simple legacy comparison example

examples/simple_legacy_comparison.rs

@@ -0,0 +1,116 @@
+use bevy::prelude::*;
+use std::collections::VecDeque;
+use rand::{rngs::StdRng, Rng, SeedableRng};
+fn main() {
+    AppBuilder::new().add_defaults_legacy().add_system(build_move_system()).add_system(build_print_status_system()).setup_world(setup).run();
+}
+
+fn build_move_system() -> Box<dyn Schedulable> {
+    SystemBuilder::new("Move")
+        .read_resource::<Time>()
+        .with_query(<(Write<Translation>, Write<Material>)>::query())
+        .build(move |_, world, time, person_query| {
+            for (mut translation, mut material) in person_query.iter_mut(world) {
+                translation.0 += math::vec3(1.0, 0.0, 0.0) * time.delta_seconds;
+            }
+        })
+}
+
+fn build_print_status_system() -> Box<dyn Schedulable> {
+    let mut elapsed = 0.0;
+    let mut frame_time_total = 0.0;
+    let mut frame_time_count = 0;
+    let frame_time_max = 10;
+    let mut frame_time_values = VecDeque::new();
+    SystemBuilder::new("PrintStatus")
+        .read_resource::<Time>()
+        .build(move |_, _world, time, _queries| {
+            elapsed += time.delta_seconds;
+            frame_time_values.push_front(time.delta_seconds);
+            frame_time_total += time.delta_seconds;
+            frame_time_count += 1;
+            if frame_time_count > frame_time_max {
+                frame_time_count = frame_time_max;
+                frame_time_total -= frame_time_values.pop_back().unwrap();
+            }
+            if elapsed > 1.0 {
+                if frame_time_count > 0 && frame_time_total > 0.0 {
+                    println!(
+                        "fps: {}",
+                        1.0 / (frame_time_total / frame_time_count as f32)
+                    )
+                }
+                elapsed = 0.0;
+            }
+        })
+}
+
+fn setup(world: &mut World) {
+    let cube = Mesh::load(MeshType::Cube);
+    let plane = Mesh::load(MeshType::Plane { size: 10.0 });
+
+    let (cube_handle, plane_handle) = {
+        let mut mesh_storage = world.resources.get_mut::<AssetStorage<Mesh>>().unwrap();
+        (mesh_storage.add(cube), mesh_storage.add(plane))
+    };
+    
+    let mut builder = world.build()
+        // plane
+        .add_archetype(MeshEntity {
+            mesh: plane_handle.clone(),
+            material: Material::new(Albedo::Color(math::vec4(0.1, 0.2, 0.1, 1.0))),
+            local_to_world: LocalToWorld::identity(),
+            translation: Translation::new(0.0, 0.0, 0.0),
+        })
+        // cube
+        .add_archetype(MeshEntity {
+            mesh: cube_handle.clone(),
+            material: Material::new(Albedo::Color(math::vec4(0.5, 0.3, 0.3, 1.0))),
+            local_to_world: LocalToWorld::identity(),
+            translation: Translation::new(0.0, 0.0, 1.0),
+        })
+        // light
+        .add_archetype(LightEntity {
+            light: Light {
+                color: wgpu::Color {
+                    r: 0.8,
+                    g: 0.8,
+                    b: 0.5,
+                    a: 1.0,
+                },
+                fov: f32::to_radians(60.0),
+                depth: 0.1..50.0,
+                target_view: None,
+            },
+            local_to_world: LocalToWorld::identity(),
+            translation: Translation::new(4.0, -4.0, 5.0),
+            rotation: Rotation::from_euler_angles(0.0, 0.0, 0.0),
+        })
+        // camera
+        .add_archetype(CameraEntity {
+            camera: Camera::new(CameraType::Projection {
+                fov: std::f32::consts::PI / 4.0,
+                near: 1.0,
+                far: 1000.0,
+                aspect_ratio: 1.0,
+            }),
+            active_camera: ActiveCamera,
+            local_to_world: LocalToWorld(Mat4::look_at_rh(
+                Vec3::new(3.0, 8.0, 5.0),
+                Vec3::new(0.0, 0.0, 0.0),
+                Vec3::new(0.0, 0.0, 1.0),
+            )),
+        });
+
+        let mut rng = StdRng::from_entropy();
+        for _ in 0..10000 {
+            builder = builder.add_archetype(MeshEntity {
+            mesh: cube_handle.clone(),
+            material: Material::new(Albedo::Color(math::vec4(0.5, 0.3, 0.3, 1.0))),
+            local_to_world: LocalToWorld::identity(),
+            translation: Translation::new(rng.gen_range(-50.0, 50.0), rng.gen_range(-50.0, 50.0), 0.0),
+            });
+        }
+    
+        builder.build()    
+}