Implement binding array splitting

README.md

@@ -19,6 +19,7 @@ At the moment, the following transformations are supported:
 | --------------------------------- | ----------- | ------ | ------ |
 | Combined Image Samplers           | ✅          | ✅     | ✅     |
 | Immediates (Push Constants)       | ✅          | ✅\*   | ✅     |
+| Binding Arrays                    | ✅          | ✅     | ✅     |
 | Mixed Depth / Comparison          | ✅          | ⚠️\*   | ❌     |
 | isnan / isinf Patching            | ✅          | ✅     | ✅     |
 | Storage Cube Patching             | ✅          | ✅     | ✅     |
@@ -89,7 +90,6 @@ layout(std140, set = N+1, binding = 0) uniform PushBlock {
 } pc;
 
 // where N is the max set in the shader.
-
 ```
 
 ### Additional Notes
@@ -110,6 +110,69 @@ layout(std140, set = N+1, binding = 0) uniform PushBlock {
 
 > \* naga's SPIR-V front-end rejects `MatrixStride 16` for `mat2x2`, this should be fixed soon (?).
 
+## Binding Arrays 
+
+Binding arrays are a feature commonly used in shaders and supported by WGSL compilers, just not on the web (yet?).
+This patch takes fixed size arrays of size N containing opaque or concrete types and splits them into N individual bindings.
+In `wgpu`, this covers following features: 
+
+- `TEXTURE_BINDING_ARRAY`
+- `BUFFER_BINDING_ARRAY`
+- `STORAGE_RESOURCE_BINDING_ARRAY`
+- `SAMPLED_TEXTURE_AND_STORAGE_BUFFER_ARRAY_NON_UNIFORM_INDEXING`
+- `STORAGE_TEXTURE_ARRAY_NON_UNIFORM_INDEXING`
+
+```glsl
+struct Thing {
+    float a;
+};
+
+#define MAX_RESOURCES 2
+layout(set = 0, binding = 0) uniform sampler u_samplers[MAX_RESOURCES];
+layout(set = 0, binding = 1) uniform texture2D u_textures[MAX_RESOURCES];
+layout(set = 0, binding = 2) uniform texture2DArray u_texture_arrays[MAX_RESOURCES];
+layout(set = 0, binding = 3) uniform image2D u_images[MAX_RESOURCES];
+layout(set = 0, binding = 4) uniform Thing u_things[MAX_RESOURCES];
+layout(set = 0, binding = 5, std140) buffer Thing u_buf_things[MAX_RESOURCES];
+
+// is converted into...
+
+struct Thing {
+    float a;
+};
+
+layout(set = 0, binding = 0) uniform sampler u_samplers_0;
+layout(set = 0, binding = 1) uniform sampler u_samplers_1;
+layout(set = 0, binding = 2) uniform texture2D u_textures_0;
+layout(set = 0, binding = 3) uniform texture2D u_textures_1;
+layout(set = 0, binding = 4) uniform texture2DArray u_texture_arrays_0;
+layout(set = 0, binding = 5) uniform texture2DArray u_texture_arrays_1;
+layout(set = 0, binding = 6) uniform image2D u_images_0;
+layout(set = 0, binding = 7) uniform image2D u_images_1;
+layout(set = 0, binding = 8) uniform Thing u_things_0;
+layout(set = 0, binding = 9) uniform Thing u_things_1;
+layout(set = 0, binding = 10, std140) buffer Thing u_buf_things_0;
+layout(set = 0, binding = 11, std140) buffer Thing u_buf_things_1;
+```
+
+### Additional Notes
+
+- Combined image samplers are not supported, please run the combined image sampler pass first.
+- Nested resources (`texture2D u[I][J][K]`) are not supported.
+- Usage of additional SPIR-V capabilities such as `SparseResidency` or `ImageQuery` are not supported.
