Change default descriptor binding to be VkMutable (#7224)

* change default descriptor binding to be VkMutable

4 files changed, 34 insertions, 11 deletions

diff --git a/docs/user-guide/03-convenience-features.md b/docs/user-guide/03-convenience-features.md
index d522daf81..948809110 100644
--- a/docs/user-guide/03-convenience-features.md
+++ b/docs/user-guide/03-convenience-features.md
@@ -610,12 +610,12 @@ Default behavior assigns binding-indicies based on descriptor types:
 | Sampler                | VK_DESCRIPTOR_TYPE_SAMPLER                | 0             |
 | CombinedTextureSampler | VK_DESCRIPTOR_TYPE_COMBINED_IMAGE_SAMPLER | 1             |
 | Texture_Read           | VK_DESCRIPTOR_TYPE_SAMPLED_IMAGE          | 2             |
-| Texture_ReadWrite      | VK_DESCRIPTOR_TYPE_STORAGE_IMAGE          | 3             |
-| TexelBuffer_Read       | VK_DESCRIPTOR_TYPE_UNIFORM_TEXEL_BUFFER   | 4             |
-| TexelBuffer_ReadWrite  | VK_DESCRIPTOR_TYPE_STORAGE_TEXEL_BUFFER   | 5             |
-| Buffer_Read            | VK_DESCRIPTOR_TYPE_UNIFORM_BUFFER         | 6             |
-| Buffer_ReadWrite       | VK_DESCRIPTOR_TYPE_STORAGE_BUFFER         | 7             |
-| Unknown                | Other                                     | 8             |
+| Texture_ReadWrite      | VK_DESCRIPTOR_TYPE_STORAGE_IMAGE          | 2             |
+| TexelBuffer_Read       | VK_DESCRIPTOR_TYPE_UNIFORM_TEXEL_BUFFER   | 2             |
+| TexelBuffer_ReadWrite  | VK_DESCRIPTOR_TYPE_STORAGE_TEXEL_BUFFER   | 2             |
+| Buffer_Read            | VK_DESCRIPTOR_TYPE_UNIFORM_BUFFER         | 2             |
+| Buffer_ReadWrite       | VK_DESCRIPTOR_TYPE_STORAGE_BUFFER         | 2             |
+| Unknown                | Other                                     | 3             |
 
 > `ACCELERATION_STRUCTURE` is excluded from the list of types since Slang by default uses the handle to a `RaytracingAccelerationStructure` as a GPU address, casting the handle to a `RaytracingAccelerationStructure`. This removes the need for a binding-slot of `RaytracingAccelerationStructure`.
 
@@ -672,11 +672,24 @@ Additionally, `defaultGetDescriptorFromHandle()` takes an optional argument whos
  ```slang
 public enum BindlessDescriptorOptions
 {
-    None = 0, /// Bind assuming regular binding model rules.
-    VkMutable = 1, /// Bind assuming `VK_EXT_mutable_descriptor_type` without mutable `AccelerationStructure` binding support.
+    None = 0,      /// Bind assuming regular binding model rules.
+    VkMutable = 1, /// **Current Default** Bind assuming `VK_EXT_mutable_descriptor_type`
 }
  ```
 
+`None` provides the following bindings for descriptor types:
+| Enum Value             | Vulkan Descriptor Type                    | Binding Index |
+|------------------------|-------------------------------------------|---------------|
+| Sampler                | VK_DESCRIPTOR_TYPE_SAMPLER                | 0             |
+| CombinedTextureSampler | VK_DESCRIPTOR_TYPE_COMBINED_IMAGE_SAMPLER | 1             |
+| Texture_Read           | VK_DESCRIPTOR_TYPE_SAMPLED_IMAGE          | 2             |
+| Texture_ReadWrite      | VK_DESCRIPTOR_TYPE_STORAGE_IMAGE          | 3             |
+| TexelBuffer_Read       | VK_DESCRIPTOR_TYPE_UNIFORM_TEXEL_BUFFER   | 4             |
+| TexelBuffer_ReadWrite  | VK_DESCRIPTOR_TYPE_STORAGE_TEXEL_BUFFER   | 5             |
+| Buffer_Read            | VK_DESCRIPTOR_TYPE_UNIFORM_BUFFER         | 6             |
+| Buffer_ReadWrite       | VK_DESCRIPTOR_TYPE_STORAGE_BUFFER         | 7             |
+| Unknown                | Other                                     | 8             |
+
 `VkMutable` provides the following bindings for descriptor types:
 | Enum Value             | Vulkan Descriptor Type                    | Binding Index |
 |------------------------|-------------------------------------------|---------------|
diff --git a/source/slang/hlsl.meta.slang b/source/slang/hlsl.meta.slang
index 9b15392ec..801c61481 100644
--- a/source/slang/hlsl.meta.slang
+++ b/source/slang/hlsl.meta.slang
@@ -22749,14 +22749,14 @@ T __castDescriptorHandleToResource<T:IOpaqueDescriptor>(DescriptorHandle<T> ptr)
 
