diff --git a/examples/advanced/cloth.py b/examples/advanced/cloth.py
new file mode 100644
index 00000000..ca759ab7
--- /dev/null
+++ b/examples/advanced/cloth.py
@@ -0,0 +1,153 @@
+import asyncio
+from dataclasses import dataclass
+
+import cv2
+import numpy as np
+from batgrl.app import App
+from batgrl.colors import AWHITE, AColor
+from batgrl.gadgets.graphics import Graphics, Size
+from batgrl.gadgets.slider import Slider
+from batgrl.gadgets.text import Text
+from batgrl.io import MouseButton
+from numpy.typing import NDArray
+
+MESH_SIZE = 11, 21
+DAMPING = 0.97
+GRAVITY = np.array([0.015, 0])
+
+
+@dataclass
+class Node:
+    position: NDArray[np.float64]
+
+    def __post_init__(self):
+        self.velocity = np.zeros(2)
+        self.acceleration = np.zeros(2)
+        self.is_anchored = False
+
+    def step(self):
+        if not self.is_anchored:
+            self.velocity += self.acceleration
+            self.position += self.velocity
+            self.velocity *= DAMPING
+        self.acceleration[:] = GRAVITY
+
+
+@dataclass
+class Link:
+    a: Node
+    b: Node
+
+    def __post_init__(self):
+        self.rest_length = np.linalg.norm(self.a.position - self.b.position)
+
+    def step(self):
+        direction = self.b.position - self.a.position
+        length = np.linalg.norm(direction)
+        stretch = (length - self.rest_length) / length
+        if stretch > 0:
+            momentum = direction * stretch * 0.5
+            self.a.acceleration += momentum
+            self.b.acceleration -= momentum
+
+
+def make_mesh(size: Size, nanchors: int) -> tuple[list[Node], list[Link]]:
+    height, width = size
+
+    nodes = [
+        Node(position=np.array([y, x], dtype=float))
+        for y in range(height)
+        for x in range(width)
+    ]
+
+    links = []
+    for y in range(height):
+        for x in range(width):
+            a = nodes[y * width + x]
+
+            if y != height - 1:  # attach down
+                b = nodes[(y + 1) * width + x]
+                links.append(Link(a, b))
+
+            if x != width - 1:  # attach right
+                b = nodes[y * width + x + 1]
+                links.append(Link(a, b))
+
+    return nodes, links
+
+
+class Cloth(Graphics):
+    def __init__(self, mesh_size: Size, scale=5, mesh_color: AColor = AWHITE, **kwargs):
+        super().__init__(**kwargs)
+        self.nodes, self.links = make_mesh(mesh_size, nanchors=21)
+        self.scale = scale
+        self.mesh_color = mesh_color
+        self.on_size()
+
+    def on_size(self):
+        super().on_size()
+        self.h_offset = (self.width - self.nodes[-1].position[1] * self.scale) / 2
+
+    def scale_pos(self, pos: NDArray[np.float64]) -> NDArray[np.float64]:
+        scaled = self.scale * pos
+        scaled[1] += self.h_offset
+        return scaled
+
+    def step(self):
+        self.clear()
+        for link in self.links:
+            link.step()
+        for node in self.nodes:
+            node.step()
+        for link in self.links:
+            cv2.line(
+                self.texture,
+                self.scale_pos(link.a.position).astype(int)[::-1],
+                self.scale_pos(link.b.position).astype(int)[::-1],
+                self.mesh_color,
+            )
+
+    def on_mouse(self, mouse_event):
+        if mouse_event.button != MouseButton.LEFT:
+            return False
+        mouse_pos = np.array(self.to_local(mouse_event.position))
+        for node in self.nodes:
+            force_direction = self.scale_pos(node.position) - mouse_pos
