make math tiles read digits

README.md

@@ -10,7 +10,6 @@ copy/cut/paste selections
 timestamps in solutions and blueprints
 multiple input/output sets
 undo/redo
-make math tiles read digits
 tooltips
 lock tile types for early levels to make it less overwhelming
 display tool variant more clearly (it's not obvious there are more states)

src/marble_engine/tile.rs

@@ -150,10 +150,10 @@ impl Tile {
 	}
 
 	pub fn read_value(&self) -> MarbleValue {
-		if let Tile::Marble { value, dir: _ } = self {
-			*value
-		} else {
-			0
+		match self {
+			Tile::Marble { value, dir: _ } => *value,
+			Tile::Digit(d) => *d as MarbleValue,
+			_ => 0,
 		}
 	}