad is in grid mode
+	GRID_UNDEFINED = 0,
+	GRID_WAVY	= 1,
+	GRID_STRIP	= 2, // quad is in strip mode
+	GRID_INTERP = 3, // quad is in grid mode
 };
 
 class RenderGrid