From 80ab3a829ea209a4b30e898cdae830f505081f13 Mon Sep 17 00:00:00 2001
From: Aspen <fuzzyzilla01@gmail.com>
Date: Fri, 15 Sep 2023 13:22:55 -0700
Subject: [PATCH] Add interface entry for color index, check during overlap
 testing (#2333)

---
 vulkano/src/shader/mod.rs     |  4 ++++
 vulkano/src/shader/reflect.rs | 22 +++++++++++++++++-----
 2 files changed, 21 insertions(+), 5 deletions(-)

diff --git a/vulkano/src/shader/mod.rs b/vulkano/src/shader/mod.rs
index 71dfa88ffa..a18ee0080e 100644
--- a/vulkano/src/shader/mod.rs
+++ b/vulkano/src/shader/mod.rs
@@ -1314,6 +1314,10 @@ pub struct ShaderInterfaceEntry {
     /// The location slot that the variable starts at.
     pub location: u32,
 
+    /// The index within the location slot that the variable is located.
+    /// Only meaningful for fragment outputs.
+    pub index: u32,
+
     /// The component slot that the variable starts at. Must be in the range 0..=3.
     pub component: u32,
 
diff --git a/vulkano/src/shader/reflect.rs b/vulkano/src/shader/reflect.rs
index d44e55ecb7..f0d65774e6 100644
--- a/vulkano/src/shader/reflect.rs
+++ b/vulkano/src/shader/reflect.rs
@@ -1197,12 +1197,23 @@ fn shader_interface(
                     _ => None,
                 })
                 .unwrap_or(0);
+            let index = id_info
+                .iter_decoration()
+                .find_map(|instruction| match *instruction {
+                    Instruction::Decorate {
+                        decoration: Decoration::Index { index },
+                        ..
+                    } => Some(index),
+                    _ => None,
+                })
+                .unwrap_or(0);
 
             let ty = shader_interface_type_of(spirv, result_type_id, ignore_first_array);
             assert!(ty.num_elements >= 1);
 
             Some(ShaderInterfaceEntry {
                 location,
+                index,
                 component,
                 ty,
                 name,
@@ -1213,11 +1224,12 @@ fn shader_interface(
     // Checking for overlapping elements.
     for (offset, element1) in elements.iter().enumerate() {
         for element2 in elements.iter().skip(offset + 1) {
-            if element1.location == element2.location
-                || (element1.location < element2.location
-                    && element1.location + element1.ty.num_locations() > element2.location)
-                || (element2.location < element1.location
-                    && element2.location + element2.ty.num_locations() > element1.location)
+            if element1.index == element2.index
+                && (element1.location == element2.location
+                    || (element1.location < element2.location
+                        && element1.location + element1.ty.num_locations() > element2.location)
+                    || (element2.location < element1.location
+                        && element2.location + element2.ty.num_locations() > element1.location))
             {
                 panic!(
                     "The locations of attributes `{:?}` ({}..{}) and `{:?}` ({}..{}) overlap",