From 22489f50da5a258b85a517e8d30a4949084b4bda Mon Sep 17 00:00:00 2001
From: xfy <i@rua.plus>
Date: Tue, 14 Jul 2026 15:00:05 +0800
Subject: [PATCH] fix: group conflicting Transform queries in ParamSet to fix
 B0001 panic
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resize_offscreen declared two Query<&mut Transform> params (FullscreenQuad
and UpscaleQuad filters). Bevy's conflict checker does not treat With<T>
filters as disjoint access — both queries declare write access to the same
component, so the app panicked at startup with error[B0001].

Merge the two queries into a ParamSet (borrowed one at a time) and move
them to the end of the parameter list per the Params convention.
---
 src/render/plugin.rs | 13 +++++++++----
 1 file changed, 9 insertions(+), 4 deletions(-)

diff --git a/src/render/plugin.rs b/src/render/plugin.rs
index bbf12f2..f4f83cf 100644
--- a/src/render/plugin.rs
+++ b/src/render/plugin.rs
@@ -145,10 +145,15 @@ fn resize_offscreen(
     mut images: ResMut<Assets<Image>>,
     params: Res<crate::params::BlackHoleParams>,
     target: Query<&OffscreenTarget>,
-    mut bh_quad: Query<&mut Transform, With<FullscreenQuad>>,
-    mut up_quad: Query<&mut Transform, With<UpscaleQuad>>,
     window: Query<&Window>,
     mut resized: MessageReader<bevy::window::WindowResized>,
+    // Both queries borrow `&mut Transform`. Bevy's conflict checker does not
+    // treat `With<T>` filters as disjoint access, so two such Query params would
+    // trip B0001 — they must be grouped in a ParamSet (borrowed one at a time).
+    mut quads: ParamSet<(
+        Query<&mut Transform, With<FullscreenQuad>>,
+        Query<&mut Transform, With<UpscaleQuad>>,
+    )>,
 ) {
     if resized.read().next().is_none() {
         return;
@@ -164,10 +169,10 @@ fn resize_offscreen(
         // insert is harmless — it'll succeed on the next WindowResized.
         let _ = images.insert(handle.0.id(), img);
     }
-    for mut t in &mut bh_quad {
+    for mut t in &mut quads.p0() {
         t.scale = Vec3::new(w as f32 / 2.0, h as f32 / 2.0, 1.0);
     }
-    for mut t in &mut up_quad {
+    for mut t in &mut quads.p1() {
         t.scale = Vec3::new(win.width() / 2.0, win.height() / 2.0, 1.0);
     }
 }