From 32fdcc1c1c4c390dc61d9a1f16ff7a5c35659330 Mon Sep 17 00:00:00 2001
From: Joshua Yanovski <pythonesque@gmail.com>
Date: Tue, 5 Jul 2022 23:00:05 -0700
Subject: [PATCH] Fix iteration area.

I'm pretty sure this bug already existed on master, so if the
performance degradation is unacceptable, we can revert.
---
 world/benches/site2.rs  |  8 ++++----
 world/src/layer/tree.rs | 14 ++++++++++++--
 2 files changed, 16 insertions(+), 6 deletions(-)

diff --git a/world/benches/site2.rs b/world/benches/site2.rs
index 879633227d..6425f5ce95 100644
--- a/world/benches/site2.rs
+++ b/world/benches/site2.rs
@@ -305,8 +305,8 @@ fn dungeon(c: &mut Criterion) {
         // let chunk_pos = Vec2::new(842, 839);
         // let chunk_pos = Vec2::new(24507/32, 20682/32);
         // let chunk_pos = Vec2::new(19638/32, 19621/32);
-        let chunk_pos = Vec2::new(21488/32, 13584/32);
-        // let chunk_pos = Vec2::new(21488/32 + 5, 13584/32 + 5);
+        // let chunk_pos = Vec2::new(21488/32, 13584/32);
+        let chunk_pos = Vec2::new(21488/32 + 5, 13584/32 + 5);
         b.iter(|| {
             black_box(world.generate_chunk(index.as_index_ref(), chunk_pos, || false, None));
         });
@@ -319,8 +319,8 @@ fn dungeon(c: &mut Criterion) {
         // let chunk_pos = Vec2::new(842, 839);
         // let chunk_pos = Vec2::new(24507/32, 20682/32);
         // let chunk_pos = Vec2::new(19638/32, 19621/32);
-        let chunk_pos = Vec2::new(21488/32, 13584/32);
-        // let chunk_pos = Vec2::new(21488/32 + 5, 13584/32 + 5);
+        // let chunk_pos = Vec2::new(21488/32, 13584/32);
+        let chunk_pos = Vec2::new(21488/32 + 5, 13584/32 + 5);
         let chunk = world.generate_chunk(index.as_index_ref(), chunk_pos, || false, None).unwrap().0;
         /* println!("{:?}", chunk.sub_chunks_len());
         let chunk = chunk.sub_chunks().next().unwrap(); */
diff --git a/world/src/layer/tree.rs b/world/src/layer/tree.rs
index 963e472548..9a785b7127 100644
--- a/world/src/layer/tree.rs
+++ b/world/src/layer/tree.rs
@@ -122,17 +122,27 @@ pub fn apply_trees_to(
     let calendar = info.calendar();
     /* let mut tree_cache = StructureGenCache::new(info.chunks().gen_ctx.structure_gen.clone()); */
 
+    let area_size = Vec2::from(info.area().size().map(|e| e as i32));
+
     // Get all the trees in range.
     let render_area = Aabr {
         min: info.wpos(),
-        max: info.wpos() + Vec2::from(info.area().size().map(|e| e as i32)),
+        max: info.wpos() + area_size,
+    };
+
+    // Maximum area we have to check for tree origins.
+    let witness_area = Aabr {
+        min: info.wpos() - area_size,
+        max: info.wpos() + Vec2::from(info.area().size().map(|e| e as i32)) + area_size,
     };
 
     let mut arena = bumpalo::Bump::new();
 
     /*canvas.foreach_col(|canvas, wpos2d, col| {*/
     info.chunks()
-        .get_area_trees(render_area.min + 15, render_area.max + 16)
+        // TODO: These should be in terms of some combination of frequency and chunk size.
+        .get_area_trees(render_area.min - 8, render_area.max + 16)
+        .filter(|attr| witness_area.contains_point(attr.pos))
         .filter_map(|attr| {
             info.col_or_gen(attr.pos)
                 .filter(|col| tree_valid_at(col, attr.seed))