Add dashed_line benchmark

epaint/benches/benchmark.rs

@@ -0,0 +1,40 @@
+#![feature(test)]
+
+extern crate test;
+use epaint::{pos2, Color32, Shape, Stroke};
+use test::Bencher;
+
+#[bench]
+fn single_dashed_lines(b: &mut Bencher) {
+    b.iter(|| {
+        let mut v = Vec::new();
+
+        let line = [pos2(0.0, 0.0), pos2(50.0, 0.0), pos2(100.0, 1.0)];
+
+        for _ in 0..100 {
+            v.extend(Shape::dashed_line(
+                &line,
+                Stroke::new(1.5, Color32::RED),
+                10.0,
+                2.5,
+            ));
+        }
+
+        test::black_box(v);
+    });
+}
+
+#[bench]
+fn many_dashed_lines(b: &mut Bencher) {
+    b.iter(|| {
+        let mut v = Vec::new();
+
+        let line = [pos2(0.0, 0.0), pos2(50.0, 0.0), pos2(100.0, 1.0)];
+
+        for _ in 0..100 {
+            Shape::dashed_line_many(&line, Stroke::new(1.5, Color32::RED), 10.0, 2.5, &mut v);
+        }
+
+        test::black_box(v);
+    });
+}