cwfitzgerald · November 26, 2025 16:00
diff --git a/0-resource_tables.rs b/0-resource_tables.rs
 ///// Rust strawman API for Resource Tables /////

 bitflags! {
    struct Features : u64 {
        // Supports only sampled texture + samplers in resource tables
        const SAMPLING_RESOURCE_TABLE = ..;
        // Supports all non-uniform resource types in resource tables
        const FULL_RESOURCE_TABLE = ..;
    }
 }

 struct Limits {
    // Maximum size of any single resource table. Higher is better.
    // Default something like 100k.
    max_resource_table_size: u32,
    // ..
 }

 struct PipelineLayoutDescriptor {
    resource_table_available: bool,
    // .. 
 };

 struct ResourceTableDescriptor {
    /// Maximum number of bindings in the resource table.
    size: u32,
 }
 impl Device {
    /// Creates a new resource table. The expectation is that there would be
    /// a relatively small number of these created during application lifetime,
    /// mostly for composability purposes.
    fn create_resource_table(ResourceTableDescriptor descriptor) -> ResourceTable;
 }

 enum BindingInUseError {
    BindingInUse,
    OutOfBounds(..),
    // ...
 }
 enum NoFreeBindingError {
    NoFreeBinding,
    /// ...
 }
 enum RemoveBindingError {
    AlreadyInUse,
    /// ...
 }

 struct ResourceTable {
    fn destroy();

    /// Immediately updates the binding at the given index. The index must be unused.
    ///
    /// BindingResource::*Array() variants are not allowed here and would be eventually removed.
    fn update(index: u32, entry: BindingResource) -> Result<(), BindingInUseError>;
    /// Inserts a binding at some index in the table. If there are no free slots, return an error.
    ///
    /// This function is guarenteed to return the _lowest_ index currently free slot.
    ///
    /// BindingResource::*Array() variants are not allowed here and would be eventually removed.
    fn insert_binding(entry: BindingResource) -> Result<u32, NoFreeBindingError>;
    /// Queues an operation that removes the given binding from the index. The index may
    /// not be re-used until after queue.on_submitted_work_done() would have completed.
    /// 
    /// See https://github.com/gpuweb/gpuweb/blob/main/proposals/bindless.md#updates-of-bindings-in-dynamic-binding-arrays
    /// for more discussion.
    fn remove_binding(index: u32) -> Result<(), RemoveBindingError>;
 };

 impl CommandEncoder {
    /// Can only ever have one bound resource table at a time. This should
    /// be expected to be relatively expensive, so avoid changing
    /// it frequently.
    fn set_resource_table(ResourceTable table);
 }
diff --git a/1-bindless.wgsl b/1-bindless.wgsl
 /// Strawman WGSL Syntax

 fn resourceTableLength() -> u32;
 fn getBinding<T>(index: u32) -> T
    where T: texture_*;
 fn hasBinding<T>(index: u32) -> bool;
 fn getBufferAt<T>(index: u32, offset: u32) -> T
    where T: StorageBufferCompatibleType;
diff --git a/2-bindless.glsl b/2-bindless.glsl
 /// Strawman GLSL/SPIR-V injestion syntax

 // All binding arrays bound to the shader will be redirected
 // to the resource table, regardless of their original binding numbers.
 // All point to the same heap. Can do vulkan style type aliasing. 
 layout(set = 0, binding = 0) uniform texture2D myTextureArray[];
 layout(set = 1, binding = 1) uniform texture3D myTextureArray[];
 layout(set = 2, binding = 2) buffer MyBufferArray {
    uint data[];
 } myBufferArray[];
diff --git a/3-bda.slang b/3-bda.slang
 /// Strawman BDA deguaring, using Slang for conciceness

 T* my_ptr;

 // OMG pointer addition + BDA
 my_ptr += 12;
 T = *my_ptr;

 // Pointer desugars to 32bit index into resource table and 32bit offset into buffer.
 // This behavior is well defined for wgpu-native-compatible spirv ingestion.
	///// Rust strawman API for Resource Tables /////

	bitflags! {
	struct Features : u64 {
	// Supports only sampled texture + samplers in resource tables
	const SAMPLING_RESOURCE_TABLE = ..;
	// Supports all non-uniform resource types in resource tables
	const FULL_RESOURCE_TABLE = ..;
	}
	}

	struct Limits {
	// Maximum size of any single resource table. Higher is better.
	// Default something like 100k.
	max_resource_table_size: u32,
	// ..
	}

	struct PipelineLayoutDescriptor {
	resource_table_available: bool,
	// ..
	};

	struct ResourceTableDescriptor {
	/// Maximum number of bindings in the resource table.
	size: u32,
	}
	impl Device {
	/// Creates a new resource table. The expectation is that there would be
	/// a relatively small number of these created during application lifetime,
	/// mostly for composability purposes.
	fn create_resource_table(ResourceTableDescriptor descriptor) -> ResourceTable;
	}

	enum BindingInUseError {
	BindingInUse,
	OutOfBounds(..),
	// ...
	}
	enum NoFreeBindingError {
	NoFreeBinding,
	/// ...
	}
	enum RemoveBindingError {
	AlreadyInUse,
	/// ...
	}

	struct ResourceTable {
	fn destroy();

	/// Immediately updates the binding at the given index. The index must be unused.
	///
	/// BindingResource::*Array() variants are not allowed here and would be eventually removed.
	fn update(index: u32, entry: BindingResource) -> Result<(), BindingInUseError>;
	/// Inserts a binding at some index in the table. If there are no free slots, return an error.
	///
	/// This function is guarenteed to return the _lowest_ index currently free slot.
	///
	/// BindingResource::*Array() variants are not allowed here and would be eventually removed.
	fn insert_binding(entry: BindingResource) -> Result<u32, NoFreeBindingError>;
	/// Queues an operation that removes the given binding from the index. The index may
	/// not be re-used until after queue.on_submitted_work_done() would have completed.
	///
	/// See https://github.com/gpuweb/gpuweb/blob/main/proposals/bindless.md#updates-of-bindings-in-dynamic-binding-arrays
	/// for more discussion.
	fn remove_binding(index: u32) -> Result<(), RemoveBindingError>;
	};

	impl CommandEncoder {
	/// Can only ever have one bound resource table at a time. This should
	/// be expected to be relatively expensive, so avoid changing
	/// it frequently.
	fn set_resource_table(ResourceTable table);
	}
	/// Strawman WGSL Syntax

	fn resourceTableLength() -> u32;
	fn getBinding<T>(index: u32) -> T
	where T: texture_*;
	fn hasBinding<T>(index: u32) -> bool;
	fn getBufferAt<T>(index: u32, offset: u32) -> T
	where T: StorageBufferCompatibleType;
	/// Strawman GLSL/SPIR-V injestion syntax

	// All binding arrays bound to the shader will be redirected
	// to the resource table, regardless of their original binding numbers.
	// All point to the same heap. Can do vulkan style type aliasing.
	layout(set = 0, binding = 0) uniform texture2D myTextureArray[];
	layout(set = 1, binding = 1) uniform texture3D myTextureArray[];
	layout(set = 2, binding = 2) buffer MyBufferArray {
	uint data[];
	} myBufferArray[];
	/// Strawman BDA deguaring, using Slang for conciceness

	T* my_ptr;

	// OMG pointer addition + BDA
	my_ptr += 12;
	T = *my_ptr;

	// Pointer desugars to 32bit index into resource table and 32bit offset into buffer.
	// This behavior is well defined for wgpu-native-compatible spirv ingestion.