decouple main loop attempt

engine/gamemap/mapgens/default.go

@@ -87,7 +87,7 @@ func digHTunnel(l *gamemap.Level, x1,x2,y int, fillage types.RectFill) {
 		start = x2
 		finish = x1
 	}
-	for i := start; i <= finish; i++ {
+	for i := start; i <= finish - 1; i++ {
 		l.Tiles[i][y] = fillage.Body.(func() *gamemap.Tile)()
 	}
 }
@@ -101,7 +101,7 @@ func digVTunnel(l *gamemap.Level, y1,y2,x int, fillage types.RectFill) {
 		start = y2
 		finish = y1
 	}
-	for i := start; i <= finish; i++ {
+	for i := start; i <= finish - 1; i++ {
 		l.Tiles[x][i] = fillage.Body.(func() *gamemap.Tile)()
 	}
 }