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WebGPU · 02 Negotiating Features and limits
Series contents · Technology map
Stage: Device and Command Fundamentals · Editable example · Storage ID: webgpu-step-02
Goals and learning outcomes
- Negotiate device features.
- Write input checks based on limits.
Prerequisites
Continue using the output and notes from unit 1. Preserve the previous inputs and reference outputs before the Negotiating Features and limits experiment.
Key concepts and explanations
Optional Features
Not every adapter provides the same optional features. Check the supported list before requesting a feature you need.
Limits
Resource sizes and binding counts have device limits. Restrict inputs according to device.limits instead of guessing large values.
Practice setup
First read the execution-scope guidance on the example screen. The following preparation is for extending the assignment in a separate project. This is a document-guided exercise to implement yourself in a separate localhost or HTTPS project. Check the secure context, navigator.gpu, and adapter request result, and provide an unsupported-environment message. Preserve device.lost handling and resource release.
The linked example is a starting point. It does not implement every task below. Complete work beyond its supported scope in a separate project.
Practice tasks
- In capabilities.js, display only the required adapter.features and limits entries in a table.
- Write a requestDevice descriptor that distinguishes required and optional features.
- Disable unsupported optional features and validate the maximum buffer-size input.
Variables to observe
| Variable | Baseline | Change | Expected change / hypothesis |
|---|---|---|---|
| Optional feature | Disabled | Request after checking support | The feature is expected to be enabled only on supported devices, with the default path retained elsewhere. |
Predictions in this table are not measured results. Change one condition at a time and record why the actual result differs.
Completion criteria
- State required and optional features separately.
- Reject inputs exceeding limits before creating resources.
Self-check
- Why distinguish adapter limits from requested device limits?
- Must an optional-feature failure shut down the entire app?
Official references
Linked example and execution scope
Example source · Runtime environments and limits
Runs real WebGPU/WGSL. Requires HTTPS/localhost and a supported adapter; unsupported environments display a reason, and CPU results are not substituted for GPU results.
Source code and records are not overwritten automatically. Resetting an existing example also preserves your notes.
Next learning
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