From 5d27a8d3d1ac542b6a92857ee9e0395d80d4edee Mon Sep 17 00:00:00 2001
From: Duncan Fairbanks <duncanfairbanks6@gmail.com>
Date: Wed, 13 Dec 2023 16:12:51 -0800
Subject: [PATCH] use RayMap in the bevy_mod_raycast backend

---
 backends/bevy_picking_raycast/src/lib.rs | 116 +++++++++--------------
 1 file changed, 47 insertions(+), 69 deletions(-)

diff --git a/backends/bevy_picking_raycast/src/lib.rs b/backends/bevy_picking_raycast/src/lib.rs
index 401f7aa4..60923626 100644
--- a/backends/bevy_picking_raycast/src/lib.rs
+++ b/backends/bevy_picking_raycast/src/lib.rs
@@ -18,11 +18,9 @@ use bevy_app::prelude::*;
 use bevy_ecs::prelude::*;
 use bevy_reflect::prelude::*;
 use bevy_render::{prelude::*, view::RenderLayers};
-use bevy_transform::prelude::*;
-use bevy_window::{PrimaryWindow, Window};
 
 use bevy_mod_raycast::prelude::*;
-use bevy_picking_core::backend::prelude::*;
+use bevy_picking_core::{backend::prelude::*, ray::RayMap};
 
 // Re-export for uses who want this
 pub use bevy_mod_raycast;
@@ -63,81 +61,61 @@ impl Plugin for RaycastBackend {
 /// Raycasts into the scene using [`RaycastBackendSettings`] and [`PointerLocation`]s, then outputs
 /// [`PointerHits`].
 pub fn update_hits(
-    pointers: Query<(&PointerId, &PointerLocation)>,
-    primary_window_entity: Query<Entity, With<PrimaryWindow>>,
-    primary_window: Query<&Window, With<PrimaryWindow>>,
-    picking_cameras: Query<(
-        Entity,
-        &Camera,
-        &GlobalTransform,
-        Option<&RaycastPickable>,
-        Option<&RenderLayers>,
-    )>,
+    backend_settings: Res<RaycastBackendSettings>,
+    ray_map: Res<RayMap>,
+    picking_cameras: Query<(&Camera, Option<&RaycastPickable>, Option<&RenderLayers>)>,
     pickables: Query<&Pickable>,
     marked_targets: Query<&RaycastPickable>,
     layers: Query<&RenderLayers>,
-    backend_settings: Res<RaycastBackendSettings>,
     mut raycast: Raycast,
     mut output_events: EventWriter<PointerHits>,
 ) {
-    for (pointer_id, pointer_location) in &pointers {
-        let pointer_location = match pointer_location.location() {
-            Some(l) => l,
-            None => continue,
+    for (&ray_id, &ray) in ray_map.map().iter() {
+        let Ok((camera, cam_pickable, cam_layers)) = picking_cameras.get(ray_id.camera) else {
+            continue;
         };
-        for (cam_entity, camera, ray, cam_layers) in picking_cameras
-            .iter()
-            .filter(|(_, camera, ..)| {
-                camera.is_active && pointer_location.is_in_viewport(camera, &primary_window_entity)
-            })
-            .filter(|(.., marker, _)| marker.is_some() || !backend_settings.require_markers)
-            .filter_map(|(entity, camera, transform, _, layers)| {
-                Ray3d::from_screenspace(
-                    pointer_location.position,
-                    camera,
-                    transform,
-                    primary_window.single(),
-                )
-                .map(|ray| (entity, camera, ray, layers))
-            })
-        {
-            let settings = RaycastSettings {
-                visibility: RaycastVisibility::MustBeVisibleAndInView,
-                filter: &|entity| {
-                    let marker_requirement =
-                        !backend_settings.require_markers || marked_targets.get(entity).is_ok();
+        if backend_settings.require_markers && cam_pickable.is_none() {
+            continue;
+        }
 
-                    // Cameras missing render layers intersect all layers
-                    let cam_layers = cam_layers.copied().unwrap_or(RenderLayers::all());
-                    // Other entities missing render layers are on the default layer 0
-                    let entity_layers = layers.get(entity).copied().unwrap_or_default();
-                    let render_layers_match = cam_layers.intersects(&entity_layers);
+        // Cameras missing render layers intersect all layers
+        let cam_layers = cam_layers.copied().unwrap_or_else(RenderLayers::all);
 
-                    marker_requirement && render_layers_match
-                },
-                early_exit_test: &|entity_hit| {
-                    pickables
-                        .get(entity_hit)
-                        .is_ok_and(|pickable| pickable.should_block_lower)
-                },
-            };
-            let picks = raycast
-                .cast_ray(ray, &settings)
-                .iter()
-                .map(|(entity, hit)| {
-                    let hit_data = HitData::new(
-                        cam_entity,
-                        hit.distance(),
-                        Some(hit.position()),
-                        Some(hit.normal()),
-                    );
-                    (*entity, hit_data)
-                })
-                .collect::<Vec<_>>();
-            let order = camera.order as f32;
-            if !picks.is_empty() {
-                output_events.send(PointerHits::new(*pointer_id, picks, order));
-            }
+        let ray = Ray3d::from(ray);
+        let settings = RaycastSettings {
+            visibility: RaycastVisibility::MustBeVisibleAndInView,
+            filter: &|entity| {
+                let marker_requirement =
+                    !backend_settings.require_markers || marked_targets.get(entity).is_ok();
+
+                // Other entities missing render layers are on the default layer 0
+                let entity_layers = layers.get(entity).copied().unwrap_or_default();
+                let render_layers_match = cam_layers.intersects(&entity_layers);
+
+                marker_requirement && render_layers_match
+            },
+            early_exit_test: &|entity_hit| {
+                pickables
+                    .get(entity_hit)
+                    .is_ok_and(|pickable| pickable.should_block_lower)
+            },
+        };
+        let picks = raycast
+            .cast_ray(ray, &settings)
+            .iter()
+            .map(|(entity, hit)| {
+                let hit_data = HitData::new(
+                    ray_id.camera,
+                    hit.distance(),
+                    Some(hit.position()),
+                    Some(hit.normal()),
+                );
+                (*entity, hit_data)
+            })
+            .collect::<Vec<_>>();
+        let order = camera.order as f32;
+        if !picks.is_empty() {
+            output_events.send(PointerHits::new(ray_id.pointer, picks, order));
         }
     }
 }