From 24db52abd9aa5564248444060728aba8a4c2554a Mon Sep 17 00:00:00 2001
From: Nolan Darilek <nolan@thewordnerd.info>
Date: Wed, 9 Jun 2021 17:42:04 -0500
Subject: [PATCH] Refine visibility algorithm.

---
 src/visibility.rs | 24 +++++++++++++++++++++---
 1 file changed, 21 insertions(+), 3 deletions(-)

diff --git a/src/visibility.rs b/src/visibility.rs
index 508d888..3bb81ae 100644
--- a/src/visibility.rs
+++ b/src/visibility.rs
@@ -49,6 +49,16 @@ impl Viewshed {
 #[reflect(Component)]
 pub struct VisibleTiles(pub Vec<bool>);
 
+impl PointLike for Coord {
+    fn x(&self) -> f32 {
+        self.x as f32
+    }
+
+    fn y(&self) -> f32 {
+        self.y as f32
+    }
+}
+
 fn add_visibility_indices(
     mut commands: Commands,
     query: Query<(Entity, &Map), (Added<Map>, Without<VisibleTiles>, Without<RevealedTiles>)>,
@@ -85,13 +95,13 @@ where
 }
 
 fn update_viewshed<'a>(
-    mut viewers: Query<(&mut Viewshed, &Coordinates), Changed<Coordinates>>,
+    mut viewers: Query<(Entity, &mut Viewshed, &Coordinates), Changed<Coordinates>>,
     map: Query<&Map>,
     query_pipeline: Res<QueryPipeline>,
     collider_query: QueryPipelineColliderComponentsQuery,
     blocks_visibility: Query<&BlocksVisibility>,
 ) {
-    for (mut viewshed, start) in viewers.iter_mut() {
+    for (viewer_entity, mut viewshed, start) in viewers.iter_mut() {
         for map in map.iter() {
             let mut context: Context<u8> = Context::default();
             let vision_distance = vision_distance::Circle::new(viewshed.range);
@@ -99,7 +109,13 @@ fn update_viewshed<'a>(
             viewshed.visible.clear();
             let collider_set = QueryPipelineColliderComponentsSet(&collider_query);
             let shape = Cuboid::new(Vec2::new(0.5, 0.5).into());
+            let range = viewshed.range as f32;
             let visibility_grid = VisibilityGrid(map, |coord: Coord| {
+                if start.x_i32() == coord.x && start.y_i32() == coord.y {
+                    return 0;
+                } else if coord.distance(start) > range {
+                    return 255;
+                }
                 let shape_pos = (Vec2::new(coord.x as f32, coord.y as f32), 0.);
                 let mut opacity = 0;
                 query_pipeline.intersections_with_shape(
@@ -107,7 +123,9 @@ fn update_viewshed<'a>(
                     &shape_pos.into(),
                     &shape,
                     InteractionGroups::all(),
-                    Some(&|v| blocks_visibility.get(v.entity()).is_ok()),
+                    Some(&|v| {
+                        v.entity() != viewer_entity && blocks_visibility.get(v.entity()).is_ok()
+                    }),
                     |_| {
                         opacity = 255;
                         false