 public enum BindlessDescriptorOptions
 {
-    None = 0, /// Bind assuming regular binding model rules.
-    VkMutable = 1, /// Bind assuming `VK_EXT_mutable_descriptor_type` without mutable `AccelerationStructure` binding support.
+    None = 0,      /// Bind assuming regular binding model rules.
+    VkMutable = 1, /// **Current Default** Bind assuming `VK_EXT_mutable_descriptor_type`
 }
 
 /// The default implementation of `getDescriptorFromHandle`, which converts from a descriptor handle
 /// to a descriptor object.
 [ForceInline]
-T defaultGetDescriptorFromHandle<T:IOpaqueDescriptor>(DescriptorHandle<T> handleValue, constexpr BindlessDescriptorOptions bindlessOptions = BindlessDescriptorOptions.None)
+T defaultGetDescriptorFromHandle<T:IOpaqueDescriptor>(DescriptorHandle<T> handleValue, constexpr BindlessDescriptorOptions bindlessOptions = BindlessDescriptorOptions.VkMutable)
 {
     __target_switch
     {
diff --git a/tests/language-feature/descriptor-handle/desc-handle-default.slang b/tests/language-feature/descriptor-handle/desc-handle-default.slang
index d442fb610..016b04bfb 100644
--- a/tests/language-feature/descriptor-handle/desc-handle-default.slang
+++ b/tests/language-feature/descriptor-handle/desc-handle-default.slang
@@ -10,6 +10,12 @@
 //TEST:SIMPLE(filecheck=SAMPLED_IMAGE): -target spirv -stage compute -entry computeMain -DSAMPLED_IMAGE
 //TEST:SIMPLE(filecheck=MIX): -target spirv -stage compute -entry computeMain -DSAMPLER -DSTORAGE_TEXEL_BUFFER -DUNIFORM_BUFFER -DACCELERATION_STRUCTURE
 
+
+export T getDescriptorFromHandle<T : IOpaqueDescriptor>(DescriptorHandle<T> handleValue)
+{
+    return defaultGetDescriptorFromHandle(handleValue, BindlessDescriptorOptions.None);
+}
+
 // To intentionally fill up binding slots
 [[vk::binding(0, 1)]]
 RWTexture1D<float> t1;
diff --git a/tests/language-feature/descriptor-handle/desc-handle-vk-mutable-descriptor.slang b/tests/language-feature/descriptor-handle/desc-handle-vk-mutable-descriptor.slang
index 8fc2d3283..2bf57d0ef 100644
--- a/tests/language-feature/descriptor-handle/desc-handle-vk-mutable-descriptor.slang
+++ b/tests/language-feature/descriptor-handle/desc-handle-vk-mutable-descriptor.slang
@@ -1,4 +1,5 @@
 //TEST:SIMPLE(filecheck=CHECK): -target spirv -stage compute -entry computeMain
+//TEST:SIMPLE(filecheck=CHECK): -target spirv -stage compute -entry computeMain -DIS_DEFAULT
 
 // To intentionally fill up binding slots
 [[vk::binding(0, 1)]]
@@ -25,10 +26,13 @@ Texture1D<float> t4;
 //CHECK-NOT: OpDecorate %__slang_resource_heap{{.*}} Binding 7
 //CHECK-NOT: OpDecorate %__slang_resource_heap{{.*}} Binding 8
 //CHECK-NOT: OpDecorate %__slang_resource_heap{{.*}} Binding 9
+
+#ifndef IS_DEFAULT
 export T getDescriptorFromHandle<T:IOpaqueDescriptor>(DescriptorHandle<T> handleValue)
 {
     return defaultGetDescriptorFromHandle(handleValue, BindlessDescriptorOptions.VkMutable);
 }
+#endif
 
 uniform SamplerState.Handle sampler;
 uniform Sampler1DShadow.Handle combinedSampler;