+            magnitude = np.linalg.norm(force_direction)
+            if magnitude != 0:
+                force_normal = force_direction / magnitude
+                node.acceleration -= 0.01 * force_normal
+        return True
+
+
+class ClothApp(App):
+    async def on_start(self):
+        cloth = Cloth(
+            mesh_size=MESH_SIZE, size_hint={"height_hint": 1.0, "width_hint": 1.0}
+        )
+        slider_label = Text(size=(1, 11))
+
+        def update_anchors(nanchors):
+            nanchors = round(nanchors)
+            slider_label.add_str(f"Anchors: {nanchors:02d}")
+            height, width = MESH_SIZE
+            for y in range(height):
+                for x in range(width):
+                    node = cloth.nodes[y * width + x]
+                    node.position[:] = y, x
+                    node.is_anchored = False
+            for i in np.linspace(0, width - 1, nanchors).astype(int):
+                cloth.nodes[i].is_anchored = True
+
+        slider = Slider(
+            size=(1, 11), min=2, max=13, start_value=5, callback=update_anchors
+        )
+        slider.top = slider_label.bottom
+        self.add_gadgets(cloth, slider_label, slider)
+        while True:
+            cloth.step()
+            await asyncio.sleep(0)
+
+
+if __name__ == "__main__":
+    ClothApp(title="Cloth Simulation").run()
diff --git a/examples/advanced/cloth/README.md b/examples/advanced/cloth/README.md
deleted file mode 100644
index a8706e4d..00000000
--- a/examples/advanced/cloth/README.md
+++ /dev/null
@@ -1,3 +0,0 @@
-# Cloth Simulation
-
-A cloth simulation with batgrl. `python -m cloth` to run.
diff --git a/examples/advanced/cloth/cloth/__init__.py b/examples/advanced/cloth/cloth/__init__.py
deleted file mode 100644
index e69de29b..00000000
diff --git a/examples/advanced/cloth/cloth/__main__.py b/examples/advanced/cloth/cloth/__main__.py
deleted file mode 100644
index 1732df3e..00000000
--- a/examples/advanced/cloth/cloth/__main__.py
+++ /dev/null
@@ -1,20 +0,0 @@
-from batgrl.app import App
-
-from .cloth import Cloth
-
-MESH_SIZE = 11, 21
-
-
-class ClothApp(App):
-    async def on_start(self):
-        cloth = Cloth(
-            mesh_size=MESH_SIZE, size_hint={"height_hint": 1.0, "width_hint": 1.0}
-        )
-
-        self.add_gadget(cloth)
-
-        await cloth.step_forever()
-
-
-if __name__ == "__main__":
-    ClothApp(title="Cloth Simulation").run()
diff --git a/examples/advanced/cloth/cloth/cloth.py b/examples/advanced/cloth/cloth/cloth.py
deleted file mode 100644
index 71171c02..00000000
--- a/examples/advanced/cloth/cloth/cloth.py
+++ /dev/null
@@ -1,73 +0,0 @@
-import asyncio
-
-import cv2
-import numpy as np
-from batgrl.colors import AWHITE, AColor
-from batgrl.gadgets.graphics import Graphics, Size
-from batgrl.io import MouseButton
-
-from .mesh import Mesh
-
-
-class Cloth(Graphics):
-    def __init__(self, mesh_size: Size, scale=5, mesh_color: AColor = AWHITE, **kwargs):
-        super().__init__(**kwargs)
-
-        self.mesh = Mesh(mesh_size, nanchors=5)
-        self.scale = scale
-        self.mesh_color = mesh_color
-
-        self.on_size()
-
-    def on_size(self):
-        h, w = self._size
-
-        self.texture = np.full((h * 2, w, 4), self.default_color, dtype=np.uint8)
-
-        # Center the nodes horizontally in the gadget with following offset:
-        self.h_offset = (
-            (self.width - self.mesh.nodes[-1].position.imag * self.scale) / 2 * 1j
-        )
-
-    def step(self):
-        """Step the mesh and draw a line for each link."""
