Mmark example

This commit ports the mmark example from the mmark branch, and also makes the complexity adjustable through up/down arrow keys.

examples/scenes/Cargo.toml

@@ -16,6 +16,7 @@ vello_svg = { path = "../../integrations/vello_svg" }
 anyhow = { workspace = true }
 clap = { workspace = true, features = ["derive"] }
 image = "0.24.5"
+rand = "0.8.5"
 instant = { workspace = true }
 
 # Used for the `download` command

examples/scenes/src/lib.rs

@@ -1,5 +1,6 @@
 pub mod download;
 mod images;
+mod mmark;
 mod simple_text;
 mod svg;
 mod test_scenes;
@@ -25,6 +26,7 @@ pub struct SceneParams<'a> {
     pub images: &'a mut ImageCache,
     pub resolution: Option<Vec2>,
     pub base_color: Option<vello::peniko::Color>,
+    pub complexity: usize,
 }
 
 pub struct SceneConfig {
@@ -34,10 +36,20 @@ pub struct SceneConfig {
 }
 
 pub struct ExampleScene {
-    pub function: Box<dyn FnMut(&mut SceneBuilder, &mut SceneParams)>,
+    pub function: Box<dyn TestScene>,
     pub config: SceneConfig,
 }
 
+pub trait TestScene {
+    fn render(&mut self, sb: &mut SceneBuilder, params: &mut SceneParams);
+}
+
+impl<F: FnMut(&mut SceneBuilder, &mut SceneParams)> TestScene for F {
+    fn render(&mut self, sb: &mut SceneBuilder, params: &mut SceneParams) {
+        self(sb, params);
+    }
+}
+
 pub struct SceneSet {
     pub scenes: Vec<ExampleScene>,
 }

examples/scenes/src/test_scenes.rs

@@ -31,8 +31,16 @@ pub fn test_scenes() -> SceneSet {
         },
         function: Box::new(splash_with_tiger()),
     };
+    let mmark_scene = ExampleScene {
+        config: SceneConfig {
+            animated: false,
+            name: "mmark".to_owned(),
+        },
+        function: Box::new(crate::mmark::MMark::new(80_000)),
+    };
     let scenes = vec![
         splash_scene,
+        mmark_scene,
         scene!(funky_paths),
         scene!(cardioid_and_friends),
         scene!(animated_text: animated),

examples/with_winit/src/lib.rs

@@ -113,6 +113,7 @@ fn run(
     let mut prior_position: Option<Vec2> = None;
     // We allow looping left and right through the scenes, so use a signed index
     let mut scene_ix: i32 = 0;
+    let mut complexity: usize = 0;
     if let Some(set_scene) = args.scene {
         scene_ix = set_scene;
     }
@@ -134,6 +135,8 @@ fn run(
                         match input.virtual_keycode {
                             Some(VirtualKeyCode::Left) => scene_ix = scene_ix.saturating_sub(1),
                             Some(VirtualKeyCode::Right) => scene_ix = scene_ix.saturating_add(1),
+                            Some(VirtualKeyCode::Up) => complexity += 1,
+                            Some(VirtualKeyCode::Down) => complexity = complexity.saturating_sub(1),
                             Some(key @ VirtualKeyCode::Q) | Some(key @ VirtualKeyCode::E) => {
                                 if let Some(prior_position) = prior_position {
                                     let is_clockwise = key == VirtualKeyCode::E;
@@ -295,8 +298,9 @@ fn run(
                 resolution: None,
                 base_color: None,
                 interactive: true,
+                complexity,
             };
-            (example_scene.function)(&mut builder, &mut scene_params);
+            example_scene.function.render(&mut builder, &mut scene_params);
 
             // If the user specifies a base color in the CLI we use that. Otherwise we use any
             // color specified by the scene. The default is black.