diff --git a/assets/step.png b/assets/step.png
index ddb7dc9..519d351 100644
Binary files a/assets/step.png and b/assets/step.png differ
diff --git a/src/editor.rs b/src/editor.rs
index dee5324..1168b52 100644
--- a/src/editor.rs
+++ b/src/editor.rs
@@ -54,6 +54,7 @@ enum Popup {
 #[derive(Debug, Clone)]
 enum Tool {
 	None,
+	Erase,
 	SetTile(Tile),
 	Digits(Option<Pos>),
 	Math,
@@ -200,7 +201,11 @@ impl Editor {
 					WireType::Cross => WireType::Vertical,
 				}
 			}
-			Tool::None | Tool::SetTile(_) | Tool::Digits(_) | Tool::SelectArea(_, _) => (),
+			Tool::None
+			| Tool::Erase
+			| Tool::SetTile(_)
+			| Tool::Digits(_)
+			| Tool::SelectArea(_, _) => (),
 		}
 	}
 
@@ -470,7 +475,7 @@ impl Editor {
 				border,
 			);
 		};
-		tool_button((0, -2), "eraser", Tool::SetTile(Tile::from_char(' ')));
+		tool_button((0, -2), "eraser", Tool::Erase);
 		tool_button((1, -2), "selection", Tool::SelectArea(None, false));
 		tool_button((0, -1), "digit_tool", Tool::Digits(None));
 		tool_button((1, -1), "transparent", Tool::None);
@@ -612,13 +617,8 @@ impl Editor {
 				if self.active_tool != Tool::None {
 					let tex = match self.active_tool {
 						Tool::None => unreachable!(),
-						Tool::SetTile(t) => {
-							if t == Tile::Blank {
-								"selection".into()
-							} else {
-								t.texture()
-							}
-						}
+						Tool::Erase => "selection".into(),
+						Tool::SetTile(t) => t.texture(),
 						Tool::Math => format!("{}_off", self.tool_menu_math.texture_name()),
 						Tool::Gate => format!("{}_off", self.tool_menu_gate.texture_name()),
 						Tool::Wire => format!("{}_off", self.tool_menu_wire.texture_name()),
@@ -639,6 +639,7 @@ impl Editor {
 				if d.is_mouse_button_pressed(MouseButton::MOUSE_BUTTON_LEFT) {
 					match self.active_tool {
 						Tool::None => (),
+						Tool::Erase => (),
 						Tool::SetTile(tile) => self.set_tile(tile_pos.into(), tile),
 						Tool::Math => self.set_tile(
 							tile_pos.into(),
@@ -670,6 +671,11 @@ impl Editor {
 						Tool::SelectArea(_, _) => (),
 					}
 				}
+				if d.is_mouse_button_down(MouseButton::MOUSE_BUTTON_LEFT) {
+					if self.active_tool == Tool::Erase {
+						self.set_tile(tile_pos.into(), Tile::Blank)
+					}
+				}
 				if let Tool::SelectArea(selection, is_selecting) = &mut self.active_tool {
 					if d.is_mouse_button_down(MouseButton::MOUSE_BUTTON_LEFT) {
 						if *is_selecting {
diff --git a/src/marble_engine/board.rs b/src/marble_engine/board.rs
index ea4249f..d86786e 100644
--- a/src/marble_engine/board.rs
+++ b/src/marble_engine/board.rs
@@ -219,41 +219,38 @@ impl Board {
 	}
 
 	pub fn trim_size(&mut self) {
+		// top
 		{
-			let mut top_blanks = 0;
-			while top_blanks < self.height && self.rows[top_blanks].iter().all(Tile::is_blank) {
-				top_blanks += 1;
+			let mut n = 0;
+			while n < self.height && self.rows[n].iter().all(Tile::is_blank) {
+				n += 1;
 			}
-			let trim_top = top_blanks.saturating_sub(2);
+			let trim_top = n.saturating_sub(2);
 			for _ in 0..trim_top {
 				self.rows.remove(0);
 			}
 			self.offset_y -= trim_top as isize;
 			self.height -= trim_top;
 		}
+		// bottom
 		{
-			let mut bottom_blanks = 0;
-			while bottom_blanks < self.height
-				&& self.rows[self.height - bottom_blanks - 1]
-					.iter()
-					.all(Tile::is_blank)
-			{
-				bottom_blanks += 1;
+			let mut n = 0;
+			while n < self.height && self.rows[self.height - n - 1].iter().all(Tile::is_blank) {
+				n += 1;
 			}
-			let trim_bottom = bottom_blanks.saturating_sub(2);
+			let trim_bottom = n.saturating_sub(2);
 			for _ in 0..trim_bottom {
 				self.rows.pop();
 			}
 			self.height -= trim_bottom;
 		}
+		// left
 		{
-			let mut left_blanks = 0;
-			while left_blanks < self.width
-				&& self.rows.iter().all(|row| row[left_blanks].is_blank())
-			{
-				left_blanks += 1;
+			let mut n = 0;
+			while n < self.width && self.rows.iter().all(|row| row[n].is_blank()) {
+				n += 1;
 			}
-			let trim_left = left_blanks.saturating_sub(2);
+			let trim_left = n.saturating_sub(2);
 			for row in &mut self.rows {
 				for _ in 0..trim_left {
 					row.remove(0);
@@ -262,17 +259,13 @@ impl Board {
 			self.offset_x -= trim_left as isize;
 			self.width -= trim_left;
 		}
+		// right
 		{
-			let mut right_blanks = 0;
-			while right_blanks < self.height
-				&& self
-					.rows
-					.iter()
-					.all(|row| row[self.width - right_blanks - 1].is_blank())
-			{
-				right_blanks += 1;
+			let mut n = 0;
+			while n < self.width && self.rows.iter().all(|r| r[self.width - n - 1].is_blank()) {
+				n += 1;
 			}
-			let trim_right = right_blanks.saturating_sub(2);
+			let trim_right = n.saturating_sub(2);
 			for row in &mut self.rows {
 				for _ in 0..trim_right {
 					row.pop();