+
+### Tests
+
+| Test                                  | `spirv-val` | Naga   | Tint |
+| ------------------------------------- | ----------- | ------ | ---- |
+| `buffer_binding_array.frag`           | ✅          | ✅     | ✅   |
+| `storage_binding_array.frag`          | ✅          | ✅     | ✅   |
+| `texture_binding_array.frag`          | ✅          | ✅     | ✅   |
+| `nested_texture_binding_array.frag`   | ✅          | ✅     | ✅   |
+| `sampler_binding_array.frag`          | ✅          | ✅     | ✅   |
+| `sampler_stub.frag`                   | ✅          | ✅     | ✅   |
+| `texture_array_binding_array.frag`    | ✅          | ✅     | ✅   |
+
 ## Mixed Depth / Comparison
 
 The WGSL spec differentiates between `sampler` and `sampler_comparison` as well as `texture2d<T>` and `texture_depth_2d`.

ffi/bin/README.txt

@@ -0,0 +1,2 @@
+Make sure to update this guy when a new patch is included in the API.
+The main purpose of this file is not to test functionality but linking!

ffi/bin/spv_webgpu_transform.c

@@ -40,6 +40,14 @@ int main() {
 	uint32_t pruneunuseddref_out_count;
 	spirv_webgpu_transform_pruneunuseddref_alloc(storagecube_out_spv, storagecube_out_count, &pruneunuseddref_out_spv, &pruneunuseddref_out_count);
 
+	uint32_t *immediates_out_spv;
+	uint32_t immediates_out_count;
+	spirv_webgpu_transform_immediatespatch_alloc(pruneunuseddref_out_spv, pruneunuseddref_out_count, &immediates_out_spv, &immediates_out_count);
+
+	uint32_t *splitbindingarray_out_spv;
+	uint32_t splitbindingarray_out_count;
+	spirv_webgpu_transform_splitbindingarray_alloc(immediates_out_spv, immediates_out_count, &splitbindingarray_out_spv, &splitbindingarray_out_count, &correction_map);
+
 	// 3. Observe the patched variables
 	print_set_binding(correction_map, 0, 0);
 	print_set_binding(correction_map, 0, 1);
@@ -51,6 +59,8 @@ int main() {
 	print_set_binding(correction_map, 3, 0);
 
 	// 4. Free memory
+	spirv_webgpu_transform_splitbindingarray_free(splitbindingarray_out_spv);
+	spirv_webgpu_transform_immediatespatch_free(immediates_out_spv);
 	spirv_webgpu_transform_pruneunuseddref_free(pruneunuseddref_out_spv);
 	spirv_webgpu_transform_storagecubepatch_free(storagecube_out_spv);
 	spirv_webgpu_transform_isnanisinfpatch_free(isnanisinf_out_spv);
@@ -88,6 +98,9 @@ void print_set_binding(TransformCorrectionMap map, uint32_t set, uint32_t bindin
 			case SPIRV_WEBGPU_TRANSFORM_CORRECTION_TYPE_CONVERT_STORAGE_CUBE:
 				printf("CONVERT_STORAGE_CUBE ");
 				break;
+			case SPIRV_WEBGPU_TRANSFORM_CORRECTION_TYPE_SPLIT_BINDING_ARRAY:
+				printf("SPLIT_BINDING_ARRAY ");
+				break;
 		}
 	}
 	printf("\n");

ffi/spirv_webgpu_transform.h

@@ -23,6 +23,8 @@ void spirv_webgpu_transform_storagecubepatch_alloc(uint32_t *in_spv, uint32_t in
 void spirv_webgpu_transform_storagecubepatch_free(uint32_t *out_spv);
 void spirv_webgpu_transform_pruneunuseddref_alloc(uint32_t *int_spv, uint32_t in_count, uint32_t **out_spv, uint32_t *out_count);
 void spirv_webgpu_transform_pruneunuseddref_free(uint32_t *out_spv);
+void spirv_webgpu_transform_splitbindingarray_alloc(uint32_t *in_spv, uint32_t in_count, uint32_t **out_spv, uint32_t *out_count, TransformCorrectionMap *correction_map);
+void spirv_webgpu_transform_splitbindingarray_free(uint32_t *out_spv);
 
 void spirv_webgpu_transform_mirrorpatch_alloc(
 		uint32_t *in_left_spv, uint32_t in_left_count, TransformCorrectionMap *left_corrections,
@@ -41,6 +43,7 @@ typedef enum {
 	SPIRV_WEBGPU_TRANSFORM_CORRECTION_TYPE_SPLIT_DREF_REGULAR = 1,
 	SPIRV_WEBGPU_TRANSFORM_CORRECTION_TYPE_SPLIT_DREF_COMPARISON = 2,
 	SPIRV_WEBGPU_TRANSFORM_CORRECTION_TYPE_CONVERT_STORAGE_CUBE = 3,
+	SPIRV_WEBGPU_TRANSFORM_CORRECTION_TYPE_SPLIT_BINDING_ARRAY = 4,
 } TransformCorrectionType;
 
 // SAFETY: `corrections` invalidates when `correction_map` is written to.

