1 files changed, 58 insertions, 0 deletions
diff --git a/examples/animation.rs b/examples/animation.rs
new file mode 100644
index 0000000..7f20bca
--- /dev/null
+++ b/examples/animation.rs
@@ -0,0 +1,58 @@
+use plotters::prelude::*;
+
+fn snowflake_iter(points: &[(f64, f64)]) -> Vec<(f64, f64)> {
+    let mut ret = vec![];
+    for i in 0..points.len() {
+        let (start, end) = (points[i], points[(i + 1) % points.len()]);
+        let t = ((end.0 - start.0) / 3.0, (end.1 - start.1) / 3.0);
+        let s = (
+            t.0 * 0.5 - t.1 * (0.75f64).sqrt(),
+            t.1 * 0.5 + (0.75f64).sqrt() * t.0,
+        );
+        ret.push(start);
+        ret.push((start.0 + t.0, start.1 + t.1));
+        ret.push((start.0 + t.0 + s.0, start.1 + t.1 + s.1));
+        ret.push((start.0 + t.0 * 2.0, start.1 + t.1 * 2.0));
+    }
+    ret
+}
+
+fn main() -> Result<(), Box<dyn std::error::Error>> {
+    let root = BitMapBackend::gif("plotters-doc-data/animation.gif", (800, 600), 1_000)?
+        .into_drawing_area();
+
+    for i in 0..8 {
+        root.fill(&WHITE)?;
+
+        let mut chart = ChartBuilder::on(&root)
+            .caption(
+                format!("Koch's Snowflake (n_iter = {})", i),
+                ("sans-serif", 50),
+            )
+            .build_ranged(-2.0..2.0, -1.5..1.5)?;
+
+        let mut snowflake_vertices = {
+            let mut current: Vec<(f64, f64)> = vec![
+                (0.0, 1.0),
+                ((3.0f64).sqrt() / 2.0, -0.5),
+                (-(3.0f64).sqrt() / 2.0, -0.5),
+            ];
+            for _ in 0..i {
+                current = snowflake_iter(&current[..]);
+            }
+            current
+        };
+
+        chart.draw_series(std::iter::once(Polygon::new(
+            snowflake_vertices.clone(),
+            &RED.mix(0.2),
+        )))?;
+
+        snowflake_vertices.push(snowflake_vertices[0]);
+        chart.draw_series(std::iter::once(PathElement::new(snowflake_vertices, &RED)))?;
+
+        root.present()?;
+    }
+
+    Ok(())
+}