From a2044aefe7fd0dc4be42684d3bded2c645dc5d92 Mon Sep 17 00:00:00 2001
From: Erich Gubler <erichdongubler@gmail.com>
Date: Wed, 13 Nov 2024 07:20:02 -0500
Subject: [PATCH] fix: allow non-filterable float on derived BGLs for texture
 binding usage w/ no sampler (#6531)

---
 CHANGELOG.md                |  1 +
 wgpu-core/src/validation.rs | 18 +++++++++++++-----
 2 files changed, 14 insertions(+), 5 deletions(-)

diff --git a/CHANGELOG.md b/CHANGELOG.md
index 36f88095f..dbd395822 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -127,6 +127,7 @@ By @ErichDonGubler in [#6456](https://github.com/gfx-rs/wgpu/pull/6456), [#6148]
 - Ensure that `Features::TIMESTAMP_QUERY` is set when using timestamp writes in render and compute passes. By @ErichDonGubler in [#6497](https://github.com/gfx-rs/wgpu/pull/6497).
 - Check for device mismatches when beginning render and compute passes. By @ErichDonGubler in [#6497](https://github.com/gfx-rs/wgpu/pull/6497). 
 - Lower `QUERY_SET_MAX_QUERIES` (and enforced limits) from 8192 to 4096 to match WebGPU spec. By @ErichDonGubler in [#6525](https://github.com/gfx-rs/wgpu/pull/6525).
+- Allow non-filterable float on texture bindings never used with samplers when using a derived bind group layout. By @ErichDonGubler in [#6531](https://github.com/gfx-rs/wgpu/pull/6531/).
 
 #### Naga
 
diff --git a/wgpu-core/src/validation.rs b/wgpu-core/src/validation.rs
index 13cf443d4..68a9288e0 100644
--- a/wgpu-core/src/validation.rs
+++ b/wgpu-core/src/validation.rs
@@ -497,7 +497,10 @@ impl Resource {
         Ok(())
     }
 
-    fn derive_binding_type(&self) -> Result<BindingType, BindingError> {
+    fn derive_binding_type(
+        &self,
+        is_reffed_by_sampler_in_entrypoint: bool,
+    ) -> Result<BindingType, BindingError> {
         Ok(match self.ty {
             ResourceType::Buffer { size } => BindingType::Buffer {
                 ty: match self.class {
@@ -531,9 +534,9 @@ impl Resource {
                 match class {
                     naga::ImageClass::Sampled { multi, kind } => BindingType::Texture {
                         sample_type: match kind {
-                            naga::ScalarKind::Float => {
-                                wgt::TextureSampleType::Float { filterable: true }
-                            }
+                            naga::ScalarKind::Float => wgt::TextureSampleType::Float {
+                                filterable: is_reffed_by_sampler_in_entrypoint,
+                            },
                             naga::ScalarKind::Sint => wgt::TextureSampleType::Sint,
                             naga::ScalarKind::Uint => wgt::TextureSampleType::Uint,
                             naga::ScalarKind::AbstractInt
@@ -1009,7 +1012,12 @@ impl Interface {
                             break 'err Err(BindingError::Missing);
                         };
 
-                        let ty = match res.derive_binding_type() {
+                        let ty = match res.derive_binding_type(
+                            entry_point
+                                .sampling_pairs
+                                .iter()
+                                .any(|&(im, _samp)| im == handle),
+                        ) {
                             Ok(ty) => ty,
                             Err(error) => break 'err Err(error),
                         };