ffi/src/lib.rs

@@ -3,7 +3,7 @@
 use core::{ffi, ptr, slice};
 use spirv_webgpu_transform::{
     CorrectionMap, combimgsampsplitter, drefsplitter, immediatespatch, isnanisinfpatch,
-    mirrorpatch, pruneunuseddref, storagecubepatch,
+    mirrorpatch, pruneunuseddref, splitbindingarray, storagecubepatch,
 };
 
 type TransformCorrectionMap = *mut ffi::c_void;
@@ -199,6 +199,35 @@ pub unsafe extern "C" fn spirv_webgpu_transform_pruneunuseddref_free(out_spv: *m
     unsafe { drop(Box::from_raw(out_spv)) }
 }
 
+#[unsafe(no_mangle)]
+pub unsafe extern "C" fn spirv_webgpu_transform_splitbindingarray_alloc(
+    in_spv: *const u32,
+    in_count: u32,
+    out_spv: *mut *const u32,
+    out_count: *mut u32,
+    correction_map: *mut TransformCorrectionMap,
+) {
+    let correction_map = unsafe { alloc_or_pass_correction_map(correction_map) };
+
+    let in_spv = unsafe { slice::from_raw_parts(in_spv, in_count as usize) };
+    match splitbindingarray(in_spv, correction_map) {
+        Ok(spv) => unsafe {
+            *out_count = spv.len() as u32;
+            let leaked = Box::leak(spv.into_boxed_slice());
+            *out_spv = leaked.as_ptr();
+        },
+        Err(_) => unsafe {
+            *out_spv = ptr::null();
+            *out_count = 0;
+        },
+    }
+}
+
+#[unsafe(no_mangle)]
+pub unsafe extern "C" fn spirv_webgpu_transform_splitbindingarray_free(out_spv: *mut u32) {
+    unsafe { drop(Box::from_raw(out_spv)) }
+}
+
 #[unsafe(no_mangle)]
 pub unsafe extern "C" fn spirv_webgpu_transform_mirrorpatch_alloc(
     in_left_spv: *const u32,
@@ -267,6 +296,8 @@ pub enum TransformCorrectionType {
     SpirvWebgpuTransformCorrectionTypeSplitCombined = 0,
     SpirvWebgpuTransformCorrectionTypeSplitDrefRegular = 1,
     SpirvWebgpuTransformCorrectionTypeSplitDrefComparison = 2,
+    SpirvWebgpuTransformCorrectionTypeConvertStorageCube = 3,
+    SpirvWebgpuTransformCorrectionTypeSplitBindingArray = 4,
 }
 
 // TransformCorrectionStatus spirv_webgpu_transform_correction_map_index(uint32_t set, uint32_t binding, TransformCorrectionType** corrections_ptr, uint32_t* correction_count);

src/bin/spv_webgpu_transform.rs

@@ -5,7 +5,7 @@ fn main() {
 
     if args.len() != 4 {
         eprintln!(
-            "Usage: spv_webgpu_transform <combimg|dref|isnanisinf|storagecube|pruneunuseddref|immediates> <input.spv> <output.spv>"
+            "Usage: spv_webgpu_transform <combimg|dref|isnanisinf|storagecube|pruneunuseddref|immediates|bindingarray> <input.spv> <output.spv>"
         );
         process::exit(1);
     }
@@ -32,6 +32,9 @@ fn main() {
         }
         "pruneunuseddref" => spirv_webgpu_transform::pruneunuseddref(&spv).unwrap(),
         "immediates" => spirv_webgpu_transform::immediatespatch(&spv).unwrap(),
+        "bindingarray" => {
+            spirv_webgpu_transform::splitbindingarray(&spv, &mut out_correction_map).unwrap()
+        }
         mode => {
             eprintln!("unknown mode {:?}", mode);
             process::exit(1)

src/correction.rs

@@ -3,18 +3,20 @@ use super::*;
 // Q: Hey what happens when you stack corrections?
