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WasmGPU.compute.readback.readScalarU32

Summary

WasmGPU.compute.readback.readScalarU32 reads one u32 scalar from a GPU source. It is a convenience wrapper for counter-like outputs where only one unsigned value is needed. Use this for histogram totals, compacted-count outputs, and index reductions. Source offsets are byte-based and must satisfy readback alignment requirements.

Syntax

WasmGPU.compute.readback.readScalarU32(src: ReadbackSource, srcOffsetBytes?: number, opts?: { label?: string }): Promise<number>
const value = await wgpu.compute.readback.readScalarU32(src, srcOffsetBytes, opts);

Parameters

Name Type Required Description
src ReadbackSource Yes Source GPU buffer to read from.
srcOffsetBytes number No Byte offset where the scalar starts (default 0).
opts { label?: string } No Optional debug label for readback instrumentation.

Returns

Promise<number> - Resolves to the unsigned 32-bit scalar value.

Example

const canvas = document.querySelector("canvas");
const wgpu = await WasmGPU.create(canvas);

const storage = wgpu.compute.createStorageBuffer({ data: new Uint32Array([123]), copySrc: true });
const value = await wgpu.compute.readback.readScalarU32(storage);

console.log(value);

See Also