-        texture = self.texture
-        texture[:] = self.default_color
-
-        color = self.mesh_color
-        mesh = self.mesh
-        scale = self.scale
-        h_offset = self.h_offset
-
-        mesh.step()
-
-        for link in mesh.links:
-            a_pos = scale * link.a.position + h_offset
-            ay, ax = int(a_pos.real), int(a_pos.imag)
-
-            b_pos = scale * link.b.position + h_offset
-            by, bx = int(b_pos.real), int(b_pos.imag)
-
-            cv2.line(texture, (ax, ay), (bx, by), color)
-
-    async def step_forever(self):
-        while True:
-            self.step()
-            await asyncio.sleep(0)
-
-    def on_mouse(self, mouse_event):
-        if mouse_event.button != MouseButton.LEFT:
-            return False
-
-        mouse_pos = complex(*self.to_local(mouse_event.position))
-        scale = self.scale
-        h_offset = self.h_offset
-
-        for node in self.mesh.nodes:
-            force_direction = scale * node.position + h_offset - mouse_pos
-            magnitude = abs(force_direction)
-            if magnitude != 0:
-                force_normal = force_direction / magnitude
-                node.acceleration -= 0.01 * force_normal
-
-        return True
diff --git a/examples/advanced/cloth/cloth/link.py b/examples/advanced/cloth/cloth/link.py
deleted file mode 100644
index 83c1f8ad..00000000
--- a/examples/advanced/cloth/cloth/link.py
+++ /dev/null
@@ -1,25 +0,0 @@
-from .node import Node
-
-
-class Link:
-    def __init__(self, a: Node, b: Node):
-        self.a = a
-        self.b = b
-
-        self.rest_length = abs(a.position - b.position)
-
-    def step(self):
-        a = self.a
-        b = self.b
-
-        direction = b.position - a.position
-        length = abs(direction)
-        stretch = (length - self.rest_length) / length
-
-        if stretch > 0:
-            # Typical calculation is `direction * stretch / (a.mass + b.mass)`,
-            # but nodes have implicit mass of 1.
-            momentum = direction * stretch * 0.5
-
-            a.acceleration += momentum
-            b.acceleration -= momentum
diff --git a/examples/advanced/cloth/cloth/mesh.py b/examples/advanced/cloth/cloth/mesh.py
deleted file mode 100644
index 78728bed..00000000
--- a/examples/advanced/cloth/cloth/mesh.py
+++ /dev/null
@@ -1,47 +0,0 @@
-import numpy as np
-
-from .link import Link
-from .node import Node
-
-
-class Mesh:
-    def __init__(self, size, *, nanchors=None):
-        height, width = size
-
-        # Create a grid of nodes.
-        nodes = [
-            [Node(position=complex(y, x)) for x in range(width)] for y in range(height)
-        ]
-
-        # Link adjacent nodes.
-        links = []
-        for y in range(height):
-            for x in range(width):
-                a = nodes[y][x]
-
-                if y != height - 1:  # attach down
-                    b = nodes[y + 1][x]
-                    links.append(Link(a, b))
-
-                if x != width - 1:  # attach right
-                    b = nodes[y][x + 1]
-                    links.append(Link(a, b))
-
-        if nanchors is None:  # Anchor entire top row.
-            for node in nodes[0]:
-                node.is_anchored = True
-        elif nanchors == 1:  # Anchor midpoint of top row.
-            nodes[0][width // 2].is_anchored = True
-        else:  # Evenly spaced nanchors anchors on top row.
-            for i in np.linspace(0, width - 1, nanchors).astype(int):
-                nodes[0][i].is_anchored = True
-
-        self.nodes = [node for row in nodes for node in row]  # flatten
-        self.links = links
-
-    def step(self):
-        for link in self.links:
-            link.step()
-
-        for node in self.nodes:
-            node.step()
diff --git a/examples/advanced/cloth/cloth/node.py b/examples/advanced/cloth/cloth/node.py
deleted file mode 100644
index b44dcb57..00000000
--- a/examples/advanced/cloth/cloth/node.py
+++ /dev/null
@@ -1,18 +0,0 @@
-FRICTION = 0.97  # Decrease this value for *more* friction.
-GRAVITY = 0.015 + 0j
-
-
-class Node:
-    def __init__(self, position: complex, *, is_anchored=False):
-        self.position = position
-        self.velocity = self.acceleration = 0j
-        self.is_anchored = is_anchored
-
-    def step(self):
-        if not self.is_anchored:
-            self.velocity += self.acceleration
-            self.position += self.velocity
-
-            self.velocity *= FRICTION
-
-        self.acceleration = GRAVITY