 // A: I don't want to think about it... I will start thinking after a refactor...
 
-#[repr(u16)]
 #[derive(Debug, Clone, Copy, PartialEq, Eq, Hash)]
 pub enum CorrectionType {
     /// A combined image sampler has been split, a new `sampler` object should be inserted.
-    SplitCombined = 0,
+    SplitCombined,
     /// A mixed depth texture / sampler has been duplicated, insert the same object again with a `Regular` bind type.
-    SplitDrefRegular = 1,
+    SplitDrefRegular,
     /// A mixed depth texture / sampler has been duplicated, insert the same object again with a
     /// `Comparison` bind type.
-    SplitDrefComparison = 2,
+    SplitDrefComparison,
     /// A storage cube texture has been converted into a storage texture 2D array, change the dimension.
-    ConvertStorageCube = 3,
+    ConvertStorageCube,
+    /// A binding array has been split into new variables. Insert the same resource again.
+    /// For an `N` sized array, expect `N-1` entries.
+    SplitBindingArray,
 }
 
 #[derive(Debug, Clone, Default, PartialEq, Eq)]

src/lib.rs

@@ -10,6 +10,7 @@
 //! | --------------------------------- | ----------- | ------ | ------ |
 //! | Combined Image Samplers           | ✅          | ✅     | ✅     |
 //! | Immediates (Push Constants)       | ✅          | ✅\*   | ✅     |
+//! | Binding Arrays                    | ✅          | ✅     | ✅     |
 //! | Mixed Depth / Comparison          | ✅          | ⚠️\*   | ❌     |
 //! | isnan / isinf Patching            | ✅          | ✅     | ✅     |
 //! | Storage Cube Patching             | ✅          | ✅     | ✅     |
@@ -35,6 +36,7 @@ mod immediatespatch;
 mod isnanisinfpatch;
 mod mirrorpatch;
 mod pruneunuseddref;
+mod splitbindingarray;
 mod splitcombined;
 mod splitdref;
 mod spv;
@@ -52,6 +54,7 @@ pub use immediatespatch::*;
 pub use isnanisinfpatch::*;
 pub use mirrorpatch::*;
 pub use pruneunuseddref::*;
+pub use splitbindingarray::*;
 pub use splitcombined::*;
 pub use splitdref::*;
 pub use storagecubepatch::*;

src/mirrorpatch.rs

@@ -214,7 +214,7 @@ fn patch_spv_decorations(
             // Convert into affected decoration
             Ok(AffectedDecoration {
                 original_res_id: original_variable_id,
-                new_res_id,
+                new_res_ids: vec![new_res_id],
                 correction_type,
             })
         })

src/pruneunuseddref.rs

@@ -186,7 +186,6 @@ pub fn pruneunuseddref(in_spv: &[u32]) -> Result<Vec<u32>, ()> {
 
         new_spv[spv_idx..spv_idx + word_count].fill(encode_word(1, SPV_INSTRUCTION_OP_NOP));
     }
-
     prune_noops(&mut new_spv);
 
     // 10. Write New Header and New Code