Task 1 of 5

Flip On the Pipeline

Until now, every kernel call ended the same way: the GPU finished computing, then the whole result was downloaded back to JavaScript as a typed array. That download is the expensive part — for a 512×512 grid it's a megabyte crossing the bus on every single call.

pipeline: true changes the ending. The kernel still runs the same, but the result stays in GPU memory, and what you get back is a texture — a lightweight handle to data that never left the card. Log one and you'll see an object, not numbers. When you actually want the values, you ask for the download explicitly with .toArray() — and since the download is a real trip across the bus, it is asynchronous like the kernel call itself: await result.toArray().

One backend wrinkle to know: the CPU backend has no textures, so there a pipeline kernel hands back a plain array — which has no .toArray at all. Mode-safe code uses the same guard gpu.js uses internally, with the await in front of the call it guards: result.toArray ? await result.toArray() : result. (Awaiting a plain array is a no-op, so that one line is correct on every backend.)

Goal: make the boost kernel a pipeline kernel, then download its result explicitly and log the first sample.

Requirements

Add pipeline: true to the kernel settings
Log the raw result — see what a texture looks like in the console
Download the values with await .toArray(), using the mode-safe guard
Log the first value as console.log('first sample:', values[0])

Hint 1 — where does the flag go?

pipeline: true sits in the settings object, right next to output. Nothing about the kernel function itself changes.

Hint 2 — the mode-safe download

const values = result.toArray ? await result.toArray() : result;

On a GPU backend this awaits toArray(); on the CPU backend result is already an array and passes through untouched.

Same idea elsewhere

A gpu.js texture is the same idea as a GPUBuffer you never map in WebGPU, or device memory behind a pointer in CUDA and ROCm: the data has an address on the card, and JavaScript only holds the ticket stub. .toArray() is the explicit "map it back to the host" step.

All tasks in Pipelines & Textures

This page is an interactive exercise — the editor, the GPU runner and your saved progress need JavaScript. The text above